lab util grade 100

Makefile

@@ -188,6 +188,11 @@ UPROGS=\
 	$U/_grind\
 	$U/_wc\
 	$U/_zombie\
+	$U/_sleep\
+	$U/_pingpong\
+	$U/_primes\
+	$U/_find\
+	$U/_xargs\
 
 
 

README

@@ -6,7 +6,7 @@ ACKNOWLEDGMENTS
 
 xv6 is inspired by John Lions's Commentary on UNIX 6th Edition (Peer
 to Peer Communications; ISBN: 1-57398-013-7; 1st edition (June 14,
-2000)).  See also https://pdos.csail.mit.edu/6.1810/, which provides
+2000)).  See also https://pdos.csail.mit.edu/6.828/, which provides
 pointers to on-line resources for v6.
 
 The following people have made contributions: Russ Cox (context switching,
@@ -14,31 +14,29 @@ locking), Cliff Frey (MP), Xiao Yu (MP), Nickolai Zeldovich, and Austin
 Clements.
 
 We are also grateful for the bug reports and patches contributed by
-Takahiro Aoyagi, Silas Boyd-Wickizer, Anton Burtsev, carlclone, Ian
+Takahiro Aoyagi, Silas Boyd-Wickizer, Anton Burtsev, Ian Chen, Dan
-Chen, Dan Cross, Cody Cutler, Mike CAT, Tej Chajed, Asami Doi,
+Cross, Cody Cutler, Mike CAT, Tej Chajed, Asami Doi, eyalz800, Nelson
-eyalz800, Nelson Elhage, Saar Ettinger, Alice Ferrazzi, Nathaniel
+Elhage, Saar Ettinger, Alice Ferrazzi, Nathaniel Filardo, flespark,
-Filardo, flespark, Peter Froehlich, Yakir Goaron, Shivam Handa, Matt
+Peter Froehlich, Yakir Goaron, Shivam Handa, Matt Harvey, Bryan Henry,
-Harvey, Bryan Henry, jaichenhengjie, Jim Huang, Matúš Jókay, John
+jaichenhengjie, Jim Huang, Matúš Jókay, Alexander Kapshuk, Anders
-Jolly, Alexander Kapshuk, Anders Kaseorg, kehao95, Wolfgang Keller,
+Kaseorg, kehao95, Wolfgang Keller, Jungwoo Kim, Jonathan Kimmitt,
-Jungwoo Kim, Jonathan Kimmitt, Eddie Kohler, Vadim Kolontsov, Austin
+Eddie Kohler, Vadim Kolontsov, Austin Liew, l0stman, Pavan
-Liew, l0stman, Pavan Maddamsetti, Imbar Marinescu, Yandong Mao, Matan
+Maddamsetti, Imbar Marinescu, Yandong Mao, Matan Shabtay, Hitoshi
-Shabtay, Hitoshi Mitake, Carmi Merimovich, Mark Morrissey, mtasm, Joel
+Mitake, Carmi Merimovich, Mark Morrissey, mtasm, Joel Nider,
-Nider, Hayato Ohhashi, OptimisticSide, Harry Porter, Greg Price, Jude
+OptimisticSide, Greg Price, Jude Rich, Ayan Shafqat, Eldar Sehayek,
-Rich, segfault, Ayan Shafqat, Eldar Sehayek, Yongming Shen, Fumiya
+Yongming Shen, Fumiya Shigemitsu, Cam Tenny, tyfkda, Warren Toomey,
-Shigemitsu, Cam Tenny, tyfkda, Warren Toomey, Stephen Tu, Rafael Ubal,
+Stephen Tu, Rafael Ubal, Amane Uehara, Pablo Ventura, Xi Wang, Keiichi
-Amane Uehara, Pablo Ventura, Xi Wang, WaheedHafez, Keiichi Watanabe,
+Watanabe, Nicolas Wolovick, wxdao, Grant Wu, Jindong Zhang, Icenowy
-Nicolas Wolovick, wxdao, Grant Wu, Jindong Zhang, Icenowy Zheng,
+Zheng, ZhUyU1997, and Zou Chang Wei.
-ZhUyU1997, and Zou Chang Wei.
-
 
 The code in the files that constitute xv6 is
-Copyright 2006-2022 Frans Kaashoek, Robert Morris, and Russ Cox.
+Copyright 2006-2020 Frans Kaashoek, Robert Morris, and Russ Cox.
 
 ERROR REPORTS
 
 Please send errors and suggestions to Frans Kaashoek and Robert Morris
 (kaashoek,rtm@mit.edu).  The main purpose of xv6 is as a teaching
-operating system for MIT's 6.1810, so we are more interested in
+operating system for MIT's 6.S081, so we are more interested in
 simplifications and clarifications than new features.
 
 BUILDING AND RUNNING XV6

conf/lab.mk

@@ -1 +1 @@
-LAB=net
+LAB=util

grade-lab-net

@@ -1,43 +0,0 @@
-#!/usr/bin/env python3
-
-import re
-import subprocess
-from gradelib import *
-
-r = Runner(save("xv6.out"))
-
-@test(0, "running nettests")
-def test_nettest():
-    server = subprocess.Popen(["make", "server"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-    r.run_qemu(shell_script([
-        'nettests'
-    ]), timeout=30)
-    server.terminate()
-    server.communicate()
-
-@test(40, "nettest: ping", parent=test_nettest)
-def test_nettest_():
-    r.match('^testing ping: OK$')
-
-@test(20, "nettest: single process", parent=test_nettest)
-def test_nettest_():
-    r.match('^testing single-process pings: OK$')
-
-@test(20, "nettest: multi-process", parent=test_nettest)
-def test_nettest_fork_test():
-    r.match('^testing multi-process pings: OK$')
-
-@test(19, "nettest: DNS", parent=test_nettest)
-def test_nettest_dns_test():
-    r.match('^DNS OK$')
-
-#@test(10, "answers-net.txt")
-#def test_answers():
-#    # just a simple sanity check, will be graded manually
-#    check_answers("answers-net.txt")
-
-@test(1, "time")
-def test_time():
-    check_time()
-
-run_tests()

grade-lab-util

@@ -0,0 +1,86 @@
+#!/usr/bin/env python3
+
+import re
+from gradelib import *
+
+r = Runner(save("xv6.out"))
+
+@test(5, "sleep, no arguments")
+def test_sleep_no_args():
+    r.run_qemu(shell_script([
+        'sleep'
+    ]))
+    r.match(no=["exec .* failed", "$ sleep\n$"])
+
+@test(5, "sleep, returns")
+def test_sleep_no_args():
+    r.run_qemu(shell_script([
+        'sleep',
+        'echo OK'
+    ]))
+    r.match('^OK$', no=["exec .* failed", "$ sleep\n$"])
+
+@test(10, "sleep, makes syscall")
+def test_sleep():
+    r.run_qemu(shell_script([
+        'sleep 10',
+        'echo FAIL'
+    ]), stop_breakpoint('sys_sleep'))
+    r.match('\\$ sleep 10', no=['FAIL'])
+
+@test(20, "pingpong")
+def test_pingpong():
+    r.run_qemu(shell_script([
+        'pingpong', 'echo OK'
+    ]))
+    r.match('^\\d+: received ping$', '^\\d+: received pong$', '^OK$')
+
+@test(20, "primes")
+def test_primes():
+    r.run_qemu(shell_script([
+        'primes', 'echo OK'
+    ]))
+    args = ['prime %d' % i for i in [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31]]
+    args.append('^OK$')
+    r.match(*args)
+
+@test(10, "find, in current directory")
+def test_find_curdir():
+    fn = random_str()
+    r.run_qemu(shell_script([
+        'echo > %s' % fn,
+        'find . %s' % fn
+    ]))
+    r.match('./%s' % fn)
+
+@test(10, "find, recursive")
+def test_find_recursive():
+    needle = random_str()
+    dirs = [random_str() for _ in range(3)]
+    r.run_qemu(shell_script([
+        'mkdir %s' % dirs[0],
+        'echo > %s/%s' % (dirs[0], needle),
+        'mkdir %s/%s' % (dirs[0], dirs[1]),
+        'echo > %s/%s/%s' % (dirs[0], dirs[1], needle),
+        'mkdir %s' % dirs[2],
+        'echo > %s/%s' % (dirs[2], needle),
+        'find . %s' % needle
+    ]))
+    r.match('./%s/%s' % (dirs[0], needle),
+            './%s/%s/%s' % (dirs[0], dirs[1], needle),
+            './%s/%s' % (dirs[2], needle))
+
+@test(19, "xargs")
+def test_xargs():
+    r.run_qemu(shell_script([
+        'sh < xargstest.sh',
+        'echo DONE',
+    ], 'DONE'))
+    matches = re.findall("hello", r.qemu.output)
+    assert_equal(len(matches), 3, "Number of appearances of 'hello'")
+
+@test(1, "time")
+def test_time():
+    check_time()
+    
+run_tests()

kernel/defs.h

@@ -8,10 +8,6 @@ struct spinlock;
 struct sleeplock;
 struct stat;
 struct superblock;
-#ifdef LAB_NET
-struct mbuf;
-struct sock;
-#endif
 
 // bio.c
 void            binit(void);
@@ -121,11 +117,6 @@ void            initlock(struct spinlock*, char*);
 void            release(struct spinlock*);
 void            push_off(void);
 void            pop_off(void);
-uint64          lockfree_read8(uint64 *addr);
-int             lockfree_read4(int *addr);
-#ifdef LAB_LOCK
-void            freelock(struct spinlock*);
-#endif
 
 // sleeplock.c
 void            acquiresleep(struct sleeplock*);
@@ -196,44 +187,3 @@ void            virtio_disk_intr(void);
 
 // number of elements in fixed-size array
 #define NELEM(x) (sizeof(x)/sizeof((x)[0]))
-
-
-
-#ifdef LAB_PGTBL
-// vmcopyin.c
-int             copyin_new(pagetable_t, char *, uint64, uint64);
-int             copyinstr_new(pagetable_t, char *, uint64, uint64);
-#endif
-
-// stats.c
-void            statsinit(void);
-void            statsinc(void);
-
-// sprintf.c
-int             snprintf(char*, int, char*, ...);
-
-#ifdef KCSAN
-void            kcsaninit();
-#endif
-
-#ifdef LAB_NET
-// pci.c
-void            pci_init();
-
-// e1000.c
-void            e1000_init(uint32 *);
-void            e1000_intr(void);
-int             e1000_transmit(struct mbuf*);
-
-// net.c
-void            net_rx(struct mbuf*);
-void            net_tx_udp(struct mbuf*, uint32, uint16, uint16);
-
-// sysnet.c
-void            sockinit(void);
-int             sockalloc(struct file **, uint32, uint16, uint16);
-void            sockclose(struct sock *);
-int             sockread(struct sock *, uint64, int);
-int             sockwrite(struct sock *, uint64, int);
-void            sockrecvudp(struct mbuf*, uint32, uint16, uint16);
-#endif

kernel/e1000.c

@@ -1,162 +0,0 @@
-#include "types.h"
-#include "param.h"
-#include "memlayout.h"
-#include "riscv.h"
-#include "spinlock.h"
-#include "proc.h"
-#include "defs.h"
-#include "e1000_dev.h"
-#include "net.h"
-
-#define TX_RING_SIZE 16
-static struct tx_desc tx_ring[TX_RING_SIZE] __attribute__((aligned(16)));
-static struct mbuf *tx_mbufs[TX_RING_SIZE];
-
-#define RX_RING_SIZE 16
-static struct rx_desc rx_ring[RX_RING_SIZE] __attribute__((aligned(16)));
-static struct mbuf *rx_mbufs[RX_RING_SIZE];
-
-// remember where the e1000's registers live.
-static volatile uint32 *regs;
-
-struct spinlock e1000_lock;
-
-// called by pci_init().
-// xregs is the memory address at which the
-// e1000's registers are mapped.
-void
-e1000_init(uint32 *xregs)
-{
-  int i;
-
-  initlock(&e1000_lock, "e1000");
-
-  regs = xregs;
-
-  // Reset the device
-  regs[E1000_IMS] = 0; // disable interrupts
-  regs[E1000_CTL] |= E1000_CTL_RST;
-  regs[E1000_IMS] = 0; // redisable interrupts
-  __sync_synchronize();
-
-  // [E1000 14.5] Transmit initialization
-  memset(tx_ring, 0, sizeof(tx_ring));
-  for (i = 0; i < TX_RING_SIZE; i++) {
-    tx_ring[i].status = E1000_TXD_STAT_DD;
-    tx_mbufs[i] = 0;
-  }
-  regs[E1000_TDBAL] = (uint64) tx_ring;
-  if(sizeof(tx_ring) % 128 != 0)
-    panic("e1000");
-  regs[E1000_TDLEN] = sizeof(tx_ring);
-  regs[E1000_TDH] = regs[E1000_TDT] = 0;
-  
-  // [E1000 14.4] Receive initialization
-  memset(rx_ring, 0, sizeof(rx_ring));
-  for (i = 0; i < RX_RING_SIZE; i++) {
-    rx_mbufs[i] = mbufalloc(0);
-    if (!rx_mbufs[i])
-      panic("e1000");
-    rx_ring[i].addr = (uint64) rx_mbufs[i]->head;
-  }
-  regs[E1000_RDBAL] = (uint64) rx_ring;
-  if(sizeof(rx_ring) % 128 != 0)
-    panic("e1000");
-  regs[E1000_RDH] = 0;
-  regs[E1000_RDT] = RX_RING_SIZE - 1;
-  regs[E1000_RDLEN] = sizeof(rx_ring);
-
-  // filter by qemu's MAC address, 52:54:00:12:34:56
-  regs[E1000_RA] = 0x12005452;
-  regs[E1000_RA+1] = 0x5634 | (1<<31);
-  // multicast table
-  for (int i = 0; i < 4096/32; i++)
-    regs[E1000_MTA + i] = 0;
-
-  // transmitter control bits.
-  regs[E1000_TCTL] = E1000_TCTL_EN |  // enable
-    E1000_TCTL_PSP |                  // pad short packets
-    (0x10 << E1000_TCTL_CT_SHIFT) |   // collision stuff
-    (0x40 << E1000_TCTL_COLD_SHIFT);
-  regs[E1000_TIPG] = 10 | (8<<10) | (6<<20); // inter-pkt gap
-
-  // receiver control bits.
-  regs[E1000_RCTL] = E1000_RCTL_EN | // enable receiver
-    E1000_RCTL_BAM |                 // enable broadcast
-    E1000_RCTL_SZ_2048 |             // 2048-byte rx buffers
-    E1000_RCTL_SECRC;                // strip CRC
-  
-  // ask e1000 for receive interrupts.
-  regs[E1000_RDTR] = 0; // interrupt after every received packet (no timer)
-  regs[E1000_RADV] = 0; // interrupt after every packet (no timer)
-  regs[E1000_IMS] = (1 << 7); // RXDW -- Receiver Descriptor Write Back
-}
-
-int
-e1000_transmit(struct mbuf *m)
-{
-  //
-  // Your code here.
-  //
-  // the mbuf contains an ethernet frame; program it into
-  // the TX descriptor ring so that the e1000 sends it. Stash
-  // a pointer so that it can be freed after sending.
-  //
-
-  acquire(&e1000_lock);
-  int tdt = regs[E1000_TDT];
-  if (!(tx_ring[tdt].status & E1000_TXD_STAT_DD)) {
-    release(&e1000_lock);
-    return -1;
-  }
-  if (tx_mbufs[tdt]) {
-    mbuffree(tx_mbufs[tdt]);
-    tx_mbufs[tdt] = 0;
-  }
-  tx_mbufs[tdt] = m;
-  tx_ring[tdt].addr = (uint64)m->head;
-  tx_ring[tdt].length = m->len;
-  tx_ring[tdt].cmd = E1000_TXD_CMD_RS | E1000_TXD_CMD_EOP;
-  regs[E1000_TDT] = (tdt + 1) % TX_RING_SIZE;
-  release(&e1000_lock);
-  return 0;
-}
-
-static void
-e1000_recv(void)
-{
-  //
-  // Your code here.
-  //
-  // Check for packets that have arrived from the e1000
-  // Create and deliver an mbuf for each packet (using net_rx()).
-  //
-  acquire(&e1000_lock);
-  int rdt = regs[E1000_RDT];
-  rdt = (rdt + 1) % RX_RING_SIZE;
-  while (rx_ring[rdt].status & E1000_RXD_STAT_DD)
-  {
-    if (!holding(&e1000_lock)) acquire(&e1000_lock);
-    rx_mbufs[rdt]->len = rx_ring[rdt].length;
-    struct mbuf* m = rx_mbufs[rdt];
-    rx_mbufs[rdt] = mbufalloc(0);
-    if (!rx_mbufs[rdt]) panic("e1000 recv");
-    rx_ring[rdt].addr = (uint64)rx_mbufs[rdt]->head;
-    rx_ring[rdt].status = 0;
-    regs[E1000_RDT] = rdt;
-    rdt = (rdt + 1) % RX_RING_SIZE;
-    release(&e1000_lock);
-    net_rx(m);
-  }
-}
-
-void
-e1000_intr(void)
-{
-  // tell the e1000 we've seen this interrupt;
-  // without this the e1000 won't raise any
-  // further interrupts.
-  regs[E1000_ICR] = 0xffffffff;
-
-  e1000_recv();
-}

kernel/e1000_dev.h

@@ -1,125 +0,0 @@
-//
-// E1000 hardware definitions: registers and DMA ring format.
-// from the Intel 82540EP/EM &c manual.
-//
-
-/* Registers */
-#define E1000_CTL      (0x00000/4)  /* Device Control Register - RW */
-#define E1000_ICR      (0x000C0/4)  /* Interrupt Cause Read - R */
-#define E1000_IMS      (0x000D0/4)  /* Interrupt Mask Set - RW */
-#define E1000_RCTL     (0x00100/4)  /* RX Control - RW */
-#define E1000_TCTL     (0x00400/4)  /* TX Control - RW */
-#define E1000_TIPG     (0x00410/4)  /* TX Inter-packet gap -RW */
-#define E1000_RDBAL    (0x02800/4)  /* RX Descriptor Base Address Low - RW */
-#define E1000_RDTR     (0x02820/4)  /* RX Delay Timer */
-#define E1000_RADV     (0x0282C/4)  /* RX Interrupt Absolute Delay Timer */
-#define E1000_RDH      (0x02810/4)  /* RX Descriptor Head - RW */
-#define E1000_RDT      (0x02818/4)  /* RX Descriptor Tail - RW */
-#define E1000_RDLEN    (0x02808/4)  /* RX Descriptor Length - RW */
-#define E1000_RSRPD    (0x02C00/4)  /* RX Small Packet Detect Interrupt */
-#define E1000_TDBAL    (0x03800/4)  /* TX Descriptor Base Address Low - RW */
-#define E1000_TDLEN    (0x03808/4)  /* TX Descriptor Length - RW */
-#define E1000_TDH      (0x03810/4)  /* TX Descriptor Head - RW */
-#define E1000_TDT      (0x03818/4)  /* TX Descripotr Tail - RW */
-#define E1000_MTA      (0x05200/4)  /* Multicast Table Array - RW Array */
-#define E1000_RA       (0x05400/4)  /* Receive Address - RW Array */
-
-/* Device Control */
-#define E1000_CTL_SLU     0x00000040    /* set link up */
-#define E1000_CTL_FRCSPD  0x00000800    /* force speed */
-#define E1000_CTL_FRCDPLX 0x00001000    /* force duplex */
-#define E1000_CTL_RST     0x00400000    /* full reset */
-
-/* Transmit Control */
-#define E1000_TCTL_RST    0x00000001    /* software reset */
-#define E1000_TCTL_EN     0x00000002    /* enable tx */
-#define E1000_TCTL_BCE    0x00000004    /* busy check enable */
-#define E1000_TCTL_PSP    0x00000008    /* pad short packets */
-#define E1000_TCTL_CT     0x00000ff0    /* collision threshold */
-#define E1000_TCTL_CT_SHIFT 4
-#define E1000_TCTL_COLD   0x003ff000    /* collision distance */
-#define E1000_TCTL_COLD_SHIFT 12
-#define E1000_TCTL_SWXOFF 0x00400000    /* SW Xoff transmission */
-#define E1000_TCTL_PBE    0x00800000    /* Packet Burst Enable */
-#define E1000_TCTL_RTLC   0x01000000    /* Re-transmit on late collision */
-#define E1000_TCTL_NRTU   0x02000000    /* No Re-transmit on underrun */
-#define E1000_TCTL_MULR   0x10000000    /* Multiple request support */
-
-/* Receive Control */
-#define E1000_RCTL_RST            0x00000001    /* Software reset */
-#define E1000_RCTL_EN             0x00000002    /* enable */
-#define E1000_RCTL_SBP            0x00000004    /* store bad packet */
-#define E1000_RCTL_UPE            0x00000008    /* unicast promiscuous enable */
-#define E1000_RCTL_MPE            0x00000010    /* multicast promiscuous enab */
-#define E1000_RCTL_LPE            0x00000020    /* long packet enable */
-#define E1000_RCTL_LBM_NO         0x00000000    /* no loopback mode */
-#define E1000_RCTL_LBM_MAC        0x00000040    /* MAC loopback mode */
-#define E1000_RCTL_LBM_SLP        0x00000080    /* serial link loopback mode */
-#define E1000_RCTL_LBM_TCVR       0x000000C0    /* tcvr loopback mode */
-#define E1000_RCTL_DTYP_MASK      0x00000C00    /* Descriptor type mask */
-#define E1000_RCTL_DTYP_PS        0x00000400    /* Packet Split descriptor */
-#define E1000_RCTL_RDMTS_HALF     0x00000000    /* rx desc min threshold size */
-#define E1000_RCTL_RDMTS_QUAT     0x00000100    /* rx desc min threshold size */
-#define E1000_RCTL_RDMTS_EIGTH    0x00000200    /* rx desc min threshold size */
-#define E1000_RCTL_MO_SHIFT       12            /* multicast offset shift */
-#define E1000_RCTL_MO_0           0x00000000    /* multicast offset 11:0 */
-#define E1000_RCTL_MO_1           0x00001000    /* multicast offset 12:1 */
-#define E1000_RCTL_MO_2           0x00002000    /* multicast offset 13:2 */
-#define E1000_RCTL_MO_3           0x00003000    /* multicast offset 15:4 */
-#define E1000_RCTL_MDR            0x00004000    /* multicast desc ring 0 */
-#define E1000_RCTL_BAM            0x00008000    /* broadcast enable */
-/* these buffer sizes are valid if E1000_RCTL_BSEX is 0 */
-#define E1000_RCTL_SZ_2048        0x00000000    /* rx buffer size 2048 */
-#define E1000_RCTL_SZ_1024        0x00010000    /* rx buffer size 1024 */
-#define E1000_RCTL_SZ_512         0x00020000    /* rx buffer size 512 */
-#define E1000_RCTL_SZ_256         0x00030000    /* rx buffer size 256 */
-/* these buffer sizes are valid if E1000_RCTL_BSEX is 1 */
-#define E1000_RCTL_SZ_16384       0x00010000    /* rx buffer size 16384 */
-#define E1000_RCTL_SZ_8192        0x00020000    /* rx buffer size 8192 */
-#define E1000_RCTL_SZ_4096        0x00030000    /* rx buffer size 4096 */
-#define E1000_RCTL_VFE            0x00040000    /* vlan filter enable */
-#define E1000_RCTL_CFIEN          0x00080000    /* canonical form enable */
-#define E1000_RCTL_CFI            0x00100000    /* canonical form indicator */
-#define E1000_RCTL_DPF            0x00400000    /* discard pause frames */
-#define E1000_RCTL_PMCF           0x00800000    /* pass MAC control frames */
-#define E1000_RCTL_BSEX           0x02000000    /* Buffer size extension */
-#define E1000_RCTL_SECRC          0x04000000    /* Strip Ethernet CRC */
-#define E1000_RCTL_FLXBUF_MASK    0x78000000    /* Flexible buffer size */
-#define E1000_RCTL_FLXBUF_SHIFT   27            /* Flexible buffer shift */
-
-#define DATA_MAX 1518
-
-/* Transmit Descriptor command definitions [E1000 3.3.3.1] */
-#define E1000_TXD_CMD_EOP    0x01 /* End of Packet */
-#define E1000_TXD_CMD_RS     0x08 /* Report Status */
-
-/* Transmit Descriptor status definitions [E1000 3.3.3.2] */
-#define E1000_TXD_STAT_DD    0x00000001 /* Descriptor Done */
-
-// [E1000 3.3.3]
-struct tx_desc
-{
-  uint64 addr;
-  uint16 length;
-  uint8 cso;
-  uint8 cmd;
-  uint8 status;
-  uint8 css;
-  uint16 special;
-};
-
-/* Receive Descriptor bit definitions [E1000 3.2.3.1] */
-#define E1000_RXD_STAT_DD       0x01    /* Descriptor Done */
-#define E1000_RXD_STAT_EOP      0x02    /* End of Packet */
-
-// [E1000 3.2.3]
-struct rx_desc
-{
-  uint64 addr;       /* Address of the descriptor's data buffer */
-  uint16 length;     /* Length of data DMAed into data buffer */
-  uint16 csum;       /* Packet checksum */
-  uint8 status;      /* Descriptor status */
-  uint8 errors;      /* Descriptor Errors */
-  uint16 special;
-};
-

kernel/file.c

@@ -80,11 +80,6 @@ fileclose(struct file *f)
     iput(ff.ip);
     end_op();
   }
-#ifdef LAB_NET
-  else if(ff.type == FD_SOCK){
-    sockclose(ff.sock);
-  }
-#endif
 }
 
 // Get metadata about file f.
@@ -127,13 +122,7 @@ fileread(struct file *f, uint64 addr, int n)
     if((r = readi(f->ip, 1, addr, f->off, n)) > 0)
       f->off += r;
     iunlock(f->ip);
-  }
+  } else {
-#ifdef LAB_NET
-  else if(f->type == FD_SOCK){
-    r = sockread(f->sock, addr, n);
-  }
-#endif
-  else {
     panic("fileread");
   }
 
@@ -184,13 +173,7 @@ filewrite(struct file *f, uint64 addr, int n)
       i += r;
     }
     ret = (i == n ? n : -1);
-  }
+  } else {
-#ifdef LAB_NET
-  else if(f->type == FD_SOCK){
-    ret = sockwrite(f->sock, addr, n);
-  }
-#endif
-  else {
     panic("filewrite");
   }
 

kernel/file.h

@@ -1,17 +1,10 @@
 struct file {
-#ifdef LAB_NET
-  enum { FD_NONE, FD_PIPE, FD_INODE, FD_DEVICE, FD_SOCK } type;
-#else
   enum { FD_NONE, FD_PIPE, FD_INODE, FD_DEVICE } type;
-#endif
   int ref; // reference count
   char readable;
   char writable;
   struct pipe *pipe; // FD_PIPE
   struct inode *ip;  // FD_INODE and FD_DEVICE
-#ifdef LAB_NET
-  struct sock *sock; // FD_SOCK
-#endif
   uint off;          // FD_INODE
   short major;       // FD_DEVICE
 };
@@ -45,4 +38,3 @@ struct devsw {
 extern struct devsw devsw[];
 
 #define CONSOLE 1
-#define STATS   2

kernel/main.c

@@ -12,9 +12,6 @@ main()
 {
   if(cpuid() == 0){
     consoleinit();
-#if defined(LAB_LOCK)
-    statsinit();
-#endif
     printfinit();
     printf("\n");
     printf("xv6 kernel is booting\n");
@@ -31,18 +28,11 @@ main()
     iinit();         // inode table
     fileinit();      // file table
     virtio_disk_init(); // emulated hard disk
-#ifdef LAB_NET
-    pci_init();
-    sockinit();
-#endif    
     userinit();      // first user process
-#ifdef KCSAN
-    kcsaninit();
-#endif
     __sync_synchronize();
     started = 1;
   } else {
-    while(lockfree_read4((int *) &started) == 0)
+    while(started == 0)
       ;
     __sync_synchronize();
     printf("hart %d starting\n", cpuid());

kernel/memlayout.h

@@ -25,10 +25,6 @@
 #define VIRTIO0 0x10001000
 #define VIRTIO0_IRQ 1
 
-#ifdef LAB_NET
-#define E1000_IRQ 33
-#endif
-
 // core local interruptor (CLINT), which contains the timer.
 #define CLINT 0x2000000L
 #define CLINT_MTIMECMP(hartid) (CLINT + 0x4000 + 8*(hartid))
@@ -57,7 +53,7 @@
 
 // map kernel stacks beneath the trampoline,
 // each surrounded by invalid guard pages.
-#define KSTACK(p) (TRAMPOLINE - (p)*2*PGSIZE - 3*PGSIZE)
+#define KSTACK(p) (TRAMPOLINE - ((p)+1)* 2*PGSIZE)
 
 // User memory layout.
 // Address zero first:
@@ -66,14 +62,6 @@
 //   fixed-size stack
 //   expandable heap
 //   ...
-//   USYSCALL (shared with kernel)
 //   TRAPFRAME (p->trapframe, used by the trampoline)
 //   TRAMPOLINE (the same page as in the kernel)
 #define TRAPFRAME (TRAMPOLINE - PGSIZE)
-#ifdef LAB_PGTBL
-#define USYSCALL (TRAPFRAME - PGSIZE)
-
-struct usyscall {
-  int pid;  // Process ID
-};
-#endif

kernel/net.c

@@ -1,374 +0,0 @@
-//
-// networking protocol support (IP, UDP, ARP, etc.).
-//
-
-#include "types.h"
-#include "param.h"
-#include "memlayout.h"
-#include "riscv.h"
-#include "spinlock.h"
-#include "proc.h"
-#include "net.h"
-#include "defs.h"
-
-static uint32 local_ip = MAKE_IP_ADDR(10, 0, 2, 15); // qemu's idea of the guest IP
-static uint8 local_mac[ETHADDR_LEN] = { 0x52, 0x54, 0x00, 0x12, 0x34, 0x56 };
-static uint8 broadcast_mac[ETHADDR_LEN] = { 0xFF, 0XFF, 0XFF, 0XFF, 0XFF, 0XFF };
-
-// Strips data from the start of the buffer and returns a pointer to it.
-// Returns 0 if less than the full requested length is available.
-char *
-mbufpull(struct mbuf *m, unsigned int len)
-{
-  char *tmp = m->head;
-  if (m->len < len)
-    return 0;
-  m->len -= len;
-  m->head += len;
-  return tmp;
-}
-
-// Prepends data to the beginning of the buffer and returns a pointer to it.
-char *
-mbufpush(struct mbuf *m, unsigned int len)
-{
-  m->head -= len;
-  if (m->head < m->buf)
-    panic("mbufpush");
-  m->len += len;
-  return m->head;
-}
-
-// Appends data to the end of the buffer and returns a pointer to it.
-char *
-mbufput(struct mbuf *m, unsigned int len)
-{
-  char *tmp = m->head + m->len;
-  m->len += len;
-  if (m->len > MBUF_SIZE)
-    panic("mbufput");
-  return tmp;
-}
-
-// Strips data from the end of the buffer and returns a pointer to it.
-// Returns 0 if less than the full requested length is available.
-char *
-mbuftrim(struct mbuf *m, unsigned int len)
-{
-  if (len > m->len)
-    return 0;
-  m->len -= len;
-  return m->head + m->len;
-}
-
-// Allocates a packet buffer.
-struct mbuf *
-mbufalloc(unsigned int headroom)
-{
-  struct mbuf *m;
- 
-  if (headroom > MBUF_SIZE)
-    return 0;
-  m = kalloc();
-  if (m == 0)
-    return 0;
-  m->next = 0;
-  m->head = (char *)m->buf + headroom;
-  m->len = 0;
-  memset(m->buf, 0, sizeof(m->buf));
-  return m;
-}
-
-// Frees a packet buffer.
-void
-mbuffree(struct mbuf *m)
-{
-  kfree(m);
-}
-
-// Pushes an mbuf to the end of the queue.
-void
-mbufq_pushtail(struct mbufq *q, struct mbuf *m)
-{
-  m->next = 0;
-  if (!q->head){
-    q->head = q->tail = m;
-    return;
-  }
-  q->tail->next = m;
-  q->tail = m;
-}
-
-// Pops an mbuf from the start of the queue.
-struct mbuf *
-mbufq_pophead(struct mbufq *q)
-{
-  struct mbuf *head = q->head;
-  if (!head)
-    return 0;
-  q->head = head->next;
-  return head;
-}
-
-// Returns one (nonzero) if the queue is empty.
-int
-mbufq_empty(struct mbufq *q)
-{
-  return q->head == 0;
-}
-
-// Intializes a queue of mbufs.
-void
-mbufq_init(struct mbufq *q)
-{
-  q->head = 0;
-}
-
-// This code is lifted from FreeBSD's ping.c, and is copyright by the Regents
-// of the University of California.
-static unsigned short
-in_cksum(const unsigned char *addr, int len)
-{
-  int nleft = len;
-  const unsigned short *w = (const unsigned short *)addr;
-  unsigned int sum = 0;
-  unsigned short answer = 0;
-
-  /*
-   * Our algorithm is simple, using a 32 bit accumulator (sum), we add
-   * sequential 16 bit words to it, and at the end, fold back all the
-   * carry bits from the top 16 bits into the lower 16 bits.
-   */
-  while (nleft > 1)  {
-    sum += *w++;
-    nleft -= 2;
-  }
-
-  /* mop up an odd byte, if necessary */
-  if (nleft == 1) {
-    *(unsigned char *)(&answer) = *(const unsigned char *)w;
-    sum += answer;
-  }
-
-  /* add back carry outs from top 16 bits to low 16 bits */
-  sum = (sum & 0xffff) + (sum >> 16);
-  sum += (sum >> 16);
-  /* guaranteed now that the lower 16 bits of sum are correct */
-
-  answer = ~sum; /* truncate to 16 bits */
-  return answer;
-}
-
-// sends an ethernet packet
-static void
-net_tx_eth(struct mbuf *m, uint16 ethtype)
-{
-  struct eth *ethhdr;
-
-  ethhdr = mbufpushhdr(m, *ethhdr);
-  memmove(ethhdr->shost, local_mac, ETHADDR_LEN);
-  // In a real networking stack, dhost would be set to the address discovered
-  // through ARP. Because we don't support enough of the ARP protocol, set it
-  // to broadcast instead.
-  memmove(ethhdr->dhost, broadcast_mac, ETHADDR_LEN);
-  ethhdr->type = htons(ethtype);
-  if (e1000_transmit(m)) {
-    mbuffree(m);
-  }
-}
-
-// sends an IP packet
-static void
-net_tx_ip(struct mbuf *m, uint8 proto, uint32 dip)
-{
-  struct ip *iphdr;
-
-  // push the IP header
-  iphdr = mbufpushhdr(m, *iphdr);
-  memset(iphdr, 0, sizeof(*iphdr));
-  iphdr->ip_vhl = (4 << 4) | (20 >> 2);
-  iphdr->ip_p = proto;
-  iphdr->ip_src = htonl(local_ip);
-  iphdr->ip_dst = htonl(dip);
-  iphdr->ip_len = htons(m->len);
-  iphdr->ip_ttl = 100;
-  iphdr->ip_sum = in_cksum((unsigned char *)iphdr, sizeof(*iphdr));
-
-  // now on to the ethernet layer
-  net_tx_eth(m, ETHTYPE_IP);
-}
-
-// sends a UDP packet
-void
-net_tx_udp(struct mbuf *m, uint32 dip,
-           uint16 sport, uint16 dport)
-{
-  struct udp *udphdr;
-
-  // put the UDP header
-  udphdr = mbufpushhdr(m, *udphdr);
-  udphdr->sport = htons(sport);
-  udphdr->dport = htons(dport);
-  udphdr->ulen = htons(m->len);
-  udphdr->sum = 0; // zero means no checksum is provided
-
-  // now on to the IP layer
-  net_tx_ip(m, IPPROTO_UDP, dip);
-}
-
-// sends an ARP packet
-static int
-net_tx_arp(uint16 op, uint8 dmac[ETHADDR_LEN], uint32 dip)
-{
-  struct mbuf *m;
-  struct arp *arphdr;
-
-  m = mbufalloc(MBUF_DEFAULT_HEADROOM);
-  if (!m)
-    return -1;
-
-  // generic part of ARP header
-  arphdr = mbufputhdr(m, *arphdr);
-  arphdr->hrd = htons(ARP_HRD_ETHER);
-  arphdr->pro = htons(ETHTYPE_IP);
-  arphdr->hln = ETHADDR_LEN;
-  arphdr->pln = sizeof(uint32);
-  arphdr->op = htons(op);
-
-  // ethernet + IP part of ARP header
-  memmove(arphdr->sha, local_mac, ETHADDR_LEN);
-  arphdr->sip = htonl(local_ip);
-  memmove(arphdr->tha, dmac, ETHADDR_LEN);
-  arphdr->tip = htonl(dip);
-
-  // header is ready, send the packet
-  net_tx_eth(m, ETHTYPE_ARP);
-  return 0;
-}
-
-// receives an ARP packet
-static void
-net_rx_arp(struct mbuf *m)
-{
-  struct arp *arphdr;
-  uint8 smac[ETHADDR_LEN];
-  uint32 sip, tip;
-
-  arphdr = mbufpullhdr(m, *arphdr);
-  if (!arphdr)
-    goto done;
-
-  // validate the ARP header
-  if (ntohs(arphdr->hrd) != ARP_HRD_ETHER ||
-      ntohs(arphdr->pro) != ETHTYPE_IP ||
-      arphdr->hln != ETHADDR_LEN ||
-      arphdr->pln != sizeof(uint32)) {
-    goto done;
-  }
-
-  // only requests are supported so far
-  // check if our IP was solicited
-  tip = ntohl(arphdr->tip); // target IP address
-  if (ntohs(arphdr->op) != ARP_OP_REQUEST || tip != local_ip)
-    goto done;
-
-  // handle the ARP request
-  memmove(smac, arphdr->sha, ETHADDR_LEN); // sender's ethernet address
-  sip = ntohl(arphdr->sip); // sender's IP address (qemu's slirp)
-  net_tx_arp(ARP_OP_REPLY, smac, sip);
-
-done:
-  mbuffree(m);
-}
-
-// receives a UDP packet
-static void
-net_rx_udp(struct mbuf *m, uint16 len, struct ip *iphdr)
-{
-  struct udp *udphdr;
-  uint32 sip;
-  uint16 sport, dport;
-
-
-  udphdr = mbufpullhdr(m, *udphdr);
-  if (!udphdr)
-    goto fail;
-
-  // TODO: validate UDP checksum
-
-  // validate lengths reported in headers
-  if (ntohs(udphdr->ulen) != len)
-    goto fail;
-  len -= sizeof(*udphdr);
-  if (len > m->len)
-    goto fail;
-  // minimum packet size could be larger than the payload
-  mbuftrim(m, m->len - len);
-
-  // parse the necessary fields
-  sip = ntohl(iphdr->ip_src);
-  sport = ntohs(udphdr->sport);
-  dport = ntohs(udphdr->dport);
-  sockrecvudp(m, sip, dport, sport);
-  return;
-
-fail:
-  mbuffree(m);
-}
-
-// receives an IP packet
-static void
-net_rx_ip(struct mbuf *m)
-{
-  struct ip *iphdr;
-  uint16 len;
-
-  iphdr = mbufpullhdr(m, *iphdr);
-  if (!iphdr)
-	  goto fail;
-
-  // check IP version and header len
-  if (iphdr->ip_vhl != ((4 << 4) | (20 >> 2)))
-    goto fail;
-  // validate IP checksum
-  if (in_cksum((unsigned char *)iphdr, sizeof(*iphdr)))
-    goto fail;
-  // can't support fragmented IP packets
-  if (htons(iphdr->ip_off) != 0)
-    goto fail;
-  // is the packet addressed to us?
-  if (htonl(iphdr->ip_dst) != local_ip)
-    goto fail;
-  // can only support UDP
-  if (iphdr->ip_p != IPPROTO_UDP)
-    goto fail;
-
-  len = ntohs(iphdr->ip_len) - sizeof(*iphdr);
-  net_rx_udp(m, len, iphdr);
-  return;
-
-fail:
-  mbuffree(m);
-}
-
-// called by e1000 driver's interrupt handler to deliver a packet to the
-// networking stack
-void net_rx(struct mbuf *m)
-{
-  struct eth *ethhdr;
-  uint16 type;
-
-  ethhdr = mbufpullhdr(m, *ethhdr);
-  if (!ethhdr) {
-    mbuffree(m);
-    return;
-  }
-
-  type = ntohs(ethhdr->type);
-  if (type == ETHTYPE_IP)
-    net_rx_ip(m);
-  else if (type == ETHTYPE_ARP)
-    net_rx_arp(m);
-  else
-    mbuffree(m);
-}

kernel/net.h

@@ -1,173 +0,0 @@
-//
-// packet buffer management
-//
-
-#define MBUF_SIZE              2048
-#define MBUF_DEFAULT_HEADROOM  128
-
-struct mbuf {
-  struct mbuf  *next; // the next mbuf in the chain
-  char         *head; // the current start position of the buffer
-  unsigned int len;   // the length of the buffer
-  char         buf[MBUF_SIZE]; // the backing store
-};
-
-char *mbufpull(struct mbuf *m, unsigned int len);
-char *mbufpush(struct mbuf *m, unsigned int len);
-char *mbufput(struct mbuf *m, unsigned int len);
-char *mbuftrim(struct mbuf *m, unsigned int len);
-
-// The above functions manipulate the size and position of the buffer:
-//            <- push            <- trim
-//             -> pull            -> put
-// [-headroom-][------buffer------][-tailroom-]
-// |----------------MBUF_SIZE-----------------|
-//
-// These marcos automatically typecast and determine the size of header structs.
-// In most situations you should use these instead of the raw ops above.
-#define mbufpullhdr(mbuf, hdr) (typeof(hdr)*)mbufpull(mbuf, sizeof(hdr))
-#define mbufpushhdr(mbuf, hdr) (typeof(hdr)*)mbufpush(mbuf, sizeof(hdr))
-#define mbufputhdr(mbuf, hdr) (typeof(hdr)*)mbufput(mbuf, sizeof(hdr))
-#define mbuftrimhdr(mbuf, hdr) (typeof(hdr)*)mbuftrim(mbuf, sizeof(hdr))
-
-struct mbuf *mbufalloc(unsigned int headroom);
-void mbuffree(struct mbuf *m);
-
-struct mbufq {
-  struct mbuf *head;  // the first element in the queue
-  struct mbuf *tail;  // the last element in the queue
-};
-
-void mbufq_pushtail(struct mbufq *q, struct mbuf *m);
-struct mbuf *mbufq_pophead(struct mbufq *q);
-int mbufq_empty(struct mbufq *q);
-void mbufq_init(struct mbufq *q);
-
-
-//
-// endianness support
-//
-
-static inline uint16 bswaps(uint16 val)
-{
-  return (((val & 0x00ffU) << 8) |
-          ((val & 0xff00U) >> 8));
-}
-
-static inline uint32 bswapl(uint32 val)
-{
-  return (((val & 0x000000ffUL) << 24) |
-          ((val & 0x0000ff00UL) << 8) |
-          ((val & 0x00ff0000UL) >> 8) |
-          ((val & 0xff000000UL) >> 24));
-}
-
-// Use these macros to convert network bytes to the native byte order.
-// Note that Risc-V uses little endian while network order is big endian.
-#define ntohs bswaps
-#define ntohl bswapl
-#define htons bswaps
-#define htonl bswapl
-
-
-//
-// useful networking headers
-//
-
-#define ETHADDR_LEN 6
-
-// an Ethernet packet header (start of the packet).
-struct eth {
-  uint8  dhost[ETHADDR_LEN];
-  uint8  shost[ETHADDR_LEN];
-  uint16 type;
-} __attribute__((packed));
-
-#define ETHTYPE_IP  0x0800 // Internet protocol
-#define ETHTYPE_ARP 0x0806 // Address resolution protocol
-
-// an IP packet header (comes after an Ethernet header).
-struct ip {
-  uint8  ip_vhl; // version << 4 | header length >> 2
-  uint8  ip_tos; // type of service
-  uint16 ip_len; // total length
-  uint16 ip_id;  // identification
-  uint16 ip_off; // fragment offset field
-  uint8  ip_ttl; // time to live
-  uint8  ip_p;   // protocol
-  uint16 ip_sum; // checksum
-  uint32 ip_src, ip_dst;
-};
-
-#define IPPROTO_ICMP 1  // Control message protocol
-#define IPPROTO_TCP  6  // Transmission control protocol
-#define IPPROTO_UDP  17 // User datagram protocol
-
-#define MAKE_IP_ADDR(a, b, c, d)           \
-  (((uint32)a << 24) | ((uint32)b << 16) | \
-   ((uint32)c << 8) | (uint32)d)
-
-// a UDP packet header (comes after an IP header).
-struct udp {
-  uint16 sport; // source port
-  uint16 dport; // destination port
-  uint16 ulen;  // length, including udp header, not including IP header
-  uint16 sum;   // checksum
-};
-
-// an ARP packet (comes after an Ethernet header).
-struct arp {
-  uint16 hrd; // format of hardware address
-  uint16 pro; // format of protocol address
-  uint8  hln; // length of hardware address
-  uint8  pln; // length of protocol address
-  uint16 op;  // operation
-
-  char   sha[ETHADDR_LEN]; // sender hardware address
-  uint32 sip;              // sender IP address
-  char   tha[ETHADDR_LEN]; // target hardware address
-  uint32 tip;              // target IP address
-} __attribute__((packed));
-
-#define ARP_HRD_ETHER 1 // Ethernet
-
-enum {
-  ARP_OP_REQUEST = 1, // requests hw addr given protocol addr
-  ARP_OP_REPLY = 2,   // replies a hw addr given protocol addr
-};
-
-// an DNS packet (comes after an UDP header).
-struct dns {
-  uint16 id;  // request ID
-
-  uint8 rd: 1;  // recursion desired
-  uint8 tc: 1;  // truncated
-  uint8 aa: 1;  // authoritive
-  uint8 opcode: 4; 
-  uint8 qr: 1;  // query/response
-  uint8 rcode: 4; // response code
-  uint8 cd: 1;  // checking disabled
-  uint8 ad: 1;  // authenticated data
-  uint8 z:  1;  
-  uint8 ra: 1;  // recursion available
-  
-  uint16 qdcount; // number of question entries
-  uint16 ancount; // number of resource records in answer section
-  uint16 nscount; // number of NS resource records in authority section
-  uint16 arcount; // number of resource records in additional records
-} __attribute__((packed));
-
-struct dns_question {
-  uint16 qtype;
-  uint16 qclass;
-} __attribute__((packed));
-  
-#define ARECORD (0x0001)
-#define QCLASS  (0x0001)
-
-struct dns_data {
-  uint16 type;
-  uint16 class;
-  uint32 ttl;
-  uint16 len;
-} __attribute__((packed));

kernel/pci.c

@@ -1,61 +0,0 @@
-//
-// simple PCI-Express initialization, only
-// works for qemu and its e1000 card.
-//
-
-#include "types.h"
-#include "param.h"
-#include "memlayout.h"
-#include "riscv.h"
-#include "spinlock.h"
-#include "proc.h"
-#include "defs.h"
-
-void
-pci_init()
-{
-  // we'll place the e1000 registers at this address.
-  // vm.c maps this range.
-  uint64 e1000_regs = 0x40000000L;
-
-  // qemu -machine virt puts PCIe config space here.
-  // vm.c maps this range.
-  uint32  *ecam = (uint32 *) 0x30000000L;
-  
-  // look at each possible PCI device on bus 0.
-  for(int dev = 0; dev < 32; dev++){
-    int bus = 0;
-    int func = 0;
-    int offset = 0;
-    uint32 off = (bus << 16) | (dev << 11) | (func << 8) | (offset);
-    volatile uint32 *base = ecam + off;
-    uint32 id = base[0];
-    
-    // 100e:8086 is an e1000
-    if(id == 0x100e8086){
-      // command and status register.
-      // bit 0 : I/O access enable
-      // bit 1 : memory access enable
-      // bit 2 : enable mastering
-      base[1] = 7;
-      __sync_synchronize();
-
-      for(int i = 0; i < 6; i++){
-        uint32 old = base[4+i];
-
-        // writing all 1's to the BAR causes it to be
-        // replaced with its size.
-        base[4+i] = 0xffffffff;
-        __sync_synchronize();
-
-        base[4+i] = old;
-      }
-
-      // tell the e1000 to reveal its registers at
-      // physical address 0x40000000.
-      base[4+0] = e1000_regs;
-
-      e1000_init((uint32*)e1000_regs);
-    }
-  }
-}

kernel/plic.c

@@ -14,13 +14,6 @@ plicinit(void)
   // set desired IRQ priorities non-zero (otherwise disabled).
   *(uint32*)(PLIC + UART0_IRQ*4) = 1;
   *(uint32*)(PLIC + VIRTIO0_IRQ*4) = 1;
-  
-#ifdef LAB_NET
-  // PCIE IRQs are 32 to 35
-  for(int irq = 1; irq < 0x35; irq++){
-    *(uint32*)(PLIC + irq*4) = 1;
-  }
-#endif  
 }
 
 void
@@ -32,11 +25,6 @@ plicinithart(void)
   // for the uart and virtio disk.
   *(uint32*)PLIC_SENABLE(hart) = (1 << UART0_IRQ) | (1 << VIRTIO0_IRQ);
 
-#ifdef LAB_NET
-  // hack to get at next 32 IRQs for e1000
-  *(uint32*)(PLIC_SENABLE(hart)+4) = 0xffffffff;
-#endif
-  
   // set this hart's S-mode priority threshold to 0.
   *(uint32*)PLIC_SPRIORITY(hart) = 0;
 }

kernel/spinlock.c

@@ -8,52 +8,12 @@
 #include "proc.h"
 #include "defs.h"
 
-#ifdef LAB_LOCK
-#define NLOCK 500
-
-static struct spinlock *locks[NLOCK];
-struct spinlock lock_locks;
-
-void
-freelock(struct spinlock *lk)
-{
-  acquire(&lock_locks);
-  int i;
-  for (i = 0; i < NLOCK; i++) {
-    if(locks[i] == lk) {
-      locks[i] = 0;
-      break;
-    }
-  }
-  release(&lock_locks);
-}
-
-static void
-findslot(struct spinlock *lk) {
-  acquire(&lock_locks);
-  int i;
-  for (i = 0; i < NLOCK; i++) {
-    if(locks[i] == 0) {
-      locks[i] = lk;
-      release(&lock_locks);
-      return;
-    }
-  }
-  panic("findslot");
-}
-#endif
-
 void
 initlock(struct spinlock *lk, char *name)
 {
   lk->name = name;
   lk->locked = 0;
   lk->cpu = 0;
-#ifdef LAB_LOCK
-  lk->nts = 0;
-  lk->n = 0;
-  findslot(lk);
-#endif  
 }
 
 // Acquire the lock.
@@ -65,21 +25,12 @@ acquire(struct spinlock *lk)
   if(holding(lk))
     panic("acquire");
 
-#ifdef LAB_LOCK
-    __sync_fetch_and_add(&(lk->n), 1);
-#endif      
-
   // On RISC-V, sync_lock_test_and_set turns into an atomic swap:
   //   a5 = 1
   //   s1 = &lk->locked
   //   amoswap.w.aq a5, a5, (s1)
-  while(__sync_lock_test_and_set(&lk->locked, 1) != 0) {
+  while(__sync_lock_test_and_set(&lk->locked, 1) != 0)
-#ifdef LAB_LOCK
+    ;
-    __sync_fetch_and_add(&(lk->nts), 1);
-#else
-   ;
-#endif
-  }
 
   // Tell the C compiler and the processor to not move loads or stores
   // past this point, to ensure that the critical section's memory
@@ -157,69 +108,3 @@ pop_off(void)
   if(c->noff == 0 && c->intena)
     intr_on();
 }
-
-// Read a shared 64-bit value without holding a lock
-uint64
-lockfree_read8(uint64 *addr) {
-  uint64 val;
-  __atomic_load(addr, &val, __ATOMIC_SEQ_CST);
-  return val;
-}
-
-// Read a shared 32-bit value without holding a lock
-int
-lockfree_read4(int *addr) {
-  uint32 val;
-  __atomic_load(addr, &val, __ATOMIC_SEQ_CST);
-  return val;
-}
-
-#ifdef LAB_LOCK
-int
-snprint_lock(char *buf, int sz, struct spinlock *lk)
-{
-  int n = 0;
-  if(lk->n > 0) {
-    n = snprintf(buf, sz, "lock: %s: #test-and-set %d #acquire() %d\n",
-                 lk->name, lk->nts, lk->n);
-  }
-  return n;
-}
-
-int
-statslock(char *buf, int sz) {
-  int n;
-  int tot = 0;
-
-  acquire(&lock_locks);
-  n = snprintf(buf, sz, "--- lock kmem/bcache stats\n");
-  for(int i = 0; i < NLOCK; i++) {
-    if(locks[i] == 0)
-      break;
-    if(strncmp(locks[i]->name, "bcache", strlen("bcache")) == 0 ||
-       strncmp(locks[i]->name, "kmem", strlen("kmem")) == 0) {
-      tot += locks[i]->nts;
-      n += snprint_lock(buf +n, sz-n, locks[i]);
-    }
-  }
-  
-  n += snprintf(buf+n, sz-n, "--- top 5 contended locks:\n");
-  int last = 100000000;
-  // stupid way to compute top 5 contended locks
-  for(int t = 0; t < 5; t++) {
-    int top = 0;
-    for(int i = 0; i < NLOCK; i++) {
-      if(locks[i] == 0)
-        break;
-      if(locks[i]->nts > locks[top]->nts && locks[i]->nts < last) {
-        top = i;
-      }
-    }
-    n += snprint_lock(buf+n, sz-n, locks[top]);
-    last = locks[top]->nts;
-  }
-  n += snprintf(buf+n, sz-n, "tot= %d\n", tot);
-  release(&lock_locks);  
-  return n;
-}
-#endif

kernel/syscall.c

@@ -102,13 +102,6 @@ extern uint64 sys_link(void);
 extern uint64 sys_mkdir(void);
 extern uint64 sys_close(void);
 
-#ifdef LAB_NET
-extern uint64 sys_connect(void);
-#endif
-#ifdef LAB_PGTBL
-extern uint64 sys_pgaccess(void);
-#endif
-
 // An array mapping syscall numbers from syscall.h
 // to the function that handles the system call.
 static uint64 (*syscalls[])(void) = {
@@ -133,16 +126,8 @@ static uint64 (*syscalls[])(void) = {
 [SYS_link]    sys_link,
 [SYS_mkdir]   sys_mkdir,
 [SYS_close]   sys_close,
-#ifdef LAB_NET
-[SYS_connect] sys_connect,
-#endif
-#ifdef LAB_PGTBL
-[SYS_pgaccess] sys_pgaccess,
-#endif
 };
 
-
-
 void
 syscall(void)
 {

kernel/syscall.h

@@ -20,14 +20,3 @@
 #define SYS_link   19
 #define SYS_mkdir  20
 #define SYS_close  21
-
-// System calls for labs
-#define SYS_trace     22
-#define SYS_sysinfo   23
-#define SYS_sigalarm  24
-#define SYS_sigreturn 25
-#define SYS_symlink   26
-#define SYS_mmap      27
-#define SYS_munmap    28
-#define SYS_connect   29
-#define SYS_pgaccess  30

kernel/sysfile.c

@@ -503,29 +503,3 @@ sys_pipe(void)
   }
   return 0;
 }
-
-
-#ifdef LAB_NET
-int
-sys_connect(void)
-{
-  struct file *f;
-  int fd;
-  uint32 raddr;
-  uint32 rport;
-  uint32 lport;
-
-  argint(0, (int*)&raddr);
-  argint(1, (int*)&lport);
-  argint(2, (int*)&rport);
-
-  if(sockalloc(&f, raddr, lport, rport) < 0)
-    return -1;
-  if((fd=fdalloc(f)) < 0){
-    fileclose(f);
-    return -1;
-  }
-
-  return fd;
-}
-#endif

kernel/sysnet.c

@@ -1,185 +0,0 @@
-//
-// network system calls.
-//
-
-#include "types.h"
-#include "param.h"
-#include "memlayout.h"
-#include "riscv.h"
-#include "spinlock.h"
-#include "proc.h"
-#include "defs.h"
-#include "fs.h"
-#include "sleeplock.h"
-#include "file.h"
-#include "net.h"
-
-struct sock {
-  struct sock *next; // the next socket in the list
-  uint32 raddr;      // the remote IPv4 address
-  uint16 lport;      // the local UDP port number
-  uint16 rport;      // the remote UDP port number
-  struct spinlock lock; // protects the rxq
-  struct mbufq rxq;  // a queue of packets waiting to be received
-};
-
-static struct spinlock lock;
-static struct sock *sockets;
-
-void
-sockinit(void)
-{
-  initlock(&lock, "socktbl");
-}
-
-int
-sockalloc(struct file **f, uint32 raddr, uint16 lport, uint16 rport)
-{
-  struct sock *si, *pos;
-
-  si = 0;
-  *f = 0;
-  if ((*f = filealloc()) == 0)
-    goto bad;
-  if ((si = (struct sock*)kalloc()) == 0)
-    goto bad;
-
-  // initialize objects
-  si->raddr = raddr;
-  si->lport = lport;
-  si->rport = rport;
-  initlock(&si->lock, "sock");
-  mbufq_init(&si->rxq);
-  (*f)->type = FD_SOCK;
-  (*f)->readable = 1;
-  (*f)->writable = 1;
-  (*f)->sock = si;
-
-  // add to list of sockets
-  acquire(&lock);
-  pos = sockets;
-  while (pos) {
-    if (pos->raddr == raddr &&
-        pos->lport == lport &&
-	pos->rport == rport) {
-      release(&lock);
-      goto bad;
-    }
-    pos = pos->next;
-  }
-  si->next = sockets;
-  sockets = si;
-  release(&lock);
-  return 0;
-
-bad:
-  if (si)
-    kfree((char*)si);
-  if (*f)
-    fileclose(*f);
-  return -1;
-}
-
-void
-sockclose(struct sock *si)
-{
-  struct sock **pos;
-  struct mbuf *m;
-
-  // remove from list of sockets
-  acquire(&lock);
-  pos = &sockets;
-  while (*pos) {
-    if (*pos == si){
-      *pos = si->next;
-      break;
-    }
-    pos = &(*pos)->next;
-  }
-  release(&lock);
-
-  // free any pending mbufs
-  while (!mbufq_empty(&si->rxq)) {
-    m = mbufq_pophead(&si->rxq);
-    mbuffree(m);
-  }
-
-  kfree((char*)si);
-}
-
-int
-sockread(struct sock *si, uint64 addr, int n)
-{
-  struct proc *pr = myproc();
-  struct mbuf *m;
-  int len;
-
-  acquire(&si->lock);
-  while (mbufq_empty(&si->rxq) && !pr->killed) {
-    sleep(&si->rxq, &si->lock);
-  }
-  if (pr->killed) {
-    release(&si->lock);
-    return -1;
-  }
-  m = mbufq_pophead(&si->rxq);
-  release(&si->lock);
-
-  len = m->len;
-  if (len > n)
-    len = n;
-  if (copyout(pr->pagetable, addr, m->head, len) == -1) {
-    mbuffree(m);
-    return -1;
-  }
-  mbuffree(m);
-  return len;
-}
-
-int
-sockwrite(struct sock *si, uint64 addr, int n)
-{
-  struct proc *pr = myproc();
-  struct mbuf *m;
-
-  m = mbufalloc(MBUF_DEFAULT_HEADROOM);
-  if (!m)
-    return -1;
-
-  if (copyin(pr->pagetable, mbufput(m, n), addr, n) == -1) {
-    mbuffree(m);
-    return -1;
-  }
-  net_tx_udp(m, si->raddr, si->lport, si->rport);
-  return n;
-}
-
-// called by protocol handler layer to deliver UDP packets
-void
-sockrecvudp(struct mbuf *m, uint32 raddr, uint16 lport, uint16 rport)
-{
-  //
-  // Find the socket that handles this mbuf and deliver it, waking
-  // any sleeping reader. Free the mbuf if there are no sockets
-  // registered to handle it.
-  //
-  struct sock *si;
-
-  acquire(&lock);
-  si = sockets;
-  while (si) {
-    if (si->raddr == raddr && si->lport == lport && si->rport == rport)
-      goto found;
-    si = si->next;
-  }
-  release(&lock);
-  mbuffree(m);
-  return;
-
-found:
-  acquire(&si->lock);
-  mbufq_pushtail(&si->rxq, m);
-  wakeup(&si->rxq);
-  release(&si->lock);
-  release(&lock);
-}

kernel/sysproc.c

@@ -55,8 +55,6 @@ sys_sleep(void)
   uint ticks0;
 
   argint(0, &n);
-  if(n < 0)
-    n = 0;
   acquire(&tickslock);
   ticks0 = ticks;
   while(ticks - ticks0 < n){

kernel/trap.c

@@ -68,8 +68,6 @@ usertrap(void)
   } else if((which_dev = devintr()) != 0){
     // ok
   } else {
-
-    
     printf("usertrap(): unexpected scause %p pid=%d\n", r_scause(), p->pid);
     printf("            sepc=%p stval=%p\n", r_sepc(), r_stval());
     setkilled(p);
@@ -77,7 +75,6 @@ usertrap(void)
 
   if(killed(p))
     exit(-1);
-  
 
   // give up the CPU if this is a timer interrupt.
   if(which_dev == 2)
@@ -193,13 +190,7 @@ devintr()
       uartintr();
     } else if(irq == VIRTIO0_IRQ){
       virtio_disk_intr();
-    }
+    } else if(irq){
-#ifdef LAB_NET
-    else if(irq == E1000_IRQ){
-      e1000_intr();
-    }
-#endif
-    else if(irq){
       printf("unexpected interrupt irq=%d\n", irq);
     }
 

kernel/vm.c

@@ -4,8 +4,6 @@
 #include "elf.h"
 #include "riscv.h"
 #include "defs.h"
-#include "spinlock.h"
-#include "proc.h"
 #include "fs.h"
 
 /*
@@ -32,14 +30,6 @@ kvmmake(void)
   // virtio mmio disk interface
   kvmmap(kpgtbl, VIRTIO0, VIRTIO0, PGSIZE, PTE_R | PTE_W);
 
-#ifdef LAB_NET
-  // PCI-E ECAM (configuration space), for pci.c
-  kvmmap(kpgtbl, 0x30000000L, 0x30000000L, 0x10000000, PTE_R | PTE_W);
-
-  // pci.c maps the e1000's registers here.
-  kvmmap(kpgtbl, 0x40000000L, 0x40000000L, 0x20000, PTE_R | PTE_W);
-#endif  
-
   // PLIC
   kvmmap(kpgtbl, PLIC, PLIC, 0x400000, PTE_R | PTE_W);
 
@@ -189,10 +179,8 @@ uvmunmap(pagetable_t pagetable, uint64 va, uint64 npages, int do_free)
   for(a = va; a < va + npages*PGSIZE; a += PGSIZE){
     if((pte = walk(pagetable, a, 0)) == 0)
       panic("uvmunmap: walk");
-    if((*pte & PTE_V) == 0) {
+    if((*pte & PTE_V) == 0)
-      printf("va=%p pte=%p\n", a, *pte);
       panic("uvmunmap: not mapped");
-    }
     if(PTE_FLAGS(*pte) == PTE_V)
       panic("uvmunmap: not a leaf");
     if(do_free){
@@ -389,7 +377,7 @@ int
 copyin(pagetable_t pagetable, char *dst, uint64 srcva, uint64 len)
 {
   uint64 n, va0, pa0;
-  
+
   while(len > 0){
     va0 = PGROUNDDOWN(srcva);
     pa0 = walkaddr(pagetable, va0);
@@ -449,6 +437,3 @@ copyinstr(pagetable_t pagetable, char *dst, uint64 srcva, uint64 max)
     return -1;
   }
 }
-
-
-

ping.py

@@ -1,12 +0,0 @@
-import socket
-import sys
-import time
-
-sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-addr = ('localhost', int(sys.argv[1]))
-buf = "this is a ping!".encode('utf-8')
-
-while True:
-	print("pinging...", file=sys.stderr)
-	sock.sendto(buf, ("127.0.0.1", int(sys.argv[1])))
-	time.sleep(1)

server.py

@@ -1,13 +0,0 @@
-import socket
-import sys
-
-sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-addr = ('localhost', int(sys.argv[1]))
-print('listening on %s port %s' % addr, file=sys.stderr)
-sock.bind(addr)
-
-while True:
-    buf, raddr = sock.recvfrom(4096)
-    print(buf.decode("utf-8"), file=sys.stderr)
-    if buf:
-        sent = sock.sendto(b'this is the host!', raddr)

time.txt

@@ -1 +1 @@
-5
+6

user/cat.c

@@ -1,6 +1,5 @@
 #include "kernel/types.h"
 #include "kernel/stat.h"
-#include "kernel/fcntl.h"
 #include "user/user.h"
 
 char buf[512];
@@ -33,7 +32,7 @@ main(int argc, char *argv[])
   }
 
   for(i = 1; i < argc; i++){
-    if((fd = open(argv[i], O_RDONLY)) < 0){
+    if((fd = open(argv[i], 0)) < 0){
       fprintf(2, "cat: cannot open %s\n", argv[i]);
       exit(1);
     }

user/find.c

@@ -0,0 +1,74 @@
+#include "kernel/types.h"
+#include "user/user.h"
+#include "kernel/stat.h"
+#include "kernel/fs.h"
+
+int fmtname(const char *path) {
+  int p;
+  for(p=strlen(path); p >= 0 && *(path + p) != '/'; p--);
+  p++;
+  return p;
+}
+
+void find(const char *path, const char* target) {
+    char buf[512], *p;
+    int fd;
+    struct dirent de;
+    struct stat st;
+    if((fd = open(path, 0)) < 0){
+        fprintf(2, "find: cannot open %s\n", path);
+        return;
+    }
+
+    if(fstat(fd, &st) < 0){
+        fprintf(2, "find: cannot stat %s\n", path);
+        close(fd);
+        return;
+    }
+
+    switch(st.type){
+    case T_DEVICE:
+    case T_FILE:
+        if (strcmp(path + fmtname(path), target) == 0) {
+            printf("%s\n", path);
+        }
+        break;
+
+    case T_DIR:
+        if (strcmp(path + fmtname(path), target) == 0) {
+            printf("%s\n", path);
+        }
+        if(strlen(path) + 1 + DIRSIZ + 1 > sizeof buf){
+            printf("find: path too long\n");
+            break;
+        }
+        strcpy(buf, path);
+        p = buf+strlen(buf);
+        *p++ = '/';
+        while(read(fd, &de, sizeof(de)) == sizeof(de)){
+            if(de.inum == 0)
+                continue;
+            if (strcmp(de.name, ".") == 0 || strcmp(de.name, "..") == 0)
+                continue;
+            memmove(p, de.name, DIRSIZ);
+            p[DIRSIZ] = 0;
+            if(stat(buf, &st) < 0){
+                printf("find: cannot stat %s\n", buf);
+                continue;
+            }
+            find(buf, target);
+        }
+        break;
+    }
+    close(fd);
+}
+
+int main(int argc, char** argv) {
+    if (argc != 3) {
+        printf("\x1b[31mInvalid arguments\x1b[0m\n");
+        printf("\x1b[32musage\x1b[0m: find <base directory> <file name to find>\n");
+        exit(0);
+    }
+    find(argv[1], argv[2]);
+    exit(0);
+}

user/grep.c

@@ -2,7 +2,6 @@
 
 #include "kernel/types.h"
 #include "kernel/stat.h"
-#include "kernel/fcntl.h"
 #include "user/user.h"
 
 char buf[1024];
@@ -52,7 +51,7 @@ main(int argc, char *argv[])
   }
 
   for(i = 2; i < argc; i++){
-    if((fd = open(argv[i], O_RDONLY)) < 0){
+    if((fd = open(argv[i], 0)) < 0){
       printf("grep: cannot open %s\n", argv[i]);
       exit(1);
     }

user/ls.c

@@ -2,7 +2,6 @@
 #include "kernel/stat.h"
 #include "user/user.h"
 #include "kernel/fs.h"
-#include "kernel/fcntl.h"
 
 char*
 fmtname(char *path)
@@ -31,7 +30,7 @@ ls(char *path)
   struct dirent de;
   struct stat st;
 
-  if((fd = open(path, O_RDONLY)) < 0){
+  if((fd = open(path, 0)) < 0){
     fprintf(2, "ls: cannot open %s\n", path);
     return;
   }

user/nettests.c

@@ -1,297 +0,0 @@
-#include "kernel/types.h"
-#include "kernel/net.h"
-#include "kernel/stat.h"
-#include "user/user.h"
-
-//
-// send a UDP packet to the localhost (outside of qemu),
-// and receive a response.
-//
-static void
-ping(uint16 sport, uint16 dport, int attempts)
-{
-  int fd;
-  char *obuf = "a message from xv6!";
-  uint32 dst;
-
-  // 10.0.2.2, which qemu remaps to the external host,
-  // i.e. the machine you're running qemu on.
-  dst = (10 << 24) | (0 << 16) | (2 << 8) | (2 << 0);
-
-  // you can send a UDP packet to any Internet address
-  // by using a different dst.
-  
-  if((fd = connect(dst, sport, dport)) < 0){
-    fprintf(2, "ping: connect() failed\n");
-    exit(1);
-  }
-
-  for(int i = 0; i < attempts; i++) {
-    if(write(fd, obuf, strlen(obuf)) < 0){
-      fprintf(2, "ping: send() failed\n");
-      exit(1);
-    }
-  }
-
-  char ibuf[128];
-  int cc = read(fd, ibuf, sizeof(ibuf)-1);
-  if(cc < 0){
-    fprintf(2, "ping: recv() failed\n");
-    exit(1);
-  }
-
-  close(fd);
-  ibuf[cc] = '\0';
-  if(strcmp(ibuf, "this is the host!") != 0){
-    fprintf(2, "ping didn't receive correct payload\n");
-    exit(1);
-  }
-}
-
-// Encode a DNS name
-static void
-encode_qname(char *qn, char *host)
-{
-  char *l = host; 
-  
-  for(char *c = host; c < host+strlen(host)+1; c++) {
-    if(*c == '.') {
-      *qn++ = (char) (c-l);
-      for(char *d = l; d < c; d++) {
-        *qn++ = *d;
-      }
-      l = c+1; // skip .
-    }
-  }
-  *qn = '\0';
-}
-
-// Decode a DNS name
-static void
-decode_qname(char *qn, int max)
-{
-  char *qnMax = qn + max;
-  while(1){
-    if(qn >= qnMax){
-      printf("invalid DNS reply\n");
-      exit(1);
-    }
-    int l = *qn;
-    if(l == 0)
-      break;
-    for(int i = 0; i < l; i++) {
-      *qn = *(qn+1);
-      qn++;
-    }
-    *qn++ = '.';
-  }
-}
-
-// Make a DNS request
-static int
-dns_req(uint8 *obuf)
-{
-  int len = 0;
-  
-  struct dns *hdr = (struct dns *) obuf;
-  hdr->id = htons(6828);
-  hdr->rd = 1;
-  hdr->qdcount = htons(1);
-  
-  len += sizeof(struct dns);
-  
-  // qname part of question
-  char *qname = (char *) (obuf + sizeof(struct dns));
-  char *s = "pdos.csail.mit.edu.";
-  encode_qname(qname, s);
-  len += strlen(qname) + 1;
-
-  // constants part of question
-  struct dns_question *h = (struct dns_question *) (qname+strlen(qname)+1);
-  h->qtype = htons(0x1);
-  h->qclass = htons(0x1);
-
-  len += sizeof(struct dns_question);
-  return len;
-}
-
-// Process DNS response
-static void
-dns_rep(uint8 *ibuf, int cc)
-{
-  struct dns *hdr = (struct dns *) ibuf;
-  int len;
-  char *qname = 0;
-  int record = 0;
-
-  if(cc < sizeof(struct dns)){
-    printf("DNS reply too short\n");
-    exit(1);
-  }
-
-  if(!hdr->qr) {
-    printf("Not a DNS reply for %d\n", ntohs(hdr->id));
-    exit(1);
-  }
-
-  if(hdr->id != htons(6828)){
-    printf("DNS wrong id: %d\n", ntohs(hdr->id));
-    exit(1);
-  }
-  
-  if(hdr->rcode != 0) {
-    printf("DNS rcode error: %x\n", hdr->rcode);
-    exit(1);
-  }
-  
-  //printf("qdcount: %x\n", ntohs(hdr->qdcount));
-  //printf("ancount: %x\n", ntohs(hdr->ancount));
-  //printf("nscount: %x\n", ntohs(hdr->nscount));
-  //printf("arcount: %x\n", ntohs(hdr->arcount));
-  
-  len = sizeof(struct dns);
-
-  for(int i =0; i < ntohs(hdr->qdcount); i++) {
-    char *qn = (char *) (ibuf+len);
-    qname = qn;
-    decode_qname(qn, cc - len);
-    len += strlen(qn)+1;
-    len += sizeof(struct dns_question);
-  }
-
-  for(int i = 0; i < ntohs(hdr->ancount); i++) {
-    if(len >= cc){
-      printf("invalid DNS reply\n");
-      exit(1);
-    }
-    
-    char *qn = (char *) (ibuf+len);
-
-    if((int) qn[0] > 63) {  // compression?
-      qn = (char *)(ibuf+qn[1]);
-      len += 2;
-    } else {
-      decode_qname(qn, cc - len);
-      len += strlen(qn)+1;
-    }
-      
-    struct dns_data *d = (struct dns_data *) (ibuf+len);
-    len += sizeof(struct dns_data);
-    //printf("type %d ttl %d len %d\n", ntohs(d->type), ntohl(d->ttl), ntohs(d->len));
-    if(ntohs(d->type) == ARECORD && ntohs(d->len) == 4) {
-      record = 1;
-      printf("DNS arecord for %s is ", qname ? qname : "" );
-      uint8 *ip = (ibuf+len);
-      printf("%d.%d.%d.%d\n", ip[0], ip[1], ip[2], ip[3]);
-      if(ip[0] != 128 || ip[1] != 52 || ip[2] != 129 || ip[3] != 126) {
-        printf("wrong ip address");
-        exit(1);
-      }
-      len += 4;
-    }
-  }
-
-  // needed for DNS servers with EDNS support
-  for(int i = 0; i < ntohs(hdr->arcount); i++) {
-    char *qn = (char *) (ibuf+len);
-    if(*qn != 0) {
-      printf("invalid name for EDNS\n");
-      exit(1);
-    }
-    len += 1;
-
-    struct dns_data *d = (struct dns_data *) (ibuf+len);
-    len += sizeof(struct dns_data);
-    if(ntohs(d->type) != 41) {
-      printf("invalid type for EDNS\n");
-      exit(1);
-    }
-    len += ntohs(d->len);
-  }
-
-  if(len != cc) {
-    printf("Processed %d data bytes but received %d\n", len, cc);
-    exit(1);
-  }
-  if(!record) {
-    printf("Didn't receive an arecord\n");
-    exit(1);
-  }
-}
-
-static void
-dns()
-{
-  #define N 1000
-  uint8 obuf[N];
-  uint8 ibuf[N];
-  uint32 dst;
-  int fd;
-  int len;
-
-  memset(obuf, 0, N);
-  memset(ibuf, 0, N);
-  
-  // 8.8.8.8: google's name server
-  dst = (8 << 24) | (8 << 16) | (8 << 8) | (8 << 0);
-
-  if((fd = connect(dst, 10000, 53)) < 0){
-    fprintf(2, "ping: connect() failed\n");
-    exit(1);
-  }
-
-  len = dns_req(obuf);
-  
-  if(write(fd, obuf, len) < 0){
-    fprintf(2, "dns: send() failed\n");
-    exit(1);
-  }
-  int cc = read(fd, ibuf, sizeof(ibuf));
-  if(cc < 0){
-    fprintf(2, "dns: recv() failed\n");
-    exit(1);
-  }
-  dns_rep(ibuf, cc);
-
-  close(fd);
-}  
-
-int
-main(int argc, char *argv[])
-{
-  int i, ret;
-  uint16 dport = NET_TESTS_PORT;
-
-  printf("nettests running on port %d\n", dport);
-  
-  printf("testing ping: ");
-  ping(2000, dport, 1);
-  printf("OK\n");
-  
-  printf("testing single-process pings: ");
-  for (i = 0; i < 100; i++)
-    ping(2000, dport, 1);
-  printf("OK\n");
-  
-  printf("testing multi-process pings: ");
-  for (i = 0; i < 10; i++){
-    int pid = fork();
-    if (pid == 0){
-      ping(2000 + i + 1, dport, 1);
-      exit(0);
-    }
-  }
-  for (i = 0; i < 10; i++){
-    wait(&ret);
-    if (ret != 0)
-      exit(1);
-  }
-  printf("OK\n");
-  
-  printf("testing DNS\n");
-  dns();
-  printf("DNS OK\n");
-  
-  printf("all tests passed.\n");
-  exit(0);
-}

user/pingpong.c

@@ -1,52 +1,27 @@
 #include "kernel/types.h"
-#include "kernel/stat.h"
 #include "user/user.h"
 
-#define N 5
+int main(int argc, char** argv) {
-char buf[N];
+    int p[2]; // hell, read from p[0] and write to p[1] no matter in pa/ch
-
+    if (pipe(p) == -1) exit(1);
-void
+    uint8 senddata[] = {0xAC};
-pong(int *parent_to_child, int *child_to_parent) {
+    uint8 recvdata[] = {0};
-  if (read(parent_to_child[0], buf, N) < 0) {
+    int pid = fork();
-    printf("read failed\n");
+    if (pid == 0) {
-  }
+        // child
-  printf("%d: received %s\n", getpid(), buf);
+        if (read(p[0], recvdata, 1) != 1) printf("error child read\n");
-  if (write(child_to_parent[1], "pong", 4) != 4) {
+        close(p[0]);
-    printf("write failed\n");
+        printf("%d: received ping\n", getpid());
-  }
+        if (write(p[1], senddata, 1) != 1) printf("error child write\n");
-}
+        close(p[1]);
-
+        exit(0);
-void
+    }
-ping(int *parent_to_child, int *child_to_parent) {
+    else {
-  
+        if (write(p[1], senddata, 1) != 1) printf("error parent write\n");
-  if (write(parent_to_child[1], "ping", 4) != 4) {
+        close(p[1]);
-    printf("write failed\n");
+        if (read(p[0], recvdata, 1) != 1) printf("error parent read\n");
-  }
+        printf("%d: received pong\n", getpid());
-  if (read(child_to_parent[0], buf, N) < 0) {
+        close(p[0]);
-    printf("read failed\n");
+        exit(0);
-  }
+    }
-  printf("%d: received %s\n", getpid(), buf);
+}
-}
-
-int
-main(int argc, char *argv[])
-{
-  int parent_to_child[2];
-  int child_to_parent[2];
-
-  int pid;
-
-  if (pipe(parent_to_child) < 0 || pipe(child_to_parent) < 0) {
-    printf("pipe failed\n");
-  }
-  if ((pid = fork()) < 0) {
-    printf("fork failed\n");
-  }
-  if (pid == 0) {
-    pong(parent_to_child, child_to_parent);
-  } else {
-    ping(parent_to_child, child_to_parent);
-  }
-  
-  exit(0);
-}

user/primes.c

@@ -0,0 +1,51 @@
+#include "kernel/types.h"
+#include "user/user.h"
+
+void pipeline(int leftfd) {
+    int pipefd[2];
+    int p; read(leftfd, &p, sizeof(p));
+    printf("prime %d\n", p);
+    int n; 
+    int has_right = 0;
+    while (read(leftfd, &n, sizeof(n)) > 0) {
+        if (n % p != 0) {
+            if (!has_right) {
+                has_right = 1;
+                pipe(pipefd);
+                if (fork() == 0) {
+                    close(pipefd[1]);
+                    pipeline(pipefd[0]);
+                } else {
+                    close(pipefd[0]);
+                }
+            }
+            write(pipefd[1], &n, sizeof(n));
+        }
+    }
+    close(leftfd);
+    if (has_right) {
+        close(pipefd[1]);
+        while(wait(0) != -1);
+    }
+    exit(0);
+}
+
+int main(int argc, char** argv) {
+    int pipefd[2];
+    pipe(pipefd);
+    int pid = fork();
+    if (pid != 0) {
+        close(pipefd[0]); // no need to read in the feeding proc
+        for (int i = 2; i <= 35; ++ i) {
+            write(pipefd[1], &i, sizeof(i));
+        }
+        close(pipefd[1]);
+        while(wait(0) != -1);
+        exit(0);
+    }
+    else {
+        close(pipefd[1]);  // pipeline proc will have its own write pipe
+        pipeline(pipefd[0]);
+    }
+    exit(0);
+}

user/sleep.c

@@ -0,0 +1,17 @@
+#include "kernel/types.h"
+#include "user/user.h"
+
+int main(int argc, char** argv) {
+    if (argc != 2) {
+        printf("\x1b[31mUnexpected argument\x1b[0m\n");
+        printf("usage: sleep <ticks>\n");
+        exit(0);
+    }
+    int ticks = atoi(argv[1]);
+    int ret = sleep(ticks);
+    if (ret) {
+        printf("\x1b[31mFailed to sleep\x1b[0m\n");
+        exit(-1);
+    }
+    exit(0);
+}

user/user.h

@@ -22,14 +22,6 @@ int getpid(void);
 char* sbrk(int);
 int sleep(int);
 int uptime(void);
-#ifdef LAB_NET
-int connect(uint32, uint16, uint16);
-#endif
-#ifdef LAB_PGTBL
-int pgaccess(void *base, int len, void *mask);
-// usyscall region
-int ugetpid(void);
-#endif
 
 // ulib.c
 int stat(const char*, struct stat*);
@@ -47,4 +39,3 @@ void free(void*);
 int atoi(const char*);
 int memcmp(const void *, const void *, uint);
 void *memcpy(void *, const void *, uint);
-int statistics(void*, int);

user/usys.pl

@@ -36,5 +36,3 @@ entry("getpid");
 entry("sbrk");
 entry("sleep");
 entry("uptime");
-entry("connect");
-entry("pgaccess");

user/wc.c

@@ -1,6 +1,5 @@
 #include "kernel/types.h"
 #include "kernel/stat.h"
-#include "kernel/fcntl.h"
 #include "user/user.h"
 
 char buf[512];
@@ -44,7 +43,7 @@ main(int argc, char *argv[])
   }
 
   for(i = 1; i < argc; i++){
-    if((fd = open(argv[i], O_RDONLY)) < 0){
+    if((fd = open(argv[i], 0)) < 0){
       printf("wc: cannot open %s\n", argv[i]);
       exit(1);
     }

user/xargs.c

@@ -0,0 +1,59 @@
+#include "kernel/param.h"
+#include "kernel/types.h"
+#include "user/user.h"
+
+static inline int is_ws(const char ch) {
+    return ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r';
+}
+
+int main(int argc, char** argv) {
+    int STDIN = 0;
+    char linebuf[1024];
+    char* p = linebuf;
+    char* _argv[MAXARG];
+    while (read(STDIN, p, 1) > 0) {
+        if (*p == '\n') {
+            int i;
+            int in_ws = 1;
+            for (i = 0; i < argc - 1; ++i) {
+                _argv[i] = argv[i + 1];
+            }
+            for (char* p0 = linebuf; p0 <= p; ++p0) {
+                if (is_ws(*p0)) {
+                    if (!in_ws) {
+                        in_ws = 1;
+                        i++;
+                    }
+                    *p0 = '\0';
+                } else if (in_ws) {
+                    in_ws = 0;
+                    _argv[i] = p0;
+                }
+                if (i >= MAXARG) {
+                    printf("warning: too many arguments");
+                    break;
+                }
+            }
+            *p = '\0';
+            _argv[i] = 0;
+            // for (int j = 0; j < i; ++ j) {
+            //     printf("%s\n", _argv[j]);
+            // }
+            if (fork() == 0) {
+                exec(_argv[0], _argv);
+                exit(0);
+            } else {
+                p = linebuf;
+                while (wait(0) != -1)
+                    ;
+            }
+        } else {
+            p++;
+            if (p >= linebuf + sizeof(linebuf)) {
+                printf("line buffer exceeded\n");
+                exit(0);
+            }
+        }
+    }
+    exit(0);
+}

user/xargstest.sh

@@ -0,0 +1,6 @@
+mkdir a
+echo hello > a/b
+mkdir c
+echo hello > c/b
+echo hello > b
+find . b | xargs grep hello