print all cluster numbers ok

loader.asm

@@ -28,15 +28,15 @@ DispStr:
     pop    bp
     ret
 ;----------------------------------------------------------------------------
-; @param ax: the int to print
+; @param bp + 4: the word to print as uint_16t
 ;----------------------------------------------------------------------------
 ; print a word as decimal to current cursor
-
 DispInt:
     push    bp
     mov     bp, sp
     pusha
     mov di, 0
+    mov ax, [bp + 4]
 .loop1:
     mov dx, 0
     mov bx, 10
@@ -61,8 +61,9 @@ DispInt:
     pop    bp
     ret
 ;----------------------------------------------------------------------------
-; give you a new line
+; no param
 ;----------------------------------------------------------------------------
+; give you a new line
 DispNewline:
     push    bp
     mov     bp, sp
@@ -81,6 +82,27 @@ DispNewline:
     ret
 
 ;----------------------------------------------------------------------------
+; @param bp + 4: low byte holds the ascii to print
+;----------------------------------------------------------------------------
+; putchar to current cursor pos
+DispPutchar:
+    push    bp
+    mov     bp, sp
+    pusha
+    ; get cursor pos
+    mov ax, 0300h
+    mov bh, 0
+    int 10h
+    ; putchar
+    mov ax, [bp + 4]
+    mov ah, 0Eh ; no need to set al, ax holds the param
+    mov bl, 0Fh
+    int 10H
+
+    popa
+    pop    bp
+    ret
+;----------------------------------------------------------------------------
 ; 函数名: StringCmp
 ;----------------------------------------------------------------------------
 ; 作用:
@@ -143,11 +165,11 @@ ReadSector:
     pop    bp
     ret
 .ReadFail:
-
     jmp    $                     ; 如果cf位置1，就意味着读入错误，这个时候建议直接开摆
 
 ;------------------------------------------------------------------------------
 ; 函数名: GetNextCluster
+; data => BaseOfSectorBuf : 0
 ;------------------------------------------------------------------------------
 ; 作用:
 ;    ax存放的是当前的簇(cluster)号，根据当前的簇号在fat表里查找，找到下一个簇的簇号，并将返回值存放在ax
@@ -176,9 +198,9 @@ GetNextCluster:
     mov    ax, [es:bx]
     pop    bx                 ; 取回奇数标识信息
     cmp    bx, 0              ; 如果是第奇数个FAT项还得右移四位
-    jz     EvenCluster        ; 可能是微软(FAT是微软创建的)第一个亲儿子的原因，有它的历史局限性
+    jz     .EvenCluster       ; 可能是微软(FAT是微软创建的)第一个亲儿子的原因，有它的历史局限性
     shr    ax, 4              ; 当时的磁盘很脆弱，经常容易写坏，所以需要两张FAT表备份，而且人们能够制作的存储设备的容量很小
-EvenCluster:
+.EvenCluster:
     and    ax, 0FFFh          ; 读完需要与一下，因为高位是未定义的，防止ax值有误
     mov    word [bp - 2], ax  ; 这里用了一个技巧，这样在popa的时候ax也顺便更新了
 
@@ -191,7 +213,7 @@ EvenCluster:
 ; @retval ax: first cluster no
 ;------------------------------------------------------------------------------
 ; Find File by name, return first cluster no.
-
+; data => BaseOfSectorBuf:OffsetOfSectorBuf
 FuncFindFile:
     push   bp
     mov    bp, sp
@@ -247,58 +269,86 @@ FuncFindFile:
     pop    bp
     ret
 
+;------------------------------------------------------------------------------
+; @param bp + 4: first cluster number
+;------------------------------------------------------------------------------
+; Find File by name, return first cluster no.
+; data => BaseOfSectorBuf:OffsetOfSectorBuf
+FuncPrintClusterNumbers:
+    push    bp
+    mov     bp, sp
+    pusha
+    mov     ax, [bp + 4]
+.loop:
+    mov     ax, dx
+    push    ax
+    call    DispInt             ; ax now holds the current cluster number
+    add     sp, 2
+    push    ' '
+    call    DispPutchar
+    add     sp, 2
+
+    call    GetNextCluster      ; 根据数据区簇号获取文件下一个簇的簇号
+    mov     dx, ax              ; dx <- 下一个簇的簇号
+    cmp     dx, 0FFFh           ; 判断是否读完了（根据文档理论上dx只要在0xFF8~0xFFF都行，但是这里直接偷懒只判断0xFFF）
+    jnz     .loop
+
+    popa
+    pop     bp
+    ret
+
 MAIN:
     mov    ax, cs                ; cs <- 0
     mov    ds, ax                ; ds <- 0
     mov    ss, ax                ; ss <- 0
     mov    ax, BaseOfSectorBuf
     mov    es, ax                ; es <- BaseOfSectorBuf
-
+; Display "This is {name}'s boot"
     call    DispNewline
-    mov     ax, cs
-    push    ax
-    mov     ax, StudentString
-    push    ax
-    mov     ax, _endStudentString - StudentString
-    push    ax
-    call    DispStr
-    add     sp, 6               ; pop for 3 times
 
-    mov     ax, LoaderFileName
+    push    cs
-    push    ax
+    push    StudentString
+    push    _endStudentString - StudentString
+    call    DispStr
+    add     sp, 6                ; pop for 3 times
+
+; Read loader.bin's cluster number
+    push    LoaderFileName
     call    FuncFindFile
-    mov     dx, ax              ; temporarily save read result to dx
+    add     sp, 2
-    pop     ax
 
+    mov     dx, ax              ; temporarily save read result to dx
+; Print first cluster number
     call    DispNewline
-    mov     ax, cs
+
-    push    ax
+    push    cs
-    mov     ax, clusternoString
+    push    clusternoString
-    push    ax
+    push    _endclusternoString - clusternoString
-    mov     ax, _endclusternoString - clusternoString
-    push    ax
     call    DispStr
     add     sp, 6               ; pop for 3 times
-    mov     ax, dx              ; dx holds the read result
-    call    DispInt
 
-    mov     ax, AA1FileName
+    push    dx              ; dx holds the read result
-    push    ax
+    call    FuncPrintClusterNumbers
+    add     sp, 2
+
+; Read aA1.txt's cluster number
+    push    AA1FileName
     call    FuncFindFile
-    mov     dx, ax              ; temporarily save read result to dx
+    add     sp, 2
-    pop     ax
 
+    mov     dx, ax              ; temporarily save read result to dx
+; Print first cluster number
     call    DispNewline
-    mov     ax, cs
+
-    push    ax
+    push    cs
-    mov     ax, clusternoString
+    push    clusternoString
-    push    ax
+    push    _endclusternoString - clusternoString
-    mov     ax, _endclusternoString - clusternoString
-    push    ax
     call    DispStr
-    add     sp, 6               ; pop for 3 times
+    add     sp, 6
-    mov     ax, dx              ; dx holds the read result
+
-    call    DispInt
+    push    dx              ; dx holds the read result
+    call    FuncPrintClusterNumbers
+    add     sp, 2
     jmp $
 
 ;==============================================================================
@@ -307,7 +357,7 @@ MAIN:
 BaseOfStack             equ 07c00h      ; Boot状态下堆栈基地址(栈底, 从这个位置向低地址生长)
 ; according to osdev, memory from 0x0000:0x7e00 to 0x7000:0xFFFF is free to use
 BaseOfSectorBuf         equ 07000h      ; diff from where we are here
-OffsetOfSectorBuf       equ 0000h       ; diff from where we are here
+OffsetOfSectorBuf       equ 0400h       ; the first 400h(=1024d) bytes left for fat1 read buf
 RootDirSectors          equ 14          ; 19~32 
 SectorNoOfRootDirectory equ 19          ; Root Sector starts from 19
 SectorNoOfFAT1          equ 1
@@ -335,7 +385,7 @@ LeftRootDirSectors      dw    RootDirSectors          ; 还未搜索的根目录
 RootDirSectorNow        dw    SectorNoOfRootDirectory ; 目前正在搜索的根目录扇区
 BufferPacket            times 010h db 0               ; ReadSector函数会用到的，用于向int 13h中断的一个缓冲区
 
-LoaderFileName          db      "LOADE   BIN", 0  ; 8:3, fill with whitespace
+LoaderFileName          db      "LOADER  BIN", 0  ; 8:3, fill with whitespace
 AA1FileName             db      "AA1     TXT", 0  ; the 0 at end is for StrCmp
 StudentString           db      "This is LiMaoliang's boot" ; size = 25
 _endStudentString