544 lines
17 KiB
NASM
544 lines
17 KiB
NASM
;==============================================================================================================================
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BaseOfStack equ 0x07c00 ; Boot状态下堆栈基地址
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STACK_ADDR equ 0x7bea ; 堆栈栈顶
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BaseOfBoot equ 1000h ; added by mingxuan 2020-9-12
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OffsetOfBoot equ 7c00h ; load Boot sector to BaseOfBoot:OffsetOfBoot
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OffsetOfActiPartStartSec equ 7e00h ; 活动分区的起始扇区号相对于BaseOfBoot的偏移量 ;added by mingxuan 2020-9-12
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; 该变量来自分区表，保存在该内存地址，用于在os_boot和loader中查找FAT32文件
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BOOT_FAT32_INFO equ 0x5A ;位于boot中的FAT32配置信息的长度
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;added by mingxuan 2020-9-16
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DATA_BUF_OFF equ 0x2000 ; 目录 被加载的缓冲区地址
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OSLOADER_SEG equ 0x09000 ; 起始段地址
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OSLOADER_SEG_OFF equ 0x0100
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;FAT_START_SECTOR equ 0x820 ; FAT表的起始扇区号 DWORD
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;FAT_START_SECTOR equ 0x1020 ; FAT表的起始扇区号 DWORD ; for test 2020-9-10, mingxuan
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;DATA_START_SECTOR equ 0xd6a ; 数据区起始扇区号 DWORD
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;DATA_START_SECTOR equ 0x156a ; 数据区起始扇区号 DWORD ; for test 2020-9-10, mingxuan
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;DATA_START_SECTOR equ 0x13a4 ; 数据区起始扇区号 DWORD ; for test 2020-9-13, mingxuan
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DIR_PER_SECTOR equ 0x10 ; 每个扇区所容纳的目录 BYTE
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; 扩展磁盘服务所使用的地址包
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DAP_SECTOR_HIGH equ 4 ; 起始扇区号的高32位 ( 每次调用需要重置 ) DWORD
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DAP_SECTOR_LOW equ 8 ; 起始扇区号的低32位 ( 每次调用需要重置 ) DWORD
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DAP_BUFFER_SEG equ 10 ; 缓冲区段地址 ( 每次调用需要重置 ) WORD
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DAP_BUFFER_OFF equ 12 ; 缓冲区偏移 ( 每次调用需要重置 ) WORD
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DAP_RESERVED2 equ 13 ; 保留字节
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DAP_READ_SECTORS equ 14 ; 要处理的扇区数(1 - 127 )
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DAP_RESERVED1 equ 15 ; 保留字节
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DAP_PACKET_SIZE equ 16 ; 包的大小为16字节
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CURRENT_CLUSTER equ 20 ; 当前正在处理的簇号 DWORD
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; 目录项结构
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OFF_START_CLUSTER_HIGH equ 20 ; 起始簇号高位 WORD
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OFF_START_CLUSTER_LOW equ 26 ; 起始簇号低位 WORD
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; 相关常量
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DIR_NAME_FREE equ 0x00 ; 该项是空闲的
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DIR_ENTRY_SIZE equ 32 ; 每个目录项的尺寸
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; 簇属性
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CLUSTER_MASK equ 0FFFFFFFH ; 簇号掩码
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CLUSTER_LAST equ 0FFFFFF8H ;0xFFFFFFF8-0xFFFFFFFF表示文件的最后一个簇
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; added by mingxuan 2020-9-12
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BPB_BytesPerSec equ (OffsetOfBoot + 0xb) ;每扇区字节数
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BPB_SecPerClu equ (OffsetOfBoot + 0xd) ;每簇扇区数
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BPB_RsvdSecCnt equ (OffsetOfBoot + 0xe) ;保留扇区数
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BPB_NumFATs equ (OffsetOfBoot + 0x10) ;FAT表数
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BPB_RootEntCnt equ (OffsetOfBoot + 0x11) ;FAT32不使用
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BPB_TotSec16 equ (OffsetOfBoot + 0x13) ;扇区总数
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BPB_Media equ (OffsetOfBoot + 0x15) ;介质描述符
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BPB_FATSz16 equ (OffsetOfBoot + 0x16) ;每个FAT表的大小扇区数(FAT32不使用)
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BPB_SecPerTrk equ (OffsetOfBoot + 0x18) ;每磁道扇区数
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BPB_NumHeads equ (OffsetOfBoot + 0x1a) ;磁头数
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BPB_HiddSec equ (OffsetOfBoot + 0x1c) ;分区已使用扇区数
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BPB_TotSec32 equ (OffsetOfBoot + 0x20) ;文件系统大小扇区数
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BS_SecPerFAT equ (OffsetOfBoot + 0x24) ;每个FAT表大小扇区数
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BS_Flag equ (OffsetOfBoot + 0x28) ;标记
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BS_Version equ (OffsetOfBoot + 0x2a) ;版本号
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BS_RootClus equ (OffsetOfBoot + 0x2c) ;根目录簇号
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BS_FsInfoSec equ (OffsetOfBoot + 0x30) ;FSINFO扇区号
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BS_BackBootSec equ (OffsetOfBoot + 0x32) ;备份引导扇区位置
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BS_Unuse1 equ (OffsetOfBoot + 0x34) ;未使用
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;BS_Unuse2 equ (OffsetOfBoot + 0x40) ;未使用 ;deleted by mingxuan 2020-9-15
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;BS_Unuse3 equ (OffsetOfBoot + 0x41) ;未使用 ;deleted by mingxuan 2020-9-15
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BS_DriveNum equ (OffsetOfBoot + 0x40) ;设备号
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BS_Unuse4 equ (OffsetOfBoot + 0x41) ;未使用
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BS_ExtBootFlag equ (OffsetOfBoot + 0x42) ;扩展引导标志
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BS_VolNum equ (OffsetOfBoot + 0x43) ;卷序列号
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BS_VolName equ (OffsetOfBoot + 0x47) ;卷标
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;==============================================================================================================================
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;org 07c00h ;deleted by mingxuan 2020-9-16
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org (07c00h + BOOT_FAT32_INFO) ;FAT322规范规定第90~512个字节(共423个字节)是引导程序
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;modified by mingxuan 2020-9-16
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;jmp START ;deleted by mingxuan 2020-9-15
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;nop ;deleted by mingxuan 2020-9-15
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FAT_START_SECTOR DD 0 ;FAT表的起始扇区号 ;added by mingxuan 2020-9-17
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DATA_START_SECTOR DD 0 ;数据区起始扇区号 ;added by mingxuan 2020-9-17
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;deleted by mingxuan 2020-9-12
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;BS_OEM DB 'mkfs.fat' ;文件系统标志
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;BPB_BytesPerSec DW 0x200 ;每扇区字节数
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;BPB_SecPerClu DB 1 ;每簇扇区数
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;BPB_RsvdSecCnt DW 0x20 ;保留扇区数
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;BPB_NumFATs DB 2 ;FAT表数
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;BPB_RootEntCnt DW 0 ;FAT32不使用
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;BPB_TotSec16 DW 0 ;扇区总数
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;BPB_Media DB 0xf8 ;介质描述符
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;BPB_FATSz16 DW 0 ;每个FAT表的大小扇区数
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;BPB_SecPerTrk DW 0x3f ;每磁道扇区数
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;BPB_NumHeads DW 0xff ;磁头数
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;BPB_HiddSec DD 0 ;分区已使用扇区数
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;BPB_TotSec32 DD 0x015791 ;文件系统大小扇区数
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;BS_SecPerFAT DD 0x02a5 ;每个FAT表大小扇区数
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;BS_Flag DW 0 ;标记
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;BS_Version DW 0 ;版本号
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;BS_RootClus DD 2 ;根目录簇号
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;BS_FsInfoSec DW 1 ;FSINFO扇区号
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;BS_BackBootSec DW 6 ;备份引导扇区位置
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;BS_Unuse1 DD 0 ;未使用
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;BS_Unuse2 DD 0 ;未使用
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;BS_Unuse3 DD 0 ;未使用
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;BS_DriveNum DB 0x80 ;设备号
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;BS_Unuse4 DB 0x01 ;未使用
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;BS_ExtBootFlag DB 0x29 ;扩展引导标志
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;BS_VolNum DD 0xbe3a8ff5 ;卷序列号
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;BS_VolName DB 'MZY hd boot' ;卷标
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START:
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cld
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mov ax, cs
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mov ds, ax
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mov es, ax ;deleted by mingxuan 2020-9-13
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mov ss, ax
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; 清屏
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; for test, added by mingxuan 2020-9-15
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; pusha
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; mov dx, 0184fh ; 右下角: (80, 50)
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; int 10h ; int 10h
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; popa
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;added by mingxuan 2020-9-13
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;mov ax, BaseOfBoot
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;mov fs, ax ;es存储BaseOfBoot，用于查找FAT32的配置信息
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;FAT_START_SECTOR DD ([fs:OffsetOfActiPartStartSec] + [fs:BPB_RsvdSecCnt])
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; 计算FAT表的起始扇区号 ; added by mingxuan 2020-9-17
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mov eax, [ OffsetOfActiPartStartSec]
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add ax, [ BPB_RsvdSecCnt ]
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mov [FAT_START_SECTOR], eax
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; 计算数据区起始扇区号 ; added by mingxuan 2020-9-17
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add eax, [BS_SecPerFAT]
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add eax, [BS_SecPerFAT]
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mov [DATA_START_SECTOR], eax
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mov sp, STACK_ADDR
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mov bp, BaseOfStack
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mov dword [bp - DAP_SECTOR_HIGH ], 00h
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;mov byte [bp - DAP_RESERVED1 ], 00h ;deleted by mingxuan 2020-9-17
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;mov byte [bp - DAP_RESERVED2 ], 00h ;deleted by mingxuan 2020-9-17
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mov byte [bp - DAP_PACKET_SIZE ], 10h
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mov byte [bp - DAP_READ_SECTORS], 01h
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mov word [bp - DAP_BUFFER_SEG ], 01000h
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;for test, added by mingxuan 2020-9-4
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;call DispStr ;
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;jmp $
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jmp _SEARCH_LOADER
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_MISSING_LOADER: ; 显示没有装载程序
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;for test, added by mingxuan 2020-9-10
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;call DispStr ;
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;JMP $ ;for test, added by mingxuan 2020-9-10
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; 清屏
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; for test, added by mingxuan 2020-9-15
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;pusha
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;mov dx, 0184fh ; 右下角: (80, 50)
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;int 10h ; int 10h
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;popa
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_DISK_ERROR: ; 显示磁盘错误信息
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;for test, added by mingxuan 2020-9-4
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; 清屏
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; for test, added by mingxuan 2020-9-15
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;pusha
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;mov dx, 0184fh ; 右下角: (80, 50)
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;int 10h ; int 10h
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;popa
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JMP $
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ReadSector:
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pusha
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mov ah, 42h ;ah是功能号，扩展读对应0x42
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lea si, [BP - DAP_PACKET_SIZE] ;使用扩展int13时DAP结构体首地址传给si
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;mov dl, [BS_DriveNum] ;deleted by mingxuan 2020-9-13
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;mov es, BaseOfBoot ;modified by mingxuan 2020-9-13
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;mov dl, [fs:BS_DriveNum] ;modified by mingxuan 2020-9-13
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mov dl, [BS_DriveNum] ;modified by mingxuan 2020-9-17
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;mov dl, 0x80
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;jmp $
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int 13h
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jc _DISK_ERROR
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;jmp $
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; 清屏
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; for test, added by mingxuan 2020-9-15
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;pusha
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;mov dx, 0184fh ; 右下角: (80, 50)
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;int 10h ; int 10h
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;popa
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popa
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ret
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_SEARCH_LOADER:
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mov word [bp - DAP_BUFFER_OFF], DATA_BUF_OFF
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;mov eax, dword [BS_RootClus] ;deleted by mingxuan 2020-9-13
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;mov es, BaseOfBoot ;modified by mingxuan 2020-9-13
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;mov eax, dword [fs:BS_RootClus] ;modified by mingxuan 2020-9-13
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;mov eax, dword [BS_RootClus] ;modified by mingxuan 2020-9-17
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mov eax, [BS_RootClus]
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mov dword [bp - CURRENT_CLUSTER], eax
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;for test, added by mingxuan 2020-9-4
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;call DispStr ;
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;jmp $
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_NEXT_ROOT_CLUSTER:
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; 根据簇号计算扇区号, mingxuan 2020-9-13
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dec eax
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dec eax
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xor ebx, ebx
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;mov bl, byte [BPB_SecPerClu] ;deleted by mingxuan 2020-9-13
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;mov es, BaseOfBoot ;modified by mingxuan 2020-9-13
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;mov bl, byte [fs:BPB_SecPerClu] ;modified by mingxuan 2020-9-13
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mov bl, [BPB_SecPerClu] ;modified by mingxuan 2020-9-17
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;jmp $
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mul ebx
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;add eax, DATA_START_SECTOR ;deleted by mingxuan 2020-9-17
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add eax, [DATA_START_SECTOR] ;modified by mingxuan 2020-9-17
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mov dword [BP - DAP_SECTOR_LOW], eax
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;mov dl, [BPB_SecPerClu] ;deleted by mingxuan 2020-9-13
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;mov dl, byte [es:BPB_SecPerClu] ;modified by mingxuan 2020-9-13
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;mov dl, [fs:BPB_SecPerClu] ;modified by mingxuan 2020-9-15
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mov dl, [BPB_SecPerClu] ;modified by mingxuan 2020-9-17
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;jmp $
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_NEXT_ROOT_SECTOR:
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call ReadSector
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;for test, added by mingxuan 2020-9-4
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;call DispStr ;
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;jmp $
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mov di, DATA_BUF_OFF
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mov bl, DIR_PER_SECTOR
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_NEXT_ROOT_ENTRY:
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cmp byte [di], DIR_NAME_FREE
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jz _MISSING_LOADER
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push di;
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mov si, LoaderName
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;add si, BOOT_FAT32_INFO ; added by mingxuan 2020-9-16
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;mov si, 0x7df1 ; for test, added by mingxuan 2020-9-16
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mov cx, 10
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repe cmpsb
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jcxz _FOUND_LOADER
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pop di
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add di, DIR_ENTRY_SIZE
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dec bl
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jnz _NEXT_ROOT_ENTRY
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dec dl
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jz _CHECK_NEXT_ROOT_CLUSTER
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inc dword [bp - DAP_SECTOR_LOW]
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jmp _NEXT_ROOT_SECTOR
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; Comments, added by mingxuan 2020-9-10
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;====================================================================
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; 检查是否还有下一个簇(读取FAT表的相关信息)
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; N = 数据簇号
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; FAT_BYTES(在FAT表中的偏移) = N*4 (FAT32)
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; FAT_SECTOR = FAT_BYTES / BPB_BytesPerSec
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; FAT_OFFSET = FAT_BYTES % BPB_BytesPerSec
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;====================================================================
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_CHECK_NEXT_ROOT_CLUSTER: ; 检查是否还有下一个簇
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; 计算FAT表项所在的簇号和偏移
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; FatOffset(在FAT表中的偏移) = ClusterNum(簇号) * 4
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XOR EDX, EDX
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MOV EAX, DWORD[BP - CURRENT_CLUSTER]
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SHL EAX, 2 ;FatOffset = ClusterNum * 4
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XOR ECX, ECX
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;MOV CX, WORD [ BPB_BytesPerSec ] ;deleted by mingxuan 2020-9-13
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;mov es, BaseOfBoot ;modified by mingxuan 2020-9-13
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;mov cx, word [fs:BPB_BytesPerSec] ;modified by mingxuan 2020-9-13
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mov cx, word [BPB_BytesPerSec] ;modified by mingxuan 2020-9-17
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DIV ECX ; EAX = Sector EDX = OFFSET
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; 计算FAT表的起始扇区号
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; added by mingxuan 2020-9-17
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;mov ebx, dword [ fs:OffsetOfActiPartStartSec ]
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;add bx, word [ fs:BPB_RsvdSecCnt ]
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; 设置缓冲区地址
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;ADD EAX, FAT_START_SECTOR ;deleted by mingxuan 2020-9-17
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ADD EAX, [FAT_START_SECTOR] ;modified by mingxuan 2020-9-17
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;add eax, ebx ;modified by mingxuan 2020-9-17
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MOV DWORD [ BP - DAP_SECTOR_LOW ], EAX
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call ReadSector
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; 检查下一个簇
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MOV DI,DX
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ADD DI,DATA_BUF_OFF
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MOV EAX, DWORD[DI] ; EAX = 下一个要读的簇号
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AND EAX, CLUSTER_MASK
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MOV DWORD[ BP - CURRENT_CLUSTER ],EAX
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CMP EAX,CLUSTER_LAST ; CX >= 0FFFFFF8H，则意味着没有更多的簇了
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JB _NEXT_ROOT_CLUSTER
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;for test, added by mingxuan 2020-9-10
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;call DispStr ;
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JMP _MISSING_LOADER
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_FOUND_LOADER:
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;for test, added by mingxuan 2020-9-10
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;call DispStr ;
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;JMP $ ;for test, added by mingxuan 2020-9-10
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; 目录结构地址放在DI中
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pop di
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xor eax, eax
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mov ax, [di + OFF_START_CLUSTER_HIGH] ; 起始簇号高32位
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shl ax, 16
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mov ax, [di + OFF_START_CLUSTER_LOW] ; 起始簇号低32位
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mov dword [ bp - CURRENT_CLUSTER ], eax
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mov cx, OSLOADER_SEG ; CX = 缓冲区段地址
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; 清屏
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; for test, added by mingxuan 2020-9-15
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;pusha
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;mov dx, 0184fh ; 右下角: (80, 50)
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;int 10h ; int 10h
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;popa
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_NEXT_DATA_CLUSTER:
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; 根据簇号计算扇区号
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DEC EAX
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DEC EAX
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XOR EBX,EBX
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;MOV BL, BYTE [ BPB_SecPerClu ] ;deleted by mingxuan 2020-9-13
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;mov es, BaseOfBoot ;modified by mingxuan 2020-9-13
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;mov bl, byte [fs:BPB_SecPerClu] ;modified by mingxuan 2020-9-13
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mov bl, [BPB_SecPerClu] ;modified by mingxuan 2020-9-17
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MUL EBX
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;ADD EAX, DATA_START_SECTOR ;deleted by mingxuan 2020-9-17
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ADD EAX, [DATA_START_SECTOR] ;modified by mingxuan 2020-9-17
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MOV DWORD[ BP - DAP_SECTOR_LOW ], EAX
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;MOV BL , BYTE [BPB_SecPerClu]
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;mov bl, byte [fs:BPB_SecPerClu] ;modified by mingxuan 2020-9-13
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mov bl, byte [BPB_SecPerClu] ;modified by mingxuan 2020-9-17
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; 设置缓冲区
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MOV WORD [ BP - DAP_BUFFER_SEG ], CX
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MOV WORD [ BP - DAP_BUFFER_OFF ], OSLOADER_SEG_OFF
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_NEXT_DATA_SECTOR:
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; 读取簇中的每个扇区(内层循环)
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; 注意 : 通过检查文件大小，可以避免读取最后一个不满簇的所有大小
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call ReadSector
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; 更新地址，继续读取
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;MOV AX, WORD [BPB_BytesPerSec] ;deleted by mingxuan 2020-9-13
|
||
;mov es, BaseOfBoot ;modified by mingxuan 2020-9-13
|
||
;mov ax, word [fs:BPB_BytesPerSec] ;modified by mingxuan 2020-9-13
|
||
mov ax, word [BPB_BytesPerSec] ;modified by mingxuan 2020-9-17
|
||
|
||
ADD WORD [BP - DAP_BUFFER_OFF], ax
|
||
INC DWORD [BP - DAP_SECTOR_LOW] ; 递增扇区号
|
||
DEC BL ; 内层循环计数
|
||
|
||
JNZ _NEXT_DATA_SECTOR
|
||
|
||
;for test, added by mingxuan 2020-9-10
|
||
;call DispStr ;
|
||
;JMP $ ;for test, added by mingxuan 2020-9-10
|
||
|
||
|
||
; 更新读取下一个簇的缓冲区地址
|
||
;MOV CL, BYTE [ BPB_SecPerClu ]
|
||
;mov es, BaseOfBoot ;modified by mingxuan 2020-9-13
|
||
;mov cl, byte [fs:BPB_SecPerClu] ;modified by mingxuan 2020-9-13
|
||
mov cl, [BPB_SecPerClu] ;modified by mingxuan 2020-9-17
|
||
|
||
;MOV AX, WORD [BPB_BytesPerSec] ;deleted by mingxuan 2020-9-13
|
||
;mov es, BaseOfBoot ;modified by mingxuan 2020-9-13
|
||
;mov ax, word [fs:BPB_BytesPerSec] ;modified by mingxuan 2020-9-13
|
||
mov ax, [BPB_BytesPerSec] ;modified by mingxuan 2020-9-17
|
||
|
||
SHR AX, 4
|
||
MUL CL
|
||
ADD AX, WORD [ BP - DAP_BUFFER_SEG ]
|
||
MOV CX, AX ; 保存下一个簇的缓冲区段地址
|
||
|
||
;====================================================================
|
||
; 检查是否还有下一个簇(读取FAT表的相关信息)
|
||
; LET N = 数据簇号
|
||
; THUS FAT_BYTES = N*4 (FAT32)
|
||
; FAT_SECTOR = FAT_BYTES / BPB_BytesPerSec
|
||
; FAT_OFFSET = FAT_BYTES % BPB_BytesPerSec
|
||
;====================================================================
|
||
|
||
; 计算FAT所在的簇号和偏移
|
||
MOV EAX,DWORD [BP - CURRENT_CLUSTER]
|
||
XOR EDX,EDX
|
||
SHL EAX,2
|
||
XOR EBX,EBX
|
||
|
||
;MOV BX,WORD [ BPB_BytesPerSec ] ;deleted by mingxuan 2020-9-13
|
||
;mov es, BaseOfBoot ;modified by mingxuan 2020-9-13
|
||
; mov bx, word [fs:BPB_BytesPerSec] ;modified by mingxuan 2020-9-13
|
||
mov bx, [BPB_BytesPerSec] ;modified by mingxuan 2020-9-17
|
||
|
||
DIV EBX ; EAX = Sector EDX = Offset
|
||
|
||
; 计算FAT表的起始扇区号
|
||
; added by mingxuan 2020-9-17
|
||
;mov ebx, dword [ fs:OffsetOfActiPartStartSec ]
|
||
;add bx, word [ fs:BPB_RsvdSecCnt ]
|
||
|
||
; 设置int 13h读取的绝对扇区号
|
||
;ADD EAX, FAT_START_SECTOR ;deleted by mingxuan 2020-9-17
|
||
ADD EAX, [FAT_START_SECTOR] ;modified by mingxuan 2020-9-17
|
||
;add eax, ebx ;modified by mingxuan 2020-9-17
|
||
MOV DWORD [ BP - DAP_SECTOR_LOW ], EAX
|
||
|
||
; 设置int 13h写入内存的缓冲区地址
|
||
MOV WORD [BP - DAP_BUFFER_SEG ], 01000H
|
||
MOV WORD [BP - DAP_BUFFER_OFF ], DATA_BUF_OFF
|
||
|
||
; 读取扇区 ; 把FAT表读进内存
|
||
CALL ReadSector
|
||
|
||
; 检查下一个簇
|
||
MOV DI,DX
|
||
ADD DI,DATA_BUF_OFF
|
||
MOV EAX,DWORD[DI] ; EAX = 下一个要读的簇号
|
||
AND EAX,CLUSTER_MASK
|
||
MOV DWORD[ BP - CURRENT_CLUSTER ],EAX
|
||
CMP EAX,CLUSTER_LAST ; CX >= 0FFFFFF8H，则意味着没有更多的簇了
|
||
|
||
;for test, added by mingxuan 2020-9-10
|
||
;call DispStr ;
|
||
;JMP $ ;for test, added by mingxuan 2020-9-10
|
||
|
||
; 清屏
|
||
; for test, added by mingxuan 2020-9-15
|
||
;pusha
|
||
;mov dx, 0184fh ; 右下角: (80, 50)
|
||
;int 10h ; int 10h
|
||
;popa
|
||
|
||
|
||
JB _NEXT_DATA_CLUSTER
|
||
|
||
_RUN_LOADER:
|
||
|
||
;mov dl, [BS_DriveNum] ;deleted by mingxuan 2020-9-13
|
||
;mov es, BaseOfBoot ;modified by mingxuan 2020-9-13
|
||
;mov dl, [fs:BS_DriveNum] ;modified by mingxuan 2020-9-13
|
||
mov dl, [BS_DriveNum] ;modified by mingxuan 2020-9-17
|
||
|
||
;for test, added by mingxuan 2020-9-10
|
||
;call DispStr ;
|
||
;jmp $ ;for test 2020-9-10, mingxuan
|
||
|
||
; 清屏
|
||
; for test, added by mingxuan 2020-9-15
|
||
;pusha
|
||
;mov dx, 0184fh ; 右下角: (80, 50)
|
||
;int 10h ; int 10h
|
||
;popa
|
||
|
||
|
||
jmp OSLOADER_SEG : OSLOADER_SEG_OFF
|
||
|
||
|
||
LoaderName db "LOADER BIN" ; 第二阶段启动程序 FDOSLDR.BIN
|
||
|
||
; for display
|
||
; added by mingxuan 2020-9-4
|
||
;TestMessage: db "#" ; 27字节, 不够则用空格补齐. 序号 0
|
||
|
||
; for display
|
||
; added by mingxuan 2020-9-4
|
||
;DispStr:
|
||
; pusha
|
||
|
||
; mov ax, TestMessage
|
||
; mov bp, ax
|
||
; mov cx, 1
|
||
; mov ax, 01301h ; AH = 13, AL = 01h
|
||
; mov bx, 0007h ; 页号为0(BH = 0) 黑底白字(BL = 07h)
|
||
|
||
; int 10h ; int 10h
|
||
|
||
; popa
|
||
|
||
; ret
|
||
|
||
|
||
times 510-($-$$) db 0 ; 填充剩下的空间，使生成的二进制代码恰好为512字节
|
||
dw 0xaa55 ; 结束标志
|