new indentation style

[BOS.git] / boot / BOS_boot.asm

diff --git a/boot/BOS_boot.asm b/boot/BOS_boot.asm
index a7a5c1259eafdc5a1ef0287f1d25926fe71e2ff7..8fde3a311cb35b04a62d98f287fa3d63ce5574f7 100755 (executable)
--- a/boot/BOS_boot.asm
+++ b/boot/BOS_boot.asm
@@ -4,282 +4,270 @@
 ;  - FAT12 compatible.                                       ;\r
 ;  - Loads a binary file from the floppy.                    ;\r
 ;                                                            ;\r
 ;  - FAT12 compatible.                                       ;\r
 ;  - Loads a binary file from the floppy.                    ;\r
 ;                                                            ;\r

+;     16-bit mem map  (seg:off)                              ;\r
+;------------------------------------------------------------;\r
+;  0x0000:0x0000 -> 0x0000:0x0500  BIOS stuff                ;\r
+;  0x0000:0x0500 -> 0x0000:0x2100  FAT12 rootdir             ;\r
+;  0x0000:0x2100 -> 0x0000:0x3300  FAT for FAT12             ;\r
+;  0x0000:0x3300 -> 0x0000:0x6c00  14,25kb free space        ;\r
+;  0x0000:0x6c00 -> 0x0000:0x7400  IDT, 256 descriptors      ;\r
+;  0x0000:0x7400 -> 0x0000:0x7c00  GDT, 256 descriptors      ;\r
+;  0x0000:0x7c00 -> 0x0000:0x7e00  bootsector                ;\r
+;  0x0000:0x7e00 <- 0x0000:0x8000  512b stack for boot       ;\r
+;  0x0000:0x8000 -> 0x9000:0xffff  608kb kernel/free space   ;\r
+;  0xA000:0x0000 -> .............  VGA mem etc.              ;\r

 ;------------------------------------------------------------;\r
 ;------------------------------------------------------------;\r

-\r
-; TODO:\r
-;  as i moved some 16-bit stuff to the kernel, i now got\r
-;  space to do proper testing (for data-area etc),\r
-;  fix that...\r
-;\r
-; TODO2:\r
-;  find out why this crap takes ages to load the kernel.. :S\r
-\r
-\r
-;\r
-;     16-bit mem map  (seg:off)\r
-;  0x0000:0x0000 -> 0x0000:0x0500  BIOS stuff\r
-;  0x0000:0x0500 -> 0x0000:0x2100  FAT12 rootdir\r
-;  0x0000:0x2100 -> 0x0000:0x3300  FAT for FAT12\r
-;  0x0000:0x3300 -> 0x0000:0x6c00  14,25kb free space\r
-;  0x0000:0x6c00 -> 0x0000:0x7400  IDT, 256 descriptors\r
-;  0x0000:0x7400 -> 0x0000:0x7c00  GDT, 256 descriptors\r
-;  0x0000:0x7c00 -> 0x0000:0x7e00  bootsector\r
-;  0x0000:0x7e00 <- 0x0000:0x8000  512b stack for boot\r
-;  0x0000:0x8000 -> 0x9000:0xffff  608kb kernel/free space\r
-;;;;  0x0000:0x7e00 <- 0x0000:0xffff  ~32,5kb stack for boot\r
-;;;;  0x1000:0x0000 -> 0x9000:0xffff  576kb kernel/free space\r
-;  0xA000:0x0000 -> .............  VGA mem etc.\r

 \r
 use16\r
 org 0x7C00\r
 \r
 boot:\r
 \r
 use16\r
 org 0x7C00\r
 \r
 boot:\r

-         jmp     short start\r
-         nop\r
+        jmp    short start\r
+        nop\r

 \r
 ;------------------------------------------;\r
 ;  Standard BIOS Parameter Block, "BPB".   ;\r
 ;------------------------------------------;\r
 \r
 ;------------------------------------------;\r
 ;  Standard BIOS Parameter Block, "BPB".   ;\r
 ;------------------------------------------;\r

-      bpbOEM          db  'BOS 0.04'\r
-         bpbSectSize     dw  512\r
-         bpbClustSize    db  1\r
-         bpbReservedSec  dw  1\r
-         bpbFats             db  2\r
-         bpbRootSize     dw  224\r
-         bpbTotalSect    dw  2880\r
-         bpbMedia            db  240\r
-         bpbFatSize      dw  9\r
-         bpbTrackSect    dw  18\r
-         bpbHeads            dw  2\r
-         bpbHiddenSect   dd  0\r
-         bpbLargeSect    dd  0\r
-     ;---------------------------------;\r
-     ;  extended BPB for FAT12/FAT16   ;\r
-     ;---------------------------------;\r
-         bpbDriveNo      db  0\r
-         bpbReserved     db  0\r
-         bpbSignature    db  41                      ; 0 = nothing more. 41 = three more (below)..\r
-         bpbID               dd  1\r
-         bpbVolumeLabel  db  'BOOT FLOPPY'\r
-         bpbFileSystem   db  'FAT12   '\r
+    bpbOEM          db  'BOS 0.04'\r
+    bpbSectSize     dw  512\r
+    bpbClustSize    db  1\r
+    bpbReservedSec  dw  1\r
+    bpbFats         db  2\r
+    bpbRootSize     dw  224\r
+    bpbTotalSect    dw  2880\r
+    bpbMedia        db  240\r
+    bpbFatSize      dw  9\r
+    bpbTrackSect    dw  18\r
+    bpbHeads        dw  2\r
+    bpbHiddenSect   dd  0\r
+    bpbLargeSect    dd  0\r
+    ;---------------------------------;\r
+    ;  extended BPB for FAT12/FAT16   ;\r
+    ;---------------------------------;\r
+    bpbDriveNo      db  0\r
+    bpbReserved     db  0\r
+    bpbSignature    db  41                            ; 0 = end. 41 = three more.\r
+    bpbID           dd  1\r
+    bpbVolumeLabel  db  'BOOT FLOPPY'\r
+    bpbFileSystem   db  'FAT12   '\r

 \r
 \r
 ;----------------------------------------;\r
 ;   starting point of bootsector code    ;\r
 ;----------------------------------------;\r
 start:\r
 \r
 \r
 ;----------------------------------------;\r
 ;   starting point of bootsector code    ;\r
 ;----------------------------------------;\r
 start:\r

-         cli\r
-\r
-         xor     ax, ax                              ; initialize all the necessary\r
-         mov     ds, ax                              ; registers.\r
-         mov     es, ax\r
-         mov     ss, ax\r
-         mov     sp, 0x8000                          ; Stack..\r
-\r
-         mov     [bpbDriveNo], dl\r
-\r
-         sti\r
-\r
-\r
-;----------------------------------;\r
-;   clear screen and print some    ;\r
-;----------------------------------;\r
-         mov     ax, 3                               ; Set mode 0x03\r
-         int     0x10\r
-\r
-         mov     bp, loading                         ; Print loading message.\r
-         mov     ax, 0x1301\r
-         mov     bx, 7\r
-         mov     cx, 12\r
-         mov     dx, 0x0102\r
-         int     0x10\r
-\r
-         mov     bl, 2                               ; Set cursor.\r
-         mov     ah, 2\r
-         mov     dx, 0x0201\r
-         int     0x10\r
-\r
-         mov     ah, 9                               ; Print 14 green dots.\r
-         mov     al, '.'\r
-         mov     cx, 14\r
-         int     0x10\r
-\r
-\r
-;---------------------------;\r
-;    load FAT and root      ;\r
-;---------------------------;\r
-         mov     di, 0x0050                          ; Load the root to\r
-         mov     ax, 19                              ; 0x0000:0x0500 (0x500/0x10)\r
-         mov     cx, 14\r
-         call    read_sectors\r
-\r
-         mov     di, 0x0210                          ; Load the fat to\r
-         mov     ax, 1                               ; 0x0000:0x2100\r
-         mov     cx, 9\r
-         call    read_sectors\r
-\r
-\r
-     ;------------------------;\r
-     ;  search for the file   ;\r
-     ;------------------------;\r
-         mov     dx, [bpbRootSize]\r
-         mov     bx, 0x0500\r
-     filesearch:\r
-         cld\r
-         mov     si, filename\r
-         mov     cx, 11\r
-         mov     di, bx\r
-         repe    cmpsb\r
-         je      found\r
-         add     bx, 32\r
-         dec     dx\r
-         jz      error\r
-         jmp     filesearch\r
+        cli\r
+\r
+        xor    ax, ax                                 ; initialize all the necessary\r
+        mov    ds, ax                                 ; registers.\r
+        mov    es, ax\r
+        mov    ss, ax\r
+        mov    sp, 0x8000                             ; Stack..\r
+\r
+        mov    [bpbDriveNo], dl\r
+\r
+        sti\r
+\r
+\r
+    ;----------------------------------;\r
+    ;   clear screen and print some    ;\r
+    ;----------------------------------;\r
+        mov    ax, 3                                  ; Set mode 0x03\r
+        int    0x10\r
+\r
+        mov    bp, loading                            ; Print loading message.\r
+        mov    ax, 0x1301\r
+        mov    bx, 7\r
+        mov    cx, 12\r
+        mov    dx, 0x0102\r
+        int    0x10\r
+\r
+        mov    bl, 2                                  ; Set cursor.\r
+        mov    ah, 2\r
+        mov    dx, 0x0201\r
+        int    0x10\r
+\r
+        mov    ah, 9                                  ; Print 14 green dots.\r
+        mov    al, '.'\r
+        mov    cx, 14\r
+        int    0x10\r
+\r
+\r
+    ;---------------------------;\r
+    ;    load FAT and root      ;\r
+    ;---------------------------;\r
+        mov    di, 0x0050                             ; Load the root to\r
+        mov    ax, 19                                 ; 0x0000:0x0500 (0x500/0x10)\r
+        mov    cx, 14\r
+        call   read_sectors\r
+\r
+        mov    di, 0x0210                             ; Load the fat to\r
+        mov    ax, 1                                  ; 0x0000:0x2100\r
+        mov    cx, 9\r
+        call   read_sectors\r
+\r
+\r
+    ;------------------------;\r
+    ;  search for the file   ;\r
+    ;------------------------;\r
+        mov    dx, [bpbRootSize]\r
+        mov    bx, 0x0500\r
+    .filesearch:\r
+        cld\r
+        mov    si, filename\r
+        mov    cx, 11\r
+        mov    di, bx\r
+        repe   cmpsb\r
+        je     found\r
+        add    bx, 32\r
+        dec    dx\r
+        jz     error\r
+        jmp    .filesearch\r

 \r
 \r
 ;-----------------------------------;\r
 ;      variables & functions        ;\r
 ;-----------------------------------;\r
 \r
 \r
 ;-----------------------------------;\r
 ;      variables & functions        ;\r
 ;-----------------------------------;\r

-         loading         db  'Starting BOS'\r
-         filename        db  'KERNEL  SYS'\r
-         failure         db  'Read error!'\r
-\r
-\r
-     ;-----------------------------------------------;\r
-     ;   read a number of sectors (one at a time)    ;\r
-     ;-----------------------------------------------;\r
-     ;  in:                                          ;\r
-     ;    di = segment to save at                    ;\r
-     ;    ax = sector to read                        ;\r
-     ;    cx = number of sectors                     ;\r
-     ;  out:                                         ;\r
-     ;    di = updated (added for next read)         ;\r
-     ;    ax = updated (added for next read)         ;\r
-     ;-----------------------------------------------;\r
-     read_sectors:\r
-         pusha\r
-         mov     bl, byte [bpbTrackSect]             ; bl = number of sectors per track\r
-         div     bl                                  ; al = ax / bl\r
-         mov     cl, ah                              ; cl = real sector number\r
-         add     cl, 1\r
-\r
-         xor     ah, ah                              ; del the rest of the div before\r
-         mov     bl, byte [bpbHeads]                 ; bl = number of heads\r
-         div     bl                                  ; ah = rest of ( ax / bx ), al = ax / bx\r
-         mov     ch, al                              ; ch = number of track\r
-         mov     dh, ah                              ; dh = the head number\r
-\r
-         mov     ax, cx                              ; save cx in ax\r
-         mov     cx, 6                               ; try it 6 times\r
-     .next_try:\r
-         push    es\r
-         push    cx\r
-         mov     cx, ax                              ; restore cx\r
-         push    cx\r
-\r
-         xor     ax, ax\r
-         mov     dl, [bpbDriveNo]                    ; reset drive\r
-         push    dx\r
-         int     0x13\r
-         jc      .failed\r
-\r
-         pop     dx\r
-         pop     cx\r
-         xor     bx, bx\r
-         mov     es, di\r
-         mov     ax, 0x0201                          ; function 2, 1 sector\r
-         int     0x13\r
-         jnc     .ok                                 ; if it was ok, check next..\r
-\r
-     .failed:\r
-         pop     dx\r
-         pop     ax\r
-\r
-         pop     cx\r
-         pop     es\r
-         loop    .next_try                           ; else try once again if there is an error\r
-         jmp     error                               ; if cx = 0 and the read operation failed, halt\r
-     .ok:\r
-         pop     cx                                  ; from the next_try loop\r
-         pop     es\r
-         popa\r
-         add     di, 32                              ; add 32 (512/16) to segment\r
-         inc     ax                                  ; add sector counter\r
-         loop    read_sectors\r
-         ret\r
-\r
-\r
-     ;----------------------------------------------------;\r
-     ;  show a message and wait for a key before reboot   ;\r
-     ;----------------------------------------------------;\r
-     error:\r
-         mov     bp, failure\r
-         mov     ax, 0x1301\r
-         mov     bx, 4\r
-         mov     cx, 11\r
-         mov     dx, 0x0401\r
-         int     0x10\r
-\r
-         mov     ah, 0\r
-         int     0x16\r
-         int     0x19\r
+    loading    db  'Starting BOS'\r
+    filename   db  'KERNEL  SYS'\r
+    failure    db  'Read error!'\r
+\r
+\r
+;-----------------------------------------------;\r
+;   read a number of sectors (one at a time)    ;\r
+;-----------------------------------------------;\r
+;  in:                                          ;\r
+;    di = segment to save at                    ;\r
+;    ax = sector to read                        ;\r
+;    cx = number of sectors                     ;\r
+;  out:                                         ;\r
+;    di = updated (added for next read)         ;\r
+;    ax = updated (added for next read)         ;\r
+;-----------------------------------------------;\r
+read_sectors:\r
+        pusha\r
+        mov    bl, byte [bpbTrackSect]                ; bl = number of sectors per track\r
+        div    bl                                     ; al = ax / bl\r
+        mov    cl, ah                                 ; cl = real sector number\r
+        add    cl, 1\r
+\r
+        xor    ah, ah                                 ; del the rest of the div before\r
+        mov    bl, byte [bpbHeads]                    ; bl = number of heads\r
+        div    bl                                     ; ah = rest of ( ax / bx ), al = ax / bx\r
+        mov    ch, al                                 ; ch = number of track\r
+        mov    dh, ah                                 ; dh = the head number\r
+\r
+        mov    ax, cx                                 ; save cx in ax\r
+        mov    cx, 6                                  ; try it 6 times\r
+    .next_try:\r
+        push   es\r
+        push   cx\r
+        mov    cx, ax                                 ; restore cx\r
+        push   cx\r
+\r
+        xor    ax, ax\r
+        mov    dl, [bpbDriveNo]                       ; reset drive\r
+        push   dx\r
+        int    0x13\r
+        jc     .failed\r
+\r
+        pop    dx\r
+        pop    cx\r
+        xor    bx, bx\r
+        mov    es, di\r
+        mov    ax, 0x0201                             ; function 2, 1 sector\r
+        int    0x13\r
+        jnc    .ok                                    ; if it was ok, check next..\r
+\r
+    .failed:\r
+        pop    dx\r
+        pop    ax\r
+\r
+        pop    cx\r
+        pop    es\r
+        loop   .next_try                              ; else try once again if there is an error\r
+        jmp    error                                  ; if cx = 0 and the read operation failed, halt\r
+    .ok:\r
+        pop    cx                                     ; from the next_try loop\r
+        pop    es\r
+        popa\r
+        add    di, 32                                 ; add 32 (512/16) to segment\r
+        inc    ax                                     ; add sector counter\r
+        loop   read_sectors\r
+        ret\r
+\r
+\r
+;----------------------------------------------------;\r
+;  show a message and wait for a key before reboot   ;\r
+;----------------------------------------------------;\r
+error:\r
+        mov    bp, failure\r
+        mov    ax, 0x1301\r
+        mov    bx, 4\r
+        mov    cx, 11\r
+        mov    dx, 0x0401\r
+        int    0x10\r
+\r
+        mov    ah, 0\r
+        int    0x16\r
+        int    0x19\r

 \r
 \r
 ;-----------------------------------;\r
 ;   the file is found, load it.     ;\r
 ;-----------------------------------;\r
 found:\r
 \r
 \r
 ;-----------------------------------;\r
 ;   the file is found, load it.     ;\r
 ;-----------------------------------;\r
 found:\r

-         mov     bp, [bx+26]                         ; bp=cluster number from directory entry\r
-         mov     di, 0x800                           ; 1000 (segment)\r
-\r
-     .next_block:\r
-         xor     cx, cx\r
-         mov     cl, [bpbClustSize]                  ; reset sector count to 1 cluster\r
-         mov     si, bp                              ; si=next should-be cluster for\r
-                                                     ; contiguous reads\r
-     .next_contiguous:\r
-         mov     ax, 3                               ; 3\r
-         mul     si                                  ; multiply cluster number by 3\r
-         shr     ax, 1                               ; divide by two\r
-         mov     bx, ax\r
-         mov     ax, word [(0x2100+bx)]              ; ax=FAT element with junk\r
-         jc      .odd_cluster                        ; jump if the value was odd\r
-         and     ax, 0x0FFF                          ; leave only lower 12 bits\r
-         jmp     .got_cluster                        ; got it\r
-     .odd_cluster:\r
-         shr     ax, 4                               ; (leave only bits 4-15)\r
-\r
-     .got_cluster:\r
-         inc     si                                  ; si=current cluster+1\r
-         cmp     ax, si                              ; next cluster=current cluster+1?\r
-         jne     .force_read                         ; is it still contiguous?\r
-\r
-         add     cl, [bpbClustSize]                  ; increase sector count by 1 cluster\r
-         adc     ch, 0                               ; add cf+0 to ch\r
-         jmp     .next_contiguous\r
-\r
-     .force_read:\r
-         xchg    bp, ax                              ; ax=bp (base cluster), bp=new cluster\r
-         dec     ax                                  ; decrease by 2 to get the actual...\r
-         dec     ax                                  ; ...cluster number\r
-\r
-         movzx   dx, byte [bpbClustSize]\r
-         mul     dx                                  ; multiply by sectors per cluster\r
-         add     ax, 33                              ; add data-area location (33)\r
-         call    read_sectors\r
-\r
-         cmp     bp, 0x0FF8                          ; is the new cluster EOF (FF8-FFF)?\r
-         jb      .next_block                         ; if not, read next block\r
+        mov    bp, [bx+26]                            ; bp = cluster from dir entry\r
+        mov    di, 0x0800                             ; 800 (segment)\r
+\r
+    .next_block:\r
+        xor    cx, cx\r
+        mov    cl, [bpbClustSize]                     ; reset sector count to 1 cluster\r
+        mov    si, bp                                 ; si = next should-be cluster for\r
+                                                      ; contiguous reads\r
+    .next_contiguous:\r
+        mov    ax, 3\r
+        mul    si                                     ; multiply cluster number by 3\r
+        shr    ax, 1                                  ; divide by two\r
+        mov    bx, ax\r
+        mov    ax, word [(0x2100+bx)]                 ; ax = FAT element with junk\r
+        jc     .odd_cluster                           ; jump if the value was odd\r
+        and    ax, 0x0FFF                             ; leave only lower 12 bits\r
+        jmp    .got_cluster                           ; got it\r
+    .odd_cluster:\r
+        shr    ax, 4                                  ; (leave only bits 4-15)\r
+\r
+    .got_cluster:\r
+        inc    si                                     ; si = current cluster+1\r
+        cmp    ax, si                                 ; next cluster = current cluster+1?\r
+        jne    .force_read                            ; is it still contiguous?\r
+\r
+        add    cl, [bpbClustSize]                     ; increase sector count by 1 cluster\r
+        adc    ch, 0                                  ; add cf + 0 to ch\r
+        jmp    .next_contiguous\r
+\r
+    .force_read:\r
+        xchg   bp, ax                                 ; ax = bp (base cluster), bp = new cluster\r
+        dec    ax                                     ; decrease by 2 to get the actual...\r
+        dec    ax                                     ; ...cluster number\r
+\r
+        movzx  dx, byte [bpbClustSize]\r
+        mul    dx                                     ; multiply by sectors per cluster\r
+        add    ax, 33                                 ; add data-area location (33)\r
+        call   read_sectors\r
+\r
+        cmp    bp, 0x0FF8                             ; is the new cluster EOF (FF8-FFF)?\r
+        jb     .next_block                            ; if not, read next block\r

 \r
 ;-----------------------;\r
 ;  the file is loaded   ;\r
 ;-----------------------;\r
 quit:\r
 \r
 ;-----------------------;\r
 ;  the file is loaded   ;\r
 ;-----------------------;\r
 quit:\r

-         jmp     0x0000:0x8000                       ; jump to loaded file (64kb in mem)\r
+        jmp    0x0000:0x8000                          ; jump to loaded file (64kb in mem)\r

 \r
 \r
 ;-------------------------------------;\r
 ; set the BOOT-signature at byte 510. ;\r
 ;-------------------------------------;\r
 \r
 \r
 ;-------------------------------------;\r
 ; set the BOOT-signature at byte 510. ;\r
 ;-------------------------------------;\r

-         rb boot+512-2-$\r
-         dw 0xAA55
\ No newline at end of file
+        rb boot+512-2-$\r
+        dw 0xAA55
\ No newline at end of file