SliTaz Repositories

     1.1 --- a/BootProg/stuff/boot16.asm	Thu May 11 15:58:49 2023 +0000
     1.2 +++ b/BootProg/stuff/boot16.asm	Fri May 12 21:35:09 2023 +0000
     1.3 @@ -11,7 +11,7 @@
     1.4  ;;                                                                          ;;
     1.5  ;;                                 Features:                                ;;
     1.6  ;;                                 ~~~~~~~~~                                ;;
     1.7 -;; - FAT12 and FAT16 supported using BIOS int 13h function 42h or 02h.      ;;
     1.8 +;; - FAT12 and/or FAT16 supported using BIOS int 13h function 42h or 02h.   ;;
     1.9  ;;                                                                          ;;
    1.10  ;; - Loads a 16-bit executable file in the MS-DOS .COM or .EXE format       ;;
    1.11  ;;   from the root directory of a disk and transfers control to it          ;;
    1.12 @@ -31,7 +31,8 @@
    1.13  ;; - Need a up to date field bpbHiddenSectors to work in a partition ;      ;;
    1.14  ;;   most formatters don't update it correcly in extended partitions.       ;;
    1.15  ;;                                                                          ;;
    1.16 -;; - Partition must fit in the first 8GB disk for CHS reads.                ;;
    1.17 +;; - Partition must fit in the first 8GB disk of the for CHS reads.         ;;
    1.18 +;;   (or 2TB for LBA reads).                                                ;;
    1.19  ;;                                                                          ;;
    1.20  ;;                                                                          ;;
    1.21  ;;                                Known Bugs:                               ;;
    1.22 @@ -93,10 +94,10 @@
    1.23  %define bx(label)       bx+label-boot
    1.24  %define si(label)       si+label-boot
    1.25  NullEntryCheck          equ     1               ; +2 bytes
    1.26 -ReadRetry               equ     1               ; +9/+10 bytes
    1.27 -LBAsupport              equ     1               ; +16 bytes
    1.28 +ReadRetry               equ     1               ; +9/+13 bytes
    1.29 +LBAsupport              equ     1               ; +18 bytes
    1.30  CHSsanityCheck          equ     1               ; +12/+16 bytes 
    1.31 -GeometryCheck           equ     1               ; +18 bytes
    1.32 +GeometryCheck           equ     1               ; +20 bytes
    1.33  CheckAttrib             equ     0               ; +6 bytes
    1.34  WaitForKey              equ     0               ; +5 bytes
    1.35  SectorOf512Bytes        equ     0               ; -4/-6 bytes
    1.36 @@ -210,7 +211,7 @@
    1.37  
    1.38  %if GeometryCheck != 0
    1.39   %if ((main-boot) & 3Fh) != 0
    1.40 -        xchg    ax, cx                  ; ax & 3Fh == 0
    1.41 +        xor     cx, cx
    1.42   %endif
    1.43          mov     ah, 8                   ; update AX,BL,CX,DX,DI, and ES registers
    1.44          int     13h                     ; may destroy SI,BP, and DS registers
    1.45 @@ -597,18 +598,19 @@
    1.46          dec     bx
    1.47          push    di
    1.48  %endif
    1.49 +        mov     si, sp
    1.50  
    1.51          xchg    ax, cx                  ; save low LBA
    1.52          xchg    ax, dx                  ; get high LBA
    1.53          cwd                             ; clear dx (LBA offset <1TB)
    1.54          idiv    word [bx(bpbSectorsPerTrack)] ; up to 8GB disks
    1.55  
    1.56 - %if CHSsanityCheck != 0
    1.57 +%if CHSsanityCheck != 0
    1.58          inc     ax
    1.59          cmp     ax, [bx(bpbHeadsPerCylinder)]
    1.60          ja      CHSoverflow
    1.61          dec     ax
    1.62 - %endif
    1.63 +%endif
    1.64          xchg    ax, cx                  ; restore low LBA, save high LBA / SPT
    1.65          idiv    word [bx(bpbSectorsPerTrack)]
    1.66                  ; ax = LBA / SPT
    1.67 @@ -637,16 +639,13 @@
    1.68   %endif
    1.69  %endif
    1.70  CHSoverflow:
    1.71 -        mov     dl, [bx(DriveNumber)]
    1.72 -                ; dl = drive no.
    1.73 -        mov     si, sp
    1.74 -%if CHSsanityCheck != 0
    1.75 - %if ReadRetry != 0 || LBAsupport != 0
    1.76 +%if CHSsanityCheck != 0 && (ReadRetry != 0 || LBAsupport != 0)
    1.77          pushf
    1.78 - %endif
    1.79  %endif
    1.80  
    1.81  ReadSectorRetry:
    1.82 +        mov     dl, [bx(DriveNumber)]
    1.83 +                ; dl = drive no.
    1.84  %if LBAsupport != 0
    1.85          mov     ah, 42h                 ; ah = 42h = extended read function no.
    1.86          int     13h                     ; extended read sectors (DL, DS:SI)