Added a workaround for broken BIOSes.

[reactos.git] / freeldr / bootsect / isoboot.asm

diff --git a/freeldr/bootsect/isoboot.asm b/freeldr/bootsect/isoboot.asm
index d4a0bc0..e3b5d6b 100644 (file)
--- a/freeldr/bootsect/isoboot.asm
+++ b/freeldr/bootsect/isoboot.asm
@@ -31,7 +31,7 @@
 ; ****************************************************************************
 
 ; Note: The Makefile builds one version with DEBUG_MESSAGES automatically.
-;%define DEBUG_MESSAGES                ; Uncomment to get debugging messages
+%define DEBUG_MESSAGES                ; Uncomment to get debugging messages
 
 
 
@@ -77,6 +77,7 @@ SECTORSIZE_LG2        equ 11                  ; 2048 bytes/sector (El Torito requirement)
 SECTORSIZE     equ (1 << SECTORSIZE_LG2)
 CR             equ 13                  ; Carriage Return
 LF             equ 10                  ; Line Feed
+retry_count    equ 6                   ; How patient are we with the BIOS?
 
 
 
@@ -130,6 +131,7 @@ relocate:
 
 
        ; Make sure the keyboard buffer is empty
+%ifdef WAIT_FOR_KEY
 .kbd_buffer_test:
        call    pollchar
        jz      .kbd_buffer_empty
@@ -179,7 +181,7 @@ relocate:
        mov     dx, 0080h
 
        jmp     0:0x7C00
-
+%endif
 
 .boot_cdrom:
        ; Save and display the boot drive number
@@ -288,7 +290,7 @@ get_fs_structures:
        call    crlf
 %endif
 
-       ; Look for the "X86" directory, and if found,
+       ; Look for the "REACTOS" directory, and if found,
        ; make it the current directory instead of the root
        ; directory.
        mov     di,isolinux_dir
@@ -316,7 +318,7 @@ get_fs_structures:
        jmp     kaboom                          ; fail boot
 
 .isolinux_opened:
-       push    si                              ; save file pointer
+       mov     di, si                          ; save file pointer
 
 %ifdef DEBUG_MESSAGES
        mov     si, filelen_msg
@@ -325,10 +327,40 @@ get_fs_structures:
        call    crlf
 %endif
 
+       mov ecx, eax                    ; calculate sector count
+       shr ecx, 11
+       test eax, 0x7FF
+       jz .full_sector
+       inc ecx
+.full_sector:
+
+%ifdef DEBUG_MESSAGES
+       mov eax, ecx
+       mov     si, filesect_msg
+       call    writemsg
+       call    writehex8
+       call    crlf
+%endif
+
+       mov eax, [di+file_sector]
+       call    writehex8
+       call    crlf
+
+       mov eax, [di+file_left]
+       call    writehex8
+       call    crlf
+
        mov     bx, 0x8000                      ; bx = load address
-       pop     si                              ; si = file pointer
+       mov     si, di                          ; restore file pointer
        mov     cx, 0xFFFF                      ; load the whole file
-       call    getfssec                        ; get the first sector
+       call    getfssec                        ; get the whole file
+
+%ifdef DEBUG_MESSAGES
+       mov     si, startldr_msg
+       call    writemsg
+       call    crlf
+%endif
+
        mov     dl, [DriveNo]                   ; dl = boot drive
        mov dh, 0                                       ; dh = boot partition
        jmp     0:0x8000                        ; jump into OSLoader
@@ -642,7 +674,8 @@ spec_query_failed:
        cmp     byte [DriveNo], dl
        je      .found_drive
 
-.still_broken: dec dx
+.still_broken:
+       dec dx
        cmp     dl, 80h
        jnb     .test_loop
 
@@ -774,11 +807,11 @@ getlinsec:
        mov bx,es
        mov [si+6],bx
        mov [si+8],eax
-.loop:
+.loop2:
        push bp                         ; Sectors left
-       cmp bp,byte 32
+       cmp bp,[MaxTransfer]
        jbe .bp_ok
-       mov bp,32
+       mov bp,[MaxTransfer]
 .bp_ok:
        mov [si+2],bp
        push si
@@ -793,13 +826,13 @@ getlinsec:
        shl ax,SECTORSIZE_LG2-4         ; 2048-byte sectors -> segment
        add [si+6],ax                   ; Advance buffer pointer
        and bp,bp
-       jnz .loop
+       jnz .loop2
        mov eax,[si+8]                  ; Next sector
        ret
 
        ; INT 13h with retry
 xint13:
-       mov     byte [RetryCount], 6
+       mov     byte [RetryCount], retry_count
 .try:
        pushad
        int     13h
@@ -809,8 +842,26 @@ xint13:
 .error:
        mov     [DiskError], ah         ; Save error code
        popad
-       dec     byte [RetryCount]
-       jnz     .try
+       dec byte [RetryCount]
+       jz .real_error
+       push ax
+       mov al,[RetryCount]
+       mov ah,[dapa+2]                 ; Sector transfer count
+       cmp al,2                        ; Only 2 attempts left
+       ja .nodanger
+       mov ah,1                        ; Drop transfer size to 1
+       jmp short .setsize
+.nodanger:
+       cmp al,retry_count-2
+       ja .again                       ; First time, just try again
+       shr ah,1                        ; Otherwise, try to reduce
+       adc ah,0                        ; the max transfer size, but not to 0
+.setsize:
+       mov [MaxTransfer],ah
+       mov [dapa+2],ah
+.again:
+       pop ax
+       jmp .try
 
 .real_error:
        mov     si, diskerr_msg
@@ -858,11 +909,11 @@ getchar:
 ; pollchar: check if we have an input character pending (ZF = 0)
 ;
 pollchar:
-               pushad
-               mov ah,1                ; Poll keyboard
-               int 16h
-               popad
-               ret
+       pushad
+       mov ah,1                ; Poll keyboard
+       int 16h
+       popad
+       ret
 
 
 
@@ -878,10 +929,11 @@ secsize_msg:      db 'Sector size appears to be ', 0
 rootloc_msg:   db 'Root directory location: ', 0
 rootlen_msg:   db 'Root directory length: ', 0
 rootsect_msg:  db 'Root directory length(sectors): ', 0
-fileloc_msg:   db 'FreeLdr.sys location: ', 0
-filelen_msg:   db 'FreeLdr.sys length: ', 0
-filesect_msg:  db 'FreeLdr.sys length(sectors): ', 0
+fileloc_msg:   db 'SETUPLDR.SYS location: ', 0
+filelen_msg:   db 'SETUPLDR.SYS length: ', 0
+filesect_msg:  db 'SETUPLDR.SYS length(sectors): ', 0
 findfail_msg:  db 'Failed to find file!', 0
+startldr_msg:  db 'Starting SETUPLDR.SYS', 0
 %endif
 
 nosecsize_msg: db 'Failed to get sector size, assuming 0800', CR, LF, 0
@@ -896,8 +948,8 @@ ondrive_str:        db ', drive ', 0
 err_bootfailed db CR, LF, 'Boot failed: press a key to retry...'
 isolinux_dir   db '\REACTOS', 0
 no_dir_msg     db 'Could not find the REACTOS directory.', CR, LF, 0
-isolinux_bin   db 'FREELDR.SYS', 0
-no_isolinux_msg        db 'Could not find the file FREELDR.SYS.', CR, LF, 0
+isolinux_bin   db 'SETUPLDR.SYS', 0
+no_isolinux_msg        db 'Could not find SETUPLDR.SYS.', CR, LF, 0
 
 ;
 ; El Torito spec packet
@@ -949,6 +1001,9 @@ dapa:              dw 16                           ; Packet size
 .lba:          dd 0                            ; LBA (LSW)
                dd 0                            ; LBA (MSW)
 
+               alignb 4, db 0
+MaxTransfer    dw 2 ;32                                ; Max sectors per transfer
+
                times 2048-($-$$) nop           ; Pad to file offset 2048