xbs_vgabuf equ trackbufsize
xbs_vgatmpbuf equ 2*trackbufsize
+ struc dir_t
+dir_lba resd 1 ; Directory start (LBA)
+dir_len resd 1 ; Length in bytes
+dir_clust resd 1 ; Length in clusters
+ endstruc
+
absolute 5000h ; Here we keep our BSS stuff
VKernelBuf: resb vk_size ; "Current" vkernel
alignb 4
HiLoadAddr resd 1 ; Address pointer for high load loop
HighMemSize resd 1 ; End of memory pointer (bytes)
KernelSize resd 1 ; Size of kernel (bytes)
-RootDir resd 1 ; Root directory location (LBA)
-RootDirLen resd 1 ; Root directory length
-RootDirClust resd 1 ; Root directory length in clusters
-CurDir resd 1 ; Current directory location (LBA)
-CurDirLen resd 1 ; Current directory length
-CurDirClust resd 1 ; Current directory length in clusters
-SavedSSSP resw 1 ; Our SS:SP while running a COMBOOT image
+RootDir resb dir_t_size ; Root directory
+CurDir resb dir_t_size ; Current directory
+SavedSSSP resd 1 ; Our SS:SP while running a COMBOOT image
+InitStack resd 1 ; Initial stack pointer (SS:SP)
FBytes equ $ ; Used by open/getc
FBytes1 resw 1
FBytes2 resw 1
bi_csum: dd 0xdeadbeef ; Checksum of boot file
bi_reserved: times 10 dd 0xdeadbeef ; Reserved
-_start1: xor ax,ax
+_start1: mov [cs:InitStack],sp ; Save initial stack pointer
+ mov ax,ss
+ mov [cs:InitStack+2],ax
+ xor ax,ax
mov ss,ax
mov sp,_start ; Set up stack
mov ds,ax
mov si,dbg_rootdir_msg ; ***
call writemsg ; ***
mov eax,[trackbuf+156+2]
- mov [RootDir],eax
- mov [CurDir],eax
+ mov [RootDir+dir_lba],eax
+ mov [CurDir+dir_lba],eax
call writehex8 ; ***
call crlf ; ***
mov eax,[trackbuf+156+10]
- mov [RootDirLen],eax
- mov [CurDirLen],eax
+ mov [RootDir+dir_len],eax
+ mov [CurDir+dir_len],eax
add eax,SECTORSIZE-1
shr eax,SECTORSIZE_LG2
- mov [RootDirClust],eax
- mov [CurDirClust],eax
+ mov [RootDir+dir_clust],eax
+ mov [CurDir+dir_clust],eax
; Look for an "isolinux" directory, and if found,
; make it the current directory instead of the root
mov al,02h ; Search for a directory
call searchdir_iso
jz .no_isolinux_dir
-
- mov [CurDirLen],eax
- mov eax,[si+file_sector]
- mov [CurDir],eax
+ mov [CurDir+dir_len],eax
mov eax,[si+file_left]
- mov [CurDirClust],eax
-
- xor eax,eax
- mov [si+file_sector],eax ; Free this file pointer entry
-
+ mov [CurDir+dir_clust],eax
+ push si
+ mov si,dbg_isodir_msg ; ***
+ call writemsg ; ***
+ pop si
+ xor eax,eax ; Free this file pointer entry
+ xchg eax,[si+file_sector]
+ mov [CurDir+dir_lba],eax
+ call writehex8 ; ***
+ call crlf ; ***
.no_isolinux_dir:
;
.badness: jmp short .badness
;
-; Boot to the local disk by returning the appropriate PXE magic.
-; AX contains the appropriate return code.
+; Boot a specified local disk. AX specifies the BIOS disk number; or
+; 0xFFFF in case we should execute INT 18h ("next device.")
;
local_boot:
+ call vgaclearmode
lss sp,[cs:Stack] ; Restore stack pointer
- pop ds ; Restore DS
- mov [LocalBootType],ax
+ xor dx,dx
+ mov ds,dx
+ mov es,dx
+ mov fs,dx
+ mov gs,dx
mov si,localboot_msg
call writestr
- ; Restore the environment we were called with
- pop gs
- pop fs
- pop es
- pop ds
- popfd
- popad
- mov ax,[cs:LocalBootType]
- retf ; Return to PXE
+ cmp ax,-1
+ je .int18
+
+ ; Load boot sector from the specified BIOS device and jump to it.
+ mov dl,al
+ xor dh,dh
+ push dx
+ xor ax,ax ; Reset drive
+ call xint13
+ mov ax,0201h ; Read one sector
+ mov cx,0001h ; C/H/S = 0/0/1 (first sector)
+ mov bx,trackbuf
+ call xint13
+ pop dx
+ cli ; Abandon hope, ye who enter here
+ mov si,trackbuf
+ mov di,07C00h
+ mov cx,512 ; Probably overkill, but should be safe
+ rep movsd
+ lss sp,[cs:InitStack]
+ jmp 0:07C00h ; Jump to new boot sector
+
+.int18:
+ int 18h ; Hope this does the right thing...
+ jmp kaboom ; If we returned, oh boy...
;
; 32-bit bcopy routine for real mode
pop es ; ES = DS
call allocate_file ; Temporary file structure for directory
jnz .failure
- mov si,bx
- mov eax,[RootDirClust]
+ mov si,CurDir
+ cmp byte [di],'/' ; If filename begins with slash
+ jne .not_rooted
+ inc di ; Skip leading slash
+ mov si,RootDir ; Reference root directory instead
+.not_rooted:
+ mov eax,[si+dir_clust]
mov [bx+file_left],eax
- mov eax,[RootDir]
+ mov eax,[si+dir_lba]
mov [bx+file_sector],eax
- mov edx,[RootDirLen]
+ mov edx,[si+dir_len]
.getsome:
; Get a chunk of the directory
cmp al,33
jb .next_sector
TRACER 'c'
- mov al,[si+25]
- xor al,[ISOFlags]
- test al, byte 8Eh ; Unwanted file attributes!
+ mov cl,[si+25]
+ xor cl,[ISOFlags]
+ test cl, byte 8Eh ; Unwanted file attributes!
jnz .not_file
pusha
movzx cx,byte [si+32] ; File identifier length
mov ax,640
div cl ; Compute char rows per screen
mov dl,al
+ dec al
mov [VidRows],al
mov ax,1121h ; Set user character table
int 10h
pushfd
pushad
mov bh,[TextPage]
+ push ax
mov ah,03h ; Read cursor position
int 10h
+ pop ax
cmp al,8
je .bs
cmp al,13
int 10h
mov [UsingVGA], byte 1
- mov [VidCols], byte 80 ; Always 80 chars/screen
+ mov [VidCols], byte 79 ; Always 80 chars/screen
mov [TextPage], byte 0 ; Always page 0
mov cx,[VGAFontSize]
mov ax,640
div cl
+ dec al ; VidRows is stored -1
mov [VidRows],al
mov dl,al
mov bp,vgafontbuf
crff_msg db CR, FF, 0
default_str db 'default', 0
default_len equ ($-default_str)
-isolinux_dir db 'isolinux', 0
+isolinux_dir db '/isolinux', 0
isolinux_cfg db 'isolinux.cfg', 0
dbg_rootdir_msg db 'Root directory at LBA = ', 0
+dbg_isodir_msg db 'isolinux directory at LBA = ', 0
dbg_config_msg db 'About to load config file...', CR, LF, 0
dbg_configok_msg db 'Configuration file opened...', CR, LF, 0
;
projects / platform / upstream / syslinux.git / commitdiff