Added TODO file; working on DOS installer program.

3 files changed, 136 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 5fcc5401..7ed8f22b 100644
--- a/Makefile
+++ b/Makefile
@@ -17,7 +17,7 @@
 
 NASM	= nasm
 
-all:	bootsect.bin ldlinux.sys
+all:	bootsect.bin ldlinux.sys syslinux.com
 
 ldlinux.bin: ldlinux.asm
 	$(NASM) -f bin -dHEX_TIME="`perl now.pl`" -l ldlinux.lst -o ldlinux.bin ldlinux.asm
@@ -30,6 +30,10 @@ ldlinux.sys: ldlinux.bin
 	dd if=ldlinux.bin of=ldlinux.sys  bs=512 skip=1
 	ls -l ldlinux.sys
 
+syslinux.com: syslinux.asm bootsect.bin ldlinux.sys
+	$(NASM) -f bin -l syslinux.lst -o syslinux.com syslinux.asm
+	ls -l syslinux.com
+
 clean:
 	rm -f *.bin *.lst *.sys
 
diff --git a/TODO b/TODO
new file mode 100644
index 00000000..866a46c2
--- /dev/null
+++ b/TODO
@@ -0,0 +1,3 @@
+- FAT16 support (for LS120 floppies mainly).
+- "Comboot" style boot files.
+- Booting DOS for a DOS/Linux dual rescue disk.
diff --git a/syslinux.asm b/syslinux.asm
new file mode 100644
index 00000000..84e5ef4e
--- /dev/null
+++ b/syslinux.asm
@@ -0,0 +1,128 @@
+; -*- fundamental -*- (asm-mode sucks)
+; $Id$
+; -----------------------------------------------------------------------
+;   
+;   Copyright 1998 H. Peter Anvin - All Rights Reserved
+;
+;   This program is free software; you can redistribute it and/or modify
+;   it under the terms of the GNU General Public License as published by
+;   the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+;   USA; either version 2 of the License, or (at your option) any later
+;   version; incorporated herein by reference.
+;
+; -----------------------------------------------------------------------
+
+;
+; syslinux.asm
+;
+;	DOS installer for SYSLINUX
+;
+
+		absolute 0080h
+psp_cmdlen	resb 1
+psp_cmdline	resb 127
+
+		section .text
+		org 0100h
+_start:		
+		; BUG: check DOS version
+
+;
+; Scan command line for a drive letter followed by a colon
+;
+		xor cx,cx
+		mov si,psp_cmdline
+		mov cl,[psp_cmdlen]
+		
+cmdscan1:	jcxz bad_usage			; End of command line?
+		lodsb				; Load character
+		dec cx
+		cmp al,' '			; White space
+		jbe cmdscan1
+		or al,020h			; -> lower case
+		cmp al,'a'			; Check for letter
+		jb bad_usage
+		cmp al,'z'
+		ja bad_usage
+		sub al,'a'			; Convert to zero-based index
+		mov [DriveNo],al		; Save away drive index
+
+		section .bss
+DriveNo		resb 1
+
+		section .text
+;
+; Got the leading letter, now the next character must be a colon
+;
+got_letter:	jcxz bad_usage
+		lodsb
+		dec cx
+		cmp al,':'
+		jne bad_usage
+;
+; Got the colon; the rest better be whitespace
+;
+got_colon:	jcxz got_cmdline
+		lodsb
+		dec cx
+		cmp al,' '
+		jbe got_colon
+;
+; We end up here if the command line doesn't parse
+;
+bad_usage:	mov dx,msg_unfair
+		mov ah,09h
+		int 21h
+
+		mov ax,4C01h			; Exit with error code
+		int 21h
+
+		section .data
+msg_unfair	db 'Usage: syslinux <drive>:', 0Dh, 0Ah, '$'
+
+		section .text
+;
+; Parsed the command line OK, now get to work
+;
+got_cmdline:	; BUG: check sector size == 512
+
+		mov bx,SectorBuffer
+		mov al,[DriveNo]
+		mov cx,1			; One sector
+		xor dx,dx			; Absolute sector 0
+		int 25h				; DOS absolute disk read
+		add sp,byte 2			; Remove flags from stack
+		jc disk_read_error
+		
+		; BUG: check FAT12, clustersize < 128 sectors
+
+		mov si,SectorBuffer+11		; Offset of superblock
+		mov di,BootSector+11
+		mov cx,51			; Superblock = 51 bytes
+		rep movsb			; Copy the superblock
+
+		; Write LDLINUX.SYS here (*before* writing boot sector)
+
+		mov bx,BootSector
+		mov cx,1			; One sector
+		xor dx,dx			; Absolute sector 0
+		int 26h				; DOS absolute disk write
+		add sp,byte 2			; Remove flags
+		jc disk_write_error
+
+all_done:	mov ax,4C00h			; Exit good status
+		int 21h
+
+disk_read_error:
+disk_write_error:
+		mov ax,4C01h
+		int 21h
+
+		section .data
+		align 4, db 0
+BootSector:	incbin "bootsect.bin"
+LDLinuxSYS:	incbin "ldlinux.sys"
+
+		section .bss
+		alignb 4
+SectorBuffer:	resb 512