Clean up the error messages code; move some uninitialized variables to

the BSS area; build isolinux both with and without debugging messages
by default.

diff --git a/Makefile b/Makefile
index 0d800ef..f73f4d6 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -36,7 +36,7 @@ SOURCES = ldlinux.asm syslinux.asm syslinux.c copybs.asm \
          pxelinux.asm pxe.inc mbr.asm gethostip.c \
          isolinux.asm
 BTARGET = bootsect.bin ldlinux.sys ldlinux.bin ldlinux.lst \
-         pxelinux.0 mbr.bin isolinux.bin
+         pxelinux.0 mbr.bin isolinux.bin isolinux-debug.bin
 ITARGET = syslinux.com syslinux copybs.com gethostip
 DOCS    = COPYING NEWS README TODO *.doc sample
 OTHER   = Makefile bin2c.pl now.pl genstupid.pl keytab-lilo.pl version \
@@ -81,6 +81,12 @@ isolinux.bin: isolinux.asm
                -dHEXDATE="$(HEXDATE)" \
                -l isolinux.lst -o isolinux.bin isolinux.asm
 
+# Special verbose version of isolinux.bin
+isolinux-debug.bin: isolinux.asm
+       $(NASM) -f bin -dVERSION="'$(VERSION)'" -dDATE_STR="'$(DATE)'" \
+               -dHEXDATE="$(HEXDATE)" -dDEBUG_MESSAGES \
+               -l isolinux-debug.lst -o isolinux-debug.bin isolinux.asm
+
 bootsect.bin: ldlinux.bin
        dd if=ldlinux.bin of=bootsect.bin bs=512 count=1
 

diff --git a/isolinux.asm b/isolinux.asm
index 5b22f84..09426ab 100644 (file)
--- a/isolinux.asm
+++ b/isolinux.asm
@@ -19,11 +19,24 @@
 ; 
 ; ****************************************************************************
 
+; Note: The Makefile builds one version with DEBUG_MESSAGES automatically.
+; %define DEBUG_TRACERS                        ; Uncomment to get debugging tracers
+; %define DEBUG_MESSAGES               ; Uncomment to get debugging messages
+
+%ifdef DEBUG_TRACERS
+
 %macro TRACER  1
-;      call debug_tracer
-;      db %1
+       call debug_tracer
+       db %1
+%endmacro
+
+%else  ; DEBUG_TRACERS
+
+%macro TRACER  1
 %endmacro
 
+%endif ; DEBUG_TRACERS
+
 ;
 ; Some semi-configurable constants... change on your own risk.  Most are imposed
 ; by the kernel.
@@ -300,6 +313,8 @@ 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)
+FirstSecSum    resd 1                  ; Checksum of bytes 64-2048
+ImageDwords    resd 1                  ; isolinux.bin size, dwords
 FBytes         equ $                   ; Used by open/getc
 FBytes1                resw 1
 FBytes2                resw 1
@@ -323,6 +338,7 @@ ConfigFile  resw 1                  ; Socket for config file
 PktTimeout     resw 1                  ; Timeout for current packet
 KernelExtPtr   resw 1                  ; During search, final null pointer
 LocalBootType  resw 1                  ; Local boot return code
+ImageSectors   resw 1                  ; isolinux.bin size, sectors
 TextAttrBX      equ $
 TextAttribute   resb 1                 ; Text attribute for message file
 TextPage        resb 1                 ; Active display page
@@ -339,6 +355,7 @@ A20Tries    resb 1                  ; Times until giving up on A20
 FuncFlag       resb 1                  ; == 1 if <Ctrl-F> pressed
 ISOFlags       resb 1                  ; Flags for ISO directory search
 DiskError      resb 1                  ; Error code for disk I/O
+DriveNo                resb 1                  ; CD-ROM BIOS drive number
 TextColorReg   resb 17                 ; VGA color registers for text mode
 VGAFileBuf     resb FILENAME_MAX       ; Unmangled VGA image name
 VGAFileBufEnd  equ $
@@ -384,8 +401,10 @@ _start1:   mov [cs:InitStack],sp           ; Save initial stack pointer
                ; Show signs of life
                mov si,isolinux_banner
                call writestr
+%ifdef DEBUG_MESSAGES
                mov si,copyright_str
                call writestr
+%endif
 
                ;
                ; Before modifying any memory, get the checksum of bytes
@@ -408,12 +427,14 @@ initial_csum:     xor edi,edi
                shr eax,9                       ; dwords->sectors
                mov [ImageSectors],ax           ; boot file sectors
 
+               mov [DriveNo],dl
+%ifdef DEBUG_MESSAGES
                mov si,startup_msg
                call writemsg
-               mov [DriveNo],dl
                mov al,dl
                call writehex2
                call crlf
+%endif
 
                ; Now figure out what we're actually doing
                ; Note: use passed-in DL value rather than 7Fh because
@@ -427,11 +448,13 @@ initial_csum:     xor edi,edi
                cmp [sp_drive],dl               ; Should contain the drive number
                jne near spec_query_failed
 
+%ifdef DEBUG_MESSAGES
                mov si,spec_ok_msg
                call writemsg
                mov al,byte [sp_drive]
                call writehex2
                call crlf
+%endif
 
 found_drive:
                ; Get drive information
@@ -447,11 +470,17 @@ found_drive:
 params_ok:
                ; Check for the sector size (should be 2048, but
                ; some BIOSes apparently think we're 512-byte media)
+               ;
+               ; FIX: We need to check what the proper behaviour
+               ; is for getlinsec when the BIOS thinks the sector
+               ; size is 512!!!  For that, we need such a BIOS, though...
+%ifdef DEBUG_MESSAGES
                mov si,secsize_msg
                call writemsg
                mov ax,[dp_secsize]
                call writehex4
                call crlf
+%endif
 
 load_image:
                ; Some BIOSes apparently have limitations on the size 
@@ -461,10 +490,12 @@ load_image:
 
                mov eax,[bi_file]               ; Address of code to load
                inc eax                         ; Don't reload bootstrap code
+%ifdef DEBUG_MESSAGES
                mov si,offset_msg
                call writemsg
                call writehex8
                call crlf
+%endif
 
                ; Just in case some BIOSes have problems with
                ; segment wraparound, use the normalized address
@@ -472,6 +503,7 @@ load_image:
                mov es,bx
                xor bx,bx
                mov bp,[ImageSectors]
+%ifdef DEBUG_MESSAGES
                push ax
                mov si,size_msg
                call writemsg
@@ -479,13 +511,16 @@ load_image:
                call writehex4
                call crlf
                pop ax
+%endif
                call getlinsec
 
-               mov ax,ds
-               mov es,ax
+               push ds
+               pop es
 
+%ifdef DEBUG_MESSAGES
                mov si,loaded_msg
                call writemsg
+%endif
 
                ; Verify the checksum on the loaded image.
 verify_image:
@@ -509,11 +544,14 @@ verify_image:
                je integrity_ok
 
                mov si,checkerr_msg
-               call writestr
+               call writemsg
+               jmp kaboom
 
 integrity_ok:
+%ifdef DEBUG_MESSAGES
                mov si,allread_msg
                call writemsg
+%endif
                jmp all_read                    ; Jump to main code
 
                ; INT 13h, AX=4B01h, DL=7Fh failed.  Try to scan the
@@ -744,30 +782,30 @@ isolinux_banner   db CR, LF, 'ISOLINUX ', version_str, ' ', date, ' ', 0
 copyright_str   db ' Copyright (C) 1994-', year, ' H. Peter Anvin'
                db CR, LF, 0
 isolinux_str   db 'isolinux: ', 0
+%ifdef DEBUG_MESSAGES
 startup_msg:   db 'Starting up, DL = ', 0
 spec_ok_msg:   db 'Loaded spec packet OK, drive = ', 0
-spec_err_msg:  db 'Loading spec packet failed, trying to wing it...', CR, LF, 0
-maybe_msg:     db 'Found something at drive = ', 0
 secsize_msg:   db 'Sector size appears to be ', 0
-nosecsize_msg: db 'Failed to get sector size, assuming 0800', CR, LF, 0
-nothing_msg:   db 'Failed to access CD-ROM device; boot failed.', CR, LF, 0
-alright_msg:   db 'Looks like it might be right, continuing...', CR, LF, 0
 offset_msg:    db 'Loading main image from LBA = ', 0
 size_msg:      db 'Sectors to load = ', 0
 loaded_msg:    db 'Loaded boot image, verifying...', CR, LF, 0
 verify_msg:    db 'Image checksum verified.', CR, LF, 0
-checkerr_msg:  db 'Load checksum error, goodbye...', CR, LF, 0
+allread_msg    db 'Main image read, jumping to main code...', CR, LF, 0
+%endif
+spec_err_msg:  db 'Loading spec packet failed, trying to wing it...', CR, LF, 0
+maybe_msg:     db 'Found something at drive = ', 0
+alright_msg:   db 'Looks like it might be right, continuing...', CR, LF, 0
+nosecsize_msg: db 'Failed to get sector size, assuming 0800', CR, LF, 0
 diskerr_msg:   db 'Disk error ', 0
 ondrive_str:   db ', drive ', 0
-allread_msg    db 'Main image read, jumping to main code...', CR, LF, 0
+nothing_msg:   db 'Failed to access CD-ROM device; boot failed.', CR, LF, 0
+checkerr_msg:  db 'Image checksum error, sorry...', CR, LF, 0
+
+err_bootfailed db CR, LF, 'Boot failed: press a key to retry...'
+bailmsg                equ err_bootfailed
 crlf_msg       db CR, LF, 0
 
                alignb 8, db 0
-FirstSecSum:   dd 0                            ; Checksum of bytes 64-2048
-ImageDwords:   dd 0                            ; image.bin size, dwords
-ImageSectors:  dw 0                            ; image.bin size, sectors
-DriveNo:       db 0
-
 ;
 ; El Torito spec packet
 ;
@@ -855,6 +893,12 @@ not_vga:
                ; Patch the writechr routine to point to the full code
                mov word [writechr+1], writechr_full-(writechr+3)
 
+; Tell the user we got this far...
+%ifndef DEBUG_MESSAGES                 ; Gets messy with debugging on
+               mov si,copyright_str
+               call writestr
+%endif
+
 ; Test tracers
                TRACER 'T'
                TRACER '>'
@@ -4084,8 +4128,6 @@ err_notdos        db ': attempted DOS system call', CR, LF, 0
 err_comlarge   db 'COMBOOT image too large.', CR, LF, 0
 err_bootsec    db 'Invalid or corrupt boot sector image.', CR, LF, 0
 err_a20                db CR, LF, 'A20 gate not responding!', CR, LF, 0
-err_bootfailed db CR, LF, 'Boot failed: press a key to retry, or wait for reset...', CR, LF, 0
-bailmsg                equ err_bootfailed
 notfound_msg   db 'not found', CR, LF, 0
 localboot_msg  db 'Booting from local disk...', CR, LF, 0
 cmdline_msg    db 'Command line: ', CR, LF, 0