Macroize the generation of the "insufficient DOS RAM string";

Actually use the 1000h segment instead of letting it go to waste;
Set comboot_seg == real_mode_seg to save 40K

6 files changed, 86 insertions, 31 deletions

diff --git a/NEWS b/NEWS
index ff85afc4..00663780 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,12 @@ Starting with 1.47, changes marked with SYSLINUX/PXELINUX/ISOLINUX
 apply to that specific program only; other changes apply to all of
 them.
 
+Changes in 2.04:
+	* ALL: Reclaim even more low memory by observing that
+	comboot_seg == real_mode_seg is perfectly fine, and by the
+	fact that the 1000h segment managed to get unused in all
+	derivatives...
+
 Changes in 2.03:
 	* Actually support comment lines in the configuration file.
 	* PXELINUX: Try to resolve some problems with stack switches.
diff --git a/cpuinit.inc b/cpuinit.inc
index b63ae64d..f64623ed 100644
--- a/cpuinit.inc
+++ b/cpuinit.inc
@@ -27,8 +27,12 @@ check_escapes:
 ;
 ; Now check that there is sufficient low (DOS) memory
 ;
+; NOTE: Linux doesn't use all of real_mode_seg, but we use the same
+; segment for COMBOOT images, which can use all 64K
+;
+dosram_k	equ (real_mode_seg+0x1000) >> 6	; Minimum DOS memory (K)
 		int 12h
-		cmp ax,(real_mode_seg+0xa00) >> 6
+		cmp ax,dosram_k
 		jae enough_ram
 		mov si,err_noram
 		call writestr
diff --git a/isolinux.asm b/isolinux.asm
index b4e8bac1..22f78576 100644
--- a/isolinux.asm
+++ b/isolinux.asm
@@ -73,10 +73,10 @@ vk_end:		equ $			; Should be <= vk_size
 ; Segment assignments in the bottom 640K
 ; 0000h - main code/data segment (and BIOS segment)
 ;
-real_mode_seg	equ 5000h
-vk_seg          equ 4000h		; Virtual kernels
-xfer_buf_seg	equ 3000h		; Bounce buffer for I/O to high mem
-comboot_seg	equ 2000h		; COMBOOT image loading zone
+real_mode_seg	equ 3000h
+vk_seg          equ 2000h		; Virtual kernels
+xfer_buf_seg	equ 1000h		; Bounce buffer for I/O to high mem
+comboot_seg	equ real_mode_seg	; COMBOOT image loading zone
 
 ;
 ; File structure.  This holds the information for each currently open file.
@@ -1502,13 +1502,15 @@ boot_prompt	db 'boot: ', 0
 wipe_char	db BS, ' ', BS, 0
 err_notfound	db 'Could not find kernel image: ',0
 err_notkernel	db CR, LF, 'Invalid or corrupt kernel image.', CR, LF, 0
-err_noram	db 'It appears your computer has less than 360K of low ("DOS")'
-		db 0Dh, 0Ah
+err_noram	db 'It appears your computer has less than '
+		asciidec dosram_k
+		db 'K of low ("DOS")'
+		db CR, LF
 		db 'RAM.  Linux needs at least this amount to boot.  If you get'
-		db 0Dh, 0Ah
+		db CR, LF
 		db 'this message in error, hold down the Ctrl key while'
-		db 0Dh, 0Ah
-		db 'booting, and I will take your word for it.', 0Dh, 0Ah, 0
+		db CR, LF
+		db 'booting, and I will take your word for it.', CR, LF, 0
 err_badcfg      db 'Unknown keyword in config file.', CR, LF, 0
 err_noparm      db 'Missing parameter in config file.', CR, LF, 0
 err_noinitrd    db CR, LF, 'Could not find ramdisk image: ', 0
diff --git a/ldlinux.asm b/ldlinux.asm
index cb146b94..d6c2b05e 100644
--- a/ldlinux.asm
+++ b/ldlinux.asm
@@ -81,11 +81,11 @@ vk_end:		equ $			; Should be <= vk_size
 ;
 ; 0000h - main code/data segment (and BIOS segment)
 ;
-real_mode_seg	equ 7000h
-fat_seg		equ 5000h		; 128K area for FAT (2x64K)
-vk_seg          equ 4000h		; Virtual kernels
-xfer_buf_seg	equ 3000h		; Bounce buffer for I/O to high mem
-comboot_seg	equ 2000h		; COMBOOT image loading zone
+real_mode_seg	equ 5000h
+fat_seg		equ 3000h		; 128K area for FAT (2x64K)
+vk_seg          equ 2000h		; Virtual kernels
+xfer_buf_seg	equ 1000h		; Bounce buffer for I/O to high mem
+comboot_seg	equ real_mode_seg	; COMBOOT image loading zone
 
 ; ---------------------------------------------------------------------------
 ;   BEGIN CODE
@@ -1360,7 +1360,9 @@ boot_prompt	db 'boot: ', 0
 wipe_char	db BS, ' ', BS, 0
 err_notfound	db 'Could not find kernel image: ',0
 err_notkernel	db CR, LF, 'Invalid or corrupt kernel image.', CR, LF, 0
-err_noram	db 'It appears your computer has less than 488K of low ("DOS")'
+err_noram	db 'It appears your computer has less than '
+		asciidec dosram_k
+		db 'K of low ("DOS")'
 		db CR, LF
 		db 'RAM.  Linux needs at least this amount to boot.  If you get'
 		db CR, LF
diff --git a/macros.inc b/macros.inc
index f12ff3fe..3702d4c7 100644
--- a/macros.inc
+++ b/macros.inc
@@ -1,7 +1,7 @@
 ;; $Id$
 ;; -----------------------------------------------------------------------
 ;;   
-;;   Copyright 1994-2002 H. Peter Anvin - All Rights Reserved
+;;   Copyright 1994-2003 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
@@ -39,21 +39,55 @@
 
 ;
 ; Macros similar to res[bwd], but which works in the code segment (after
-; section .text)
+; section .text) or the data segment (section .data)
 ;
-%macro	zb	1
+%macro	zb	1.nolist
 	times %1 db 0
 %endmacro
 
-%macro	zw	1
+%macro	zw	1.nolist
 	times %1 dw 0
 %endmacro
 
-%macro	zd	1
+%macro	zd	1.nolist
 	times %1 dd 0
 %endmacro
 
 ;
+; Macro to emit an unsigned decimal number as a string
+;
+%macro asciidec	1.nolist
+%if %1 >= 1000000000
+	db ((%1/1000000000) % 10) + '0'
+%endif
+%if %1 >= 100000000
+	db ((%1/100000000) % 10) + '0'
+%endif
+%if %1 >= 10000000
+	db ((%1/10000000) % 10) + '0'
+%endif
+%if %1 >= 1000000
+	db ((%1/1000000) % 10) + '0'
+%endif
+%if %1 >= 100000
+	db ((%1/100000) % 10) + '0'
+%endif
+%if %1 >= 10000
+	db ((%1/10000) % 10) + '0'
+%endif
+%if %1 >= 1000
+	db ((%1/1000) % 10) + '0'
+%endif
+%if %1 >= 100
+	db ((%1/100) % 10) + '0'
+%endif
+%if %1 >= 10
+	db ((%1/10) % 10) + '0'
+%endif
+	db (%1 % 10) + '0'
+%endmacro
+
+;
 ; Macros for network byte order of constants
 ;
 %define htons(x)  ( ( ((x) & 0FFh) << 8 ) + ( ((x) & 0FF00h) >> 8 ) )
diff --git a/pxelinux.asm b/pxelinux.asm
index f95fd042..a3064738 100644
--- a/pxelinux.asm
+++ b/pxelinux.asm
@@ -35,7 +35,7 @@ FILENAME_MAX	equ (1 << FILENAME_MAX_LG2)
 NULLFILE	equ 0			; Zero byte == null file name
 REBOOT_TIME	equ 5*60		; If failure, time until full reset
 %assign HIGHMEM_SLOP 128*1024		; Avoid this much memory near the top
-MAX_SOCKETS_LG2	equ 6			; log2(Max number of open sockets)
+MAX_SOCKETS_LG2	equ 5			; log2(Max number of open sockets)
 MAX_SOCKETS	equ (1 << MAX_SOCKETS_LG2)
 TFTP_PORT	equ htons(69)		; Default TFTP port 
 PKT_RETRY	equ 6			; Packet transmit retry count
@@ -89,10 +89,11 @@ vk_end:		equ $			; Should be <= vk_size
 ; Segment assignments in the bottom 640K
 ; 0000h - main code/data segment (and BIOS segment)
 ;
-real_mode_seg	equ 5000h
-vk_seg          equ 4000h		; Virtual kernels
-xfer_buf_seg	equ 3000h		; Bounce buffer for I/O to high mem
-comboot_seg	equ 2000h		; COMBOOT image loading zone
+real_mode_seg	equ 4000h
+vk_seg          equ 3000h		; Virtual kernels
+xfer_buf_seg	equ 2000h		; Bounce buffer for I/O to high mem
+tftp_buf_seg	equ 1000h		; Packet buffers segments
+comboot_seg	equ real_mode_seg	; COMBOOT image loading zone
 
 ;
 ; BOOTP/DHCP packet pattern
@@ -129,6 +130,10 @@ tftp_remoteport	resw 1			; Remote port number
 tftp_remoteip	resd 1			; Remote IP address
 tftp_filepos	resd 1			; Position within file
 tftp_filesize	resd 1			; Total file size
+tftp_pktbuf	resw 1			; Packet buffer offset
+tftp_dataptr	resw 1			; Pointer to available data
+tftp_bytesleft	resw 1			; Unclaimed data bytes
+		resw 5			; Currently unusued
 		endstruc
 
 %ifndef DEPEND
@@ -2069,13 +2074,15 @@ boot_prompt	db 'boot: ', 0
 wipe_char	db BS, ' ', BS, 0
 err_notfound	db 'Could not find kernel image: ',0
 err_notkernel	db CR, LF, 'Invalid or corrupt kernel image.', CR, LF, 0
-err_noram	db 'It appears your computer has less than 384K of low ("DOS")'
-		db 0Dh, 0Ah
+err_noram	db 'It appears your computer has less than '
+		asciidec dosram_k
+		db 'K of low ("DOS")'
+		db CR, LF
 		db 'RAM.  Linux needs at least this amount to boot.  If you get'
-		db 0Dh, 0Ah
+		db CR, LF
 		db 'this message in error, hold down the Ctrl key while'
-		db 0Dh, 0Ah
-		db 'booting, and I will take your word for it.', 0Dh, 0Ah, 0
+		db CR, LF
+		db 'booting, and I will take your word for it.', CR, LF, 0
 err_badcfg      db 'Unknown keyword in config file.', CR, LF, 0
 err_noparm      db 'Missing parameter in config file.', CR, LF, 0
 err_noinitrd    db CR, LF, 'Could not find ramdisk image: ', 0