Reorganize memory so we don't have to relocate pxelinux and have more

stack for extlinux; add tool to check for section overflow.

12 files changed, 125 insertions, 22 deletions

diff --git a/Makefile b/Makefile
index 13569d1b..742ea126 100644
--- a/Makefile
+++ b/Makefile
@@ -125,15 +125,18 @@ kwdhash.gen: keywords genhash.pl
 ldlinux.bin: ldlinux.asm kwdhash.gen version.gen
 	$(NASM) -f bin -DDATE_STR="'$(DATE)'" -DHEXDATE="$(HEXDATE)" \
 		-DMAP=ldlinux.map -l ldlinux.lst -o ldlinux.bin ldlinux.asm
+	$(PERL) checkov.pl ldlinux.map $@
 
 pxelinux.bin: pxelinux.asm kwdhash.gen version.gen
 	$(NASM) -f bin -DDATE_STR="'$(DATE)'" -DHEXDATE="$(HEXDATE)" \
 		-DMAP=pxelinux.map -l pxelinux.lst -o pxelinux.bin pxelinux.asm
+	$(PERL) checkov.pl pxelinux.map $@
 
 isolinux.bin: isolinux.asm kwdhash.gen version.gen checksumiso.pl
 	$(NASM) -f bin -DDATE_STR="'$(DATE)'" -DHEXDATE="$(HEXDATE)" \
 		-DMAP=isolinux.map -l isolinux.lst -o isolinux.bin isolinux.asm
-	$(PERL) checksumiso.pl isolinux.bin
+	$(PERL) checkov.pl isolinux.map $@
+	$(PERL) checksumiso.pl $@
 
 # Special verbose version of isolinux.bin
 isolinux-debug.bin: isolinux.asm kwdhash.gen version.gen checksumiso.pl
@@ -141,11 +144,13 @@ isolinux-debug.bin: isolinux.asm kwdhash.gen version.gen checksumiso.pl
 		-DDEBUG_MESSAGES \
 		-DMAP=isolinux-debug.map -l isolinux-debug.lst \
 		-o isolinux-debug.bin isolinux.asm
+	$(PERL) checkov.pl isolinux-debug.map $@
 	$(PERL) checksumiso.pl $@
 
 extlinux.bin: extlinux.asm kwdhash.gen version.gen
 	$(NASM) -f bin -DDATE_STR="'$(DATE)'" -DHEXDATE="$(HEXDATE)" \
 		-DMAP=extlinux.map -l extlinux.lst -o extlinux.bin extlinux.asm
+	$(PERL) checkov.pl extlinux.map $@
 
 pxelinux.0: pxelinux.bin
 	cp pxelinux.bin pxelinux.0
diff --git a/cache.inc b/cache.inc
index c2472abb..05f7d62d 100644
--- a/cache.inc
+++ b/cache.inc
@@ -77,7 +77,7 @@ getcachesector:
 		pop cx
 		ret
 
-		section .bss
+		section .latebss
 		alignb 4
 CachePtrs	resd 65536/SECTOR_SIZE	; Cached sector pointers
 NextCacheSlot	resw 1			; Next cache slot to occupy
diff --git a/checkov.pl b/checkov.pl
new file mode 100644
index 00000000..b9ebf7be
--- /dev/null
+++ b/checkov.pl
@@ -0,0 +1,80 @@
+#!/usr/bin/perl
+#
+# checkov.pl
+#
+# Check NASM map output for overflow
+#
+# This assumes that a section for which start != vstart, both
+# ranges need to be checked for overflow (true for SYSLINUX)
+#
+
+($in, $target) = @ARGV;
+
+sub overlap($$$$) {
+    my($s1,$e1,$s2,$e2) = @_;
+    
+    return 1 if ( $s2 < $e1 && $e2 > $s1 );
+    return 1 if ( $s1 < $e2 && $e1 > $s2 );
+
+    return 0;
+}
+
+open(IN, '<', $in) or die "$0: Cannot open input file: $in\n";
+
+$section = undef;
+while ( $line = <IN> ) {
+    if ( $line =~ /^-/ ) {
+	if ( $line =~ /^\-\-\-\- Section (\S+) / ) {
+	    $section = $1;
+	} else {
+	    $section = undef;
+	}
+    } elsif ( defined($section) ) {
+	if ( $line =~ /^length\:\s*(\S+)/ ) {
+	    $length{$section} = hex $1;
+	} elsif ( $line =~ /^start\:\s*(\S+)/ ) {
+	    $start{$section} = hex $1;
+	} elsif ( $line =~ /^vstart\:\s*(\S+)/ ) {
+	    $vstart{$section} = hex $1;
+	}
+    }
+}
+close(IN);
+
+$err = 0;
+
+foreach $s ( keys(%start) ) {
+    $sstart  = $start{$s};
+    $svstart = $vstart{$s};
+    $send    = $sstart + $length{$s};
+    $svend   = $svstart + $length{$s};
+
+    if ( $send > 0x10000 || $svend > 0x10000 ) {
+	print STDERR "$target: 16-bit overflow on section $s\n";
+	$err++;
+    }
+
+    foreach $o ( keys(%start) ) {
+	next if ( $s ge $o );
+	
+	$ostart  = $start{$o};
+	$ovstart = $vstart{$o};
+	$oend    = $ostart + $length{$o};
+	$ovend   = $ovstart + $length{$o};
+	
+	if ( overlap($sstart, $send, $ostart, $oend) ||
+	     overlap($svstart, $svend, $ostart, $oend) ||
+	     overlap($sstart, $send, $ovstart, $ovend) ||
+	     overlap($svstart, $svend, $ovstart, $ovend) ) {
+	    print STDERR "$target: section $s overlaps section $o\n";
+	    $err++;
+	}
+    }
+}
+
+if ( $err ) {
+    unlink($target);
+    exit(1);
+} else {
+    exit(0);
+}
diff --git a/dnsresolv.inc b/dnsresolv.inc
index 05d0fff3..8a64f400 100644
--- a/dnsresolv.inc
+++ b/dnsresolv.inc
@@ -1,7 +1,7 @@
 ; -*- fundamental -*-
 ; -----------------------------------------------------------------------
 ;   
-;   Copyright 2004 H. Peter Anvin - All Rights Reserved
+;   Copyright 2004-2005 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
@@ -10,6 +10,7 @@
 ;   (at your option) any later version; incorporated herein by reference.
 ;
 ; -----------------------------------------------------------------------
+; $Id$
 
 ;
 ; dnsresolv.inc
@@ -150,8 +151,8 @@ dns_skiplabel:
 .rdata:		equ $
 		endstruc
 
-		section .bss
-		alignb 2, db 0
+		section .latebss
+		alignb 2
 DNSSendBuf	resb DNS_MAX_PACKET
 DNSRecvBuf	resb DNS_MAX_PACKET
 LocalDomain	resb 256		; Max possible length
diff --git a/extlinux.asm b/extlinux.asm
index c7a73810..0e6182b1 100644
--- a/extlinux.asm
+++ b/extlinux.asm
@@ -114,7 +114,7 @@ trackbuf	resb trackbufsize	; Track buffer goes here
 getcbuf		resb trackbufsize
 		; ends at 4800h
 
-		section .bss
+		section .latebss
 SuperBlock	resb 1024		; ext2 superblock
 SuperInfo	resq 16			; DOS superblock expanded
 ClustSize	resd 1			; Bytes/cluster ("block")
@@ -619,8 +619,14 @@ print_bios:
 		jne .cbios
 		mov si,ebios_name
 .cbios:
+		mov [BIOSName],si
 		call writestr
 
+		section .bss
+%define	HAVE_BIOSNAME 1
+BIOSName	resw 1
+
+		section .text
 ;
 ; Now we read the rest of LDLINUX.SYS.	Don't bother loading the first
 ; sector again, though.
@@ -716,8 +722,8 @@ checksumerr_msg	db ' Load error - ', 0	; Boot failed appended
 ;
 ; BIOS type string
 ;
-cbios_name	db 'CBIOS', 0
-ebios_name	db 'EBIOS', 0
+cbios_name	db ' CBIOS', 0
+ebios_name	db ' EBIOS', 0
 
 ;
 ; Debug routine
diff --git a/graphics.inc b/graphics.inc
index 273cc6ba..df3b3a04 100644
--- a/graphics.inc
+++ b/graphics.inc
@@ -319,7 +319,7 @@ vgacursorcommon:
 linear_color	db 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0
 UsingVGA	db 0
 
-		section .bss
+		section .latebss
 		alignb 2
 GraphXSize	resw 1			; Width of splash screen file
 VGAPos		resw 1			; Pointer into VGA memory
diff --git a/layout.inc b/layout.inc
index 46dfc084..6021d69f 100644
--- a/layout.inc
+++ b/layout.inc
@@ -18,15 +18,15 @@
 ;
 
 
-; Memory below 0800h is reserved for the BIOS and the MBR
+; Memory below 0800h is reserved for the BIOS and the MBR.
 BSS_START	equ 0800h
 
-; PXELINUX needs lots of BSS, so it relocates itself on startup
-%if IS_PXELINUX
-TEXT_START	equ 0A000h
-%else
+; Text starts at the load address of 07C00h.
 TEXT_START	equ 7C00h
-%endif
+
+; The secondary BSS section, above the text; we really wish we could
+; just make it follow .bcopy32, but it doesn't seem to work that way.
+LATEBSS_START	equ 0B000h
 
 %ifdef MAP
 		[map all MAP]
@@ -50,6 +50,5 @@ TEXT_START	equ 7C00h
 		section .data	  align=16 ; follows=.text
 
 		; NASM BUG: We would like to do follows=.bcopy32
-		section .latebss  nobits align=16 start=0E000h
-
+		section .latebss  nobits align=16 start=LATEBSS_START
 
diff --git a/ldlinux.asm b/ldlinux.asm
index 1651ae18..a47aeb36 100644
--- a/ldlinux.asm
+++ b/ldlinux.asm
@@ -632,8 +632,14 @@ print_bios:
 		jne .cbios
 		mov si,ebios_name
 .cbios:
+		mov [BIOSName],si
 		call writestr
 
+		section .bss
+%define	HAVE_BIOSNAME 1
+BIOSName	resw 1
+
+		section .text
 ;
 ; Now we read the rest of LDLINUX.SYS.	Don't bother loading the first
 ; sector again, though.
@@ -729,8 +735,8 @@ checksumerr_msg	db ' Load error - ', 0	; Boot failed appended
 ;
 ; BIOS type string
 ;
-cbios_name	db 'CBIOS', 0
-ebios_name	db 'EBIOS', 0
+cbios_name	db ' CBIOS', 0
+ebios_name	db ' EBIOS', 0
 
 ;
 ; Debug routine
diff --git a/parsecmd.inc b/parsecmd.inc
index 65a58ad3..95432e5a 100644
--- a/parsecmd.inc
+++ b/parsecmd.inc
@@ -93,7 +93,7 @@ getcommand:
 		jc .eof
 		jmp short .skipline
 
-		section .bss
+		section .latebss
 		alignb 4
 vk_size		equ (vk_end + 3) & ~3
 VKernelBuf:	resb vk_size		; "Current" vkernel
diff --git a/parseconfig.inc b/parseconfig.inc
index 32e84beb..30fd5443 100644
--- a/parseconfig.inc
+++ b/parseconfig.inc
@@ -359,7 +359,7 @@ SerialPort	dw 0			; Serial port base (or 0 for no serial port)
 VKernelBytes	dw 0			; Number of bytes used by vkernels
 VKernel		db 0			; Have we seen any "label" statements?
 
-		section .bss
+		section .latebss
                 alignb 4		; For the good of REP MOVSD
 command_line	resb max_cmd_len+2	; Command line buffer
 		alignb 4
diff --git a/pxelinux.asm b/pxelinux.asm
index db6061f9..1084a0c6 100644
--- a/pxelinux.asm
+++ b/pxelinux.asm
@@ -207,7 +207,7 @@ PXEStack	resd 1			; Saved stack during PXE call
 ; writing a received ARP packet into low memory.
 RBFG_brainfuck	resb 0E00h
 
-		section .bss
+		section .latebss
 		alignb 4
 RebootTime	resd 1			; Reboot timeout, if set by option
 StrucPtr	resd 1			; Pointer to PXENV+ or !PXE structure
@@ -276,6 +276,7 @@ _start:
 		mov ds,ax
 		mov es,ax	
 
+%if TEXT_START != 0x7c00
 		; This is uglier than it should be, but works around
 		; some NASM 0.98.38 bugs.
 		mov di,section..bcopy32.start
@@ -285,6 +286,7 @@ _start:
 		shr cx,2
 		std			; Overlapping areas, copy backwards
 		rep movsd
+%endif
 
 		jmp 0:_start1		; Canonicalize address
 _start1:
diff --git a/ui.inc b/ui.inc
index 7174dbee..0d7cc408 100644
--- a/ui.inc
+++ b/ui.inc
@@ -166,6 +166,10 @@ print_version:
 		push di				; Command line write pointer
 		mov si,syslinux_banner
 		call cwritestr
+%ifdef HAVE_BIOSNAME
+		mov si,[BIOSName]
+		call cwritestr
+%endif
 		mov si,copyright_str
 		call cwritestr