--- trunk/mkinitrd-magellan/isolinux/layout.inc	2007/09/01 22:45:15	532
+++ trunk/mkinitrd-magellan/isolinux/layout.inc	2010/08/19 09:50:43	1133
@@ -1,7 +1,7 @@
-; $Id: layout.inc,v 1.1 2007-09-01 22:44:05 niro Exp $
 ; -----------------------------------------------------------------------
-;   
-;   Copyright 1994-2004 H. Peter Anvin - All Rights Reserved
+;
+;   Copyright 1994-2009 H. Peter Anvin - All Rights Reserved
+;   Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
 ;
 ;   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
@@ -17,6 +17,8 @@
 ; Memory layout of segments
 ;
 
+		; Default to 16-bit code
+		bits 16
 
 ; Memory below 0800h is reserved for the BIOS and the MBR.
 BSS_START	equ 0800h
@@ -24,41 +26,119 @@
 ; Text starts at the load address of 07C00h.
 TEXT_START	equ 7C00h
 
+;
+; Stack layout
+;
+; PXELINUX: There are apparently some AMI BIOSes in the field which
+; put their BEV stack somewhere below 7C00h (and therefore don't
+; handle localboot properly), so avoid that immediate memory region.
+; The range that is known to be bad is approximately 75E8..7C00; the
+; lower bound is tight.
+; 
+		global STACK_LEN, STACK_TOP, STACK_BASE
+STACK_LEN	equ 4096
+%if IS_PXELINUX
+STACK_TOP	equ 7000h
+%else
+STACK_TOP	equ 7c00h
+%endif
+STACK_BASE	equ STACK_TOP - STACK_LEN
+
 ; The secondary BSS section, above the text; we really wish we could
 ; just make it follow .bcopy32 or hang off the end,
 ; but it doesn't seem to work that way.
-LATEBSS_START	equ 0B000h
-
-; Reserve memory for the stack.  This causes checkov to abort the
-; compile if we violate this space.
-STACK_SIZE	equ 4096
-STACK_START	equ TEXT_START-STACK_SIZE
+LATEBSS_START	equ 0B800h
 
-%ifdef MAP
-		[map all MAP]
+;
+; The various sections and their relationship
+;
+		; Use .earlybss for things that MUST be in low memory.
+		section .earlybss	nobits
+		section .config		write progbits align=4
+		section .replacestub	exec write progbits align=16
+
+		; Use .bss for things that doesn't have to be in low memory;
+		; with .bss1 and .bss2 to offload.  .earlybss should be used
+		; for things that absolutely have to be below 0x7c00.
+		section .bss		write nobits align=16
+
+%if 0 ; IS_PXELINUX
+		; Warning here: RBFG build 22 randomly overwrites
+		; memory location [0x5680,0x576c), possibly more.  It
+		; seems that it gets confused and screws up the
+		; pointer to its own internal packet buffer and starts
+		; writing a received ARP packet into low memory.
+		section .rbfg		write nobits
+RBFG_brainfuck:	resb 2048		; Bigger than an Ethernet packet...
 %endif
 
+		section .bss2		write nobits align=16
+
+		section .text		exec write progbits align=16
+		section .bcopyxx	exec write progbits align=16
+		section .data		write progbits align=16
+
+		section .adv		write nobits align=512
+
+		; .uibss contains bss data which is guaranteed to be
+		; safe to clobber during the loading of the image.  This
+		; is because while loading the primary image we will clobber
+		; the spillover from the last fractional sector load.
+		section .uibss		write nobits align=16
+
+		; Normal bss...
+		section .bss1		write nobits align=16
+
+		; Symbols from linker script
+%macro SECINFO 1
+		extern __%1_start, __%1_lma, __%1_end
+		extern __%1_len, __%1_dwords
+%endmacro
+		SECINFO config
+		SECINFO replacestub
+
+		global _start
+
+		section .text
+
 ;
-; The various sections and their relationship
+; Segment assignments in the bottom 640K
+; Keep the low-memory footprint as small as possible... overrun is a hard
+; failure!
+;
+; 0000h - main code/data segment (and BIOS segment)
+
+xfer_buf_seg	equ 1000h
+aux_seg		equ 2000h
+
+serial_buf_size	equ 4096		; Should be a power of 2
+
+;
+; Contents of aux_seg
 ;
-		org TEXT_START
+		struc aux
+.fontbuf	resb 8192
+.serial		resb serial_buf_size
 
-		; NASM BUG: refers to hacks to handle NASM 0.98.38 bugs; might need
-		; conditional compilation
-	
-		section .earlybss nobits start=BSS_START
-		section .bcopy32  align=4 valign=16 follows=.data vfollows=.earlybss
-		; NASM BUG: follows= here should be vfollows=
-		section .bss      nobits align=256 follows=.bcopy32
-
-		section .text	  start=TEXT_START
-		; NASM BUG: follows=.text not accepted here
-		section .data	  align=16 ; follows=.text
-
-		; NASM BUG: We would like to do follows=.bcopy32
-		section .latebss  nobits align=16 start=LATEBSS_START
-
-		; Reserve space for stack
-		section .stack	  nobits align=16 start=STACK_START
-Stack		resb	STACK_SIZE
+		alignb 4096		; Align the next segment to 4K
+		endstruc
+
+aux_seg_end	equ aux_seg + (aux_size >> 4)
+
+;
+; Bounce buffer for I/O to high mem
+; Note: we keep all the segments page-aligned, even if that probably
+; is somewhat excessive.  Sector alignment is obligatory, however.
+;
+
+%if IS_ISOLINUX
+; ISOLINUX doesn't have a block cache yet
+real_mode_seg	equ aux_seg_end
+%else
+cache_seg	equ aux_seg_end		; 64K area for metadata cache
+real_mode_seg	equ cache_seg + 1000h
+
+pktbuf_seg	equ cache_seg		; PXELINUX packet buffers
+%endif
 
+comboot_seg	equ real_mode_seg	; COMBOOT image loading zone