Move all 16-bit code into one assembly file so we don't have to rely

on ld working properly

7 files changed, 138 insertions, 208 deletions

diff --git a/memdisk/Makefile b/memdisk/Makefile
index e0da72e1..bfa0ce67 100644
--- a/memdisk/Makefile
+++ b/memdisk/Makefile
@@ -20,12 +20,13 @@ M32     := $(call gcc_ok,-m32,)
 ALIGN   := $(call gcc_ok,-falign-functions=0 -falign-jumps=0 -falign-loops=0,-malign-functions=0 -malign-jumps=0 -malign-loops=0)
 
 CC       = gcc $(M32)
-CFLAGS   = -g -W -Wall -Os -fomit-frame-pointer -march=i386 $(ALIGN) \
+CFLAGS   = -g -W -Wall -Wno-sign-compare \
+	   -Os -fomit-frame-pointer -march=i386 $(ALIGN) \
 	   -DVERSION='"$(VERSION)"' -DDATE='"$(DATE)"'
 LDFLAGS  = -g
 INCLUDE  = -I../com32/include
 LD	 = ld -m elf_i386
-NASM     = nasm -O99
+NASM     = nasm -O99 -dVERSION='"$(VERSION)"' -dDATE='"$(DATE)"'
 NINCLUDE = 
 OBJCOPY  = objcopy
 PERL     = perl
diff --git a/memdisk/e820test.c b/memdisk/e820test.c
index cadd2a7f..a0eb4008 100644
--- a/memdisk/e820test.c
+++ b/memdisk/e820test.c
@@ -44,7 +44,7 @@ void printranges(void) {
   }
 }
 
-int main(int argc, char *argv[])
+int main(void)
 {
   uint64_t start, len;
   uint32_t type;
diff --git a/memdisk/init.S16 b/memdisk/init.S16
deleted file mode 100644
index 0a4a330e..00000000
--- a/memdisk/init.S16
+++ /dev/null
@@ -1,189 +0,0 @@
-/* $Id$ */
-/* ----------------------------------------------------------------------- *
- *   
- *   Copyright 2001 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., 53 Temple Place Ste 330,
- *   Bostom MA 02111-1307, USA; either version 2 of the License, or
- *   (at your option) any later version; incorporated herein by reference.
- *
- * ----------------------------------------------------------------------- */
-
-/*
- * init.S
- *
- * memdisk initialization code
- *
- * This module *MUST* get linked first into the image
- */
-
-#include "version.h"
-
-		.text
-		.code16
-
-/*
- * The header derives directly from the Linux kernel and must be first
- * in the binary, hence section .init
- */
-		.org 497
-setup_sects:	.byte 0			# Filled in later
-root_flags:	.word 0
-syssize:	.word 0
-swap_dev:	.word 0
-ram_size:	.word 0
-vid_mode:	.word 0
-root_dev:	.word 0
-boot_flag:	.word 0xAA55
-
-		.globl _start
-_start:
-		jmp	start
-
- # This is the setup header, and it must start at %cs:2 (old 0x9020:2)
-	
-		.ascii	"HdrS"		# header signature
-		.word	0x0203		# header version number (>= 0x0105)
-					# or else old loadlin-1.5 will fail)
-realmode_swtch:	.word	0, 0		# default_switch, SETUPSEG
-start_sys_seg:	.word	0x1000		# obsolete
-version_ptr:	.word	memdisk_version-0x200
-					# pointing to kernel version string
-
-type_of_loader:	.byte	0		# = 0, old one (LILO, Loadlin,
-					#      Bootlin, SYSLX, bootsect...)
-					# See Documentation/i386/boot.txt for
-					# assigned ids
-	
- # flags, unused bits must be zero (RFU) bit within loadflags
-loadflags:
-LOADED_HIGH	= 1			# If set, the kernel is loaded high
-CAN_USE_HEAP	= 0x80			# If set, the loader also has set
-					# heap_end_ptr to tell how much
-					# space behind setup.S can be used for
-					# heap purposes.
-					# Only the loader knows what is free
-
-		.byte	LOADED_HIGH	# Dont force the loader to move 
-					# us to 0x90000
-
-setup_move_size: .word  0		# Unused
-
-code32_start:				# here loaders can put a different
-					# start address for 32-bit code.
-		.long	0x100000	# 0x100000 = default for big kernel
-
-ramdisk_image:	.long	0		# address of loaded ramdisk image
-					# Here the loader puts the 32-bit
-					# address where it loaded the image.
-					# This only will be read by the kernel.
-
-ramdisk_size:	.long	0		# its size in bytes
-
-bootsect_kludge:
-		.word  0, 0
-
-heap_end_ptr:	.word  0		# (Header version 0x0201 or later)
-					# space from here (exclusive) down to
-					# end of setup code can be used by setup
-					# for local heap purposes.
-
-pad1:		.word 0
-cmd_line_ptr:	.long 0			# (Header version 0x0202 or later)
-					# If nonzero, a 32-bit pointer
-					# to the kernel command line.
-					# The command line should be
-					# located between the start of
-					# setup and the end of low
-					# memory (0xa0000), or it may
-					# get overwritten before it
-					# gets read.  If this field is
-					# used, there is no longer
-					# anything magical about the
-					# 0x90000 segment; the setup
-					# can be located anywhere in
-					# low memory 0x10000 or higher.
-
-ramdisk_max:	.long 0xffffffff	# Load ramdisk as high as
-					# absolutely possible
-
-/* ------------------- End of setup header --------------------------- */
-
-LOWSEG = 0x0800		# 0x8000 physical
-
-/*
- * Move ourselves down in memory to reduce the risk of conflicts;
- * the canonicalize CS to match the other segments...
- *
- * The C code uses 32-bit registers to make sure the high part of
- * %esp is zero.
- *
- * The C code expects %cs == %ds == %es == %ss, and %fs == 0.
- */
-start:
-		movw $LOWSEG,%ax
-		movw %ax,%es
-		movzbw setup_sects,%cx
-		inc %cx			# Add one for the boot sector
-		shlw $7,%cx		# Convert to dwords
-		xorw %si,%si
-		xorw %di,%di
-		movw %si,%fs		# %fs -> zero segment
-		cld
-		rep ; movsl %ds:(%si),%es:(%di)
-		movw %ax,%ds
-		movw %ax,%ss
-		xorl %esp,%esp		# Stack at the top of the segment
-		ljmp $LOWSEG, $startc
-
-startc:
-/*
- * Copy the command line, if there is one
- */
-		xorw %di,%di		# Bottom of our own segment
-		movl cmd_line_ptr, %eax
-		andl %eax,%eax
-		jz endcmd		# No command line?
-		movw %ax,%si
-		shrl $4,%eax		# Convert to a segment address
-		andw $0x000F,%si	# Starting offset
-		movw %ax,%gs
-		movw $496,%cx		# Maximum number of bytes
-copycmd:
-		lodsb %gs:(%si),%al
-		andb %al,%al		# Make sure we're null-terminated
-		jz endcmd
-		stosb %al,%es:(%di)
-		loopw copycmd
-endcmd:
-		xorb %al,%al
-		stosb %al,%es:(%di)
-/*
- * Jump to 32-bit code
- */
-		sti
-		call init32		# Call the 32-bit code
-		# The setup function returns the drive number,
-		# which should be returned in %dl
-		movw %ax,%dx
-
-		# If the 32-bit code returns, we are good to go, and the
-		# new boot sector is already loaded
-		cli
-		movw $0x7c00,%sp
-		xorw %si,%si		# Not a partition BS - SI <- 0
-		movw %si,%ds
-		movw %si,%es
-		movw %si,%fs
-		movw %si,%gs
-		movw %si,%ss
-		ljmp $0,$0x7c00		# Entrypoint at 0000:7C00
-
-		.section ".rodata","a"
-memdisk_version:
-		.ascii "MEMDISK " VERSION " " DATE
-		.ascii "Copyright " FIRSTYEAR "-" COPYYEAR " H. Peter Anvin"
-		.byte 0
-
diff --git a/memdisk/memdisk.h b/memdisk/memdisk.h
index 5377120b..b6e36f13 100644
--- a/memdisk/memdisk.h
+++ b/memdisk/memdisk.h
@@ -36,6 +36,7 @@ extern void __attribute__((noreturn)) die(void);
 /* Standard routines */
 #define memcpy(a,b,c) __builtin_memcpy(a,b,c)
 #define memset(a,b,c) __builtin_memset(a,b,c)
+#define strcpy(a,b)   __builtin_strcpy(a,b)
 #define strlen(a)     __builtin_strlen(a)
 
 /* memcpy() but returns a pointer to end of buffer */
diff --git a/memdisk/init32.asm b/memdisk/memdisk16.asm
index bfbca85d..52536ae5 100644
--- a/memdisk/init32.asm
+++ b/memdisk/memdisk16.asm
@@ -2,7 +2,7 @@
 ;; $Id$
 ;; -----------------------------------------------------------------------
 ;;   
-;;   Copyright 1994-2003 H. Peter Anvin - All Rights Reserved
+;;   Copyright 1994-2004 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
@@ -13,17 +13,18 @@
 ;; -----------------------------------------------------------------------
 
 ;;
-;; init32.asm
-;; 
-;; Routine to trampoline into 32-bit protected memory.  This code is
-;; derived from bcopy32.inc and com32.inc in the main SYSLINUX distribution.
+;; init16.asm
+;;
+;; Routine to initialize and to trampoline into 32-bit
+;; protected memory.  This code is derived from bcopy32.inc and
+;; com32.inc in the main SYSLINUX distribution.
 ;;
 
-%define MY_CS 0x0800
-%define CS_BASE (MY_CS << 4)
+MY_CS		equ 0x0800		; Segment address to use
+CS_BASE		equ (MY_CS << 4)	; Corresponding address
 
 ; Low memory bounce buffer
-%define BOUNCE_SEG	(MY_CS+0x1000)
+BOUNCE_SEG	equ (MY_CS+0x1000)
 
 %define DO_WBINVD 0
 
@@ -33,8 +34,121 @@
 		section .data   align=16
 		section .bss    align=16
 
-		global init32
-		
+;; -----------------------------------------------------------------------
+;;  Kernel image header
+;; -----------------------------------------------------------------------
+
+		section .text		; Must be first in image
+		bits 16
+
+		times 497 db 0		; Start of header
+setup_sects	db 0
+root_flags	dw 0
+syssize		dw 0
+swap_dev	dw 0
+ram_size	dw 0
+vid_mode	dw 0
+root_dev	dw 0
+boot_flag	dw 0xAA55
+
+_start:		jmp short start
+
+		db "HdrS"		; Header signature
+		dw 0x0203		; Header version number
+
+realmode_swtch	dw 0, 0			; default_switch, SETUPSEG
+start_sys_seg	dw 0x1000		; obsolete
+version_ptr	dw memdisk_version-0x200	; version string ptr
+type_of_loader	db 0			; Filled in by boot loader
+loadflags	db 1			; Please load high
+setup_move_size	dw 0			; Unused
+code32_start	dd 0x100000		; 32-bit start address
+ramdisk_image	dd 0			; Loaded ramdisk image address
+ramdisk_size	dd 0			; Size of loaded ramdisk
+bootsect_kludge	dw 0, 0
+heap_end_ptr	dw 0
+pad1		dw 0
+cmd_line_ptr	dd 0			; Command line
+ramdisk_max	dd 0xffffffff		; Highest allowed ramdisk address
+
+		section .rodata
+memdisk_version:
+		db "MEMDISK ", VERSION, " ", DATE, 0
+
+;; -----------------------------------------------------------------------
+;;  End kernel image header
+;; -----------------------------------------------------------------------
+
+;
+; Move ourselves down into memory to reduce the risk of conflicts;
+; then canonicalize CS to match the other segments.
+;
+		section .text
+		bits 16
+start:
+		mov ax,MY_CS
+		mov es,ax
+		movzx cx,byte [setup_sects]
+		inc cx			; Add one for the boot sector
+		shl cx,7		; Convert to dwords
+		xor si,si
+		xor di,di
+		mov fs,si		; fs <- 0
+		cld
+		rep movsd
+		mov ds,ax
+		mov ss,ax
+		xor esp,esp		; Stack at top of 64K segment
+		jmp MY_CS:.next
+.next:
+
+;
+; Copy the command line, if there is one
+;
+copy_cmdline:
+		xor di,di		; Bottom of our own segment (= "boot sector")
+		mov eax,[cmd_line_ptr]
+		and eax,eax
+		jz .endcmd		; No command line
+		mov si,ax
+		shr eax,4		; Convert to segment
+		and si,0x000F		; Starting offset only
+		mov gs,ax
+		mov cx,496		; Max number of bytes
+.copycmd:
+		lodsb
+		and al,al
+		jz .endcmd
+		stosb
+		loop .copycmd
+.endcmd:
+		xor al,al
+		stosb
+
+;
+; Now jump to 32-bit code
+;
+		sti
+		call init32
+;
+; When init32 returns, we have been set up, the new boot sector loaded,
+; and we should go and and run the newly loaded boot sector
+;
+; The setup function returns (in AL) the drive number which should be
+; put into DL
+;
+		mov dx,ax
+
+		cli
+		xor esi,esi		; No partition table involved
+		mov ds,si		; Make all the segments consistent
+		mov es,si
+		mov fs,si
+		mov gs,si
+		mov ss,si
+		mov esp,0x7C00		; Good place for SP to start out
+		jmp 0:0x7C00
+
 ;
 ; We enter protected mode, set up a flat 32-bit environment, run rep movsd
 ; and then exit.  IMPORTANT: This code assumes cs == MY_CS.
@@ -51,7 +165,7 @@
 	dd (%1 & 0xff000000) | (%2 & 0xf0000) | ((%3 & 0xf0ff) << 8) | ((%1 & 0x00ff0000) >> 16)
 %endmacro
 	
-		align 4
+		align 8, db 0
 call32_gdt:	dw call32_gdt_size-1	; Null descriptor - contains GDT
 .adj1:		dd call32_gdt+CS_BASE	; pointer for LGDT instruction
 		dw 0
@@ -75,7 +189,6 @@ call32_gdt_size:	equ $-call32_gdt
 
 err_a20:	db 'ERROR: A20 gate not responding!',13,10,0
 	
-		bits 16
 		section .bss
 		alignb 4
 SavedSSSP	resd 1			; Place to save SS:SP
@@ -91,6 +204,7 @@ Target_Seg	dw 20h			; Target CS
 A20Type		dw 0			; Default = unknown
 		
 		section .text
+		bits 16
 ;
 ; Routines to enable and disable (yuck) A20.  These routines are gathered
 ; from tips from a couple of sources, including the Linux kernel and
@@ -110,7 +224,7 @@ A20Type		dw 0			; Default = unknown
 %define A20_KBC		3		; A20 through KBC
 %define A20_FAST	4		; A20 through port 92h
 
-		align 2
+		align 2, db 0
 A20List		dw a20_dunno, a20_none, a20_bios, a20_kbc, a20_fast
 A20DList	dw a20d_dunno, a20d_none, a20d_bios, a20d_kbc, a20d_fast
 a20_adjust_cnt	equ ($-A20List)/2
@@ -360,7 +474,7 @@ try_wbinvd:
 		alignb 4
 PMESP		resd 1			; Protected mode %esp
 
-		section .idt nobits alloc exec write align=4096
+		section .idt nobits align=4096
 		alignb 4096
 pm_idt		resb 4096		; Protected-mode IDT, followed by interrupt stubs
 
diff --git a/memdisk/setup.c b/memdisk/setup.c
index b3bcc9dd..d52e11cd 100644
--- a/memdisk/setup.c
+++ b/memdisk/setup.c
@@ -17,7 +17,6 @@
 #include "version.h"
 #include "memdisk.h"
 
-/* A pointer to this is stored in the header */
 const char memdisk_version[] =
 "MEMDISK " VERSION " " DATE;
 const char copyright[] = 
@@ -369,6 +368,8 @@ struct dosemu_header {
   uint8_t pad[105];
 } __attribute__((packed));
 
+#define FOUR(a,b,c,d) (((a) << 24)|((b) << 16)|((c) << 8)|(d))
+
 const struct geometry *get_disk_image_geometry(uint32_t where, uint32_t size)
 {
   static struct geometry hd_geometry = { 0, 0, 0, 0, 0, 0, 0x80 };
@@ -400,7 +401,8 @@ const struct geometry *get_disk_image_geometry(uint32_t where, uint32_t size)
 
   /* Do we have a DOSEMU header? */
   memcpy(&dosemu, (char *)where+hd_geometry.offset, sizeof dosemu);
-  if ( !__builtin_memcmp("DOSEMU", dosemu.magic, 7) ) {
+  if ( ((unsigned long *)dosemu.magic)[0] == FOUR('D','O','S','E') &&
+       (((unsigned long *)dosemu.magic)[1] & 0xffffff) == FOUR('M','U',0,0) ) {
     /* Always a hard disk unless overruled by command-line options */
     hd_geometry.driveno = 0x80;
     hd_geometry.type = 0;
diff --git a/memdisk/unzip.c b/memdisk/unzip.c
index b7d2fdd9..18cf6e07 100644
--- a/memdisk/unzip.c
+++ b/memdisk/unzip.c
@@ -122,6 +122,7 @@ static void *malloc(int size)
 static void free(void *where)
 {
   /* Don't care */
+  (void)where;
 }
 
 static void gzip_mark(void **ptr)