x86 Boot enhancements, boot params 1/11

diff -uNr linux-2.5.12/Documentation/i386/zero-page.txt linux-2.5.12.boot.boot_params/Documentation/i386/zero-page.txt
@@ -9,7 +9,11 @@
   arch/i386/boot/video.S
   arch/i386/kernel/head.S
   arch/i386/kernel/setup.c
- 
+
+See include/asm-i386/boot_param.h a structure is kept there with
+uptodate information.  The kernel no longer copies this information
+into the empty zero page, but instead uses it directly.
+
 
 Offset	Type		Description
 ------  ----		-----------

@@ -65,7 +69,7 @@
 0x21c	unsigned long	INITRD_SIZE, size in bytes of ramdisk image
 0x220	4 bytes		(setup.S)
 0x224	unsigned short	setup.S heap end pointer
-0x2d0 - 0x600		E820MAP
+0x2d0 - 0x550		E820MAP
 
 0x800	string, 2K max	COMMAND_LINE, the kernel commandline as
 			copied using CL_OFFSET.

diff -uNr linux-2.5.12.boot.boot_params/arch/i386/Makefile linux-2.5.12.boot.vmlinuxlds/arch/i386/Makefile
@@ -18,7 +18,7 @@
 
 LD=$(CROSS_COMPILE)ld -m elf_i386
 OBJCOPY=$(CROSS_COMPILE)objcopy -O binary -R .note -R .comment -S
-LDFLAGS=-e stext
+LDFLAGS=
 LINKFLAGS =-T $(TOPDIR)/arch/i386/vmlinux.lds $(LDFLAGS)
 
 CFLAGS += -pipe

diff -uNr linux-2.5.12.boot.boot_params/arch/i386/kernel/head.S linux-2.5.12.boot.vmlinuxlds/arch/i386/kernel/head.S
@@ -41,7 +41,7 @@
  *
  * On entry, %esi points to the real-mode code as a 32-bit pointer.
  */
-startup_32:
+ENTRY(startup_32)
 /*
  * Set segments to known values
  */

diff -uNr linux-2.5.12.boot.boot_params/arch/i386/vmlinux.lds linux-2.5.12.boot.vmlinuxlds/arch/i386/vmlinux.lds
@@ -3,7 +3,13 @@
  */
 OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
 OUTPUT_ARCH(i386)
-ENTRY(_start)
+physical_startup_32 = startup_32 - 0xC0000000;
+ENTRY(physical_startup_32)
+PHDRS
+{
+	text PT_LOAD AT(0x100000);
+
+}
 SECTIONS
 {
   . = 0xC0000000 + 0x100000;

@@ -12,7 +18,7 @@
 	*(.text)
 	*(.fixup)
 	*(.gnu.warning)
-	} = 0x9090
+	} :text = 0x9090
 
   _etext = .;			/* End of text section */
 

@@ -73,8 +79,16 @@
   __bss_start = .;		/* BSS */
   .bss : {
 	*(.bss)
+        _end = . ;
+	/* Reserve space for the bootmem bitmap,
+	 * With a start at 0xC0000000 this is just 32k in the worst case.
+	 *
+	 * Ideally this would be in an initdata segment but that causes
+	 * problems with memory being reserved twice.
+	 */
+	. = ALIGN(4096);
+	. = . + 32768;
 	}
-  _end = . ;
 
   /* Sections to be discarded */
   /DISCARD/ : {

diff -uNr linux-2.5.12.boot.vmlinuxlds/arch/i386/boot/setup.S linux-2.5.12.boot.spring-cleaning/arch/i386/boot/setup.S
@@ -166,7 +166,12 @@
 # End of setup header #####################################################
 
 start_of_setup:
+#ifndef __BIG_KERNEL__
 # Bootlin depends on this being done early
+#NOTE:  Bootlin was written before the kernel had hooks for anything
+# 	used the BIOS calls setup.S made as hooks (ouch!)
+#       Bootlin only loaded zImages, so we can drop support for it
+#       when we are loading a bzImage.
 	movw	$0x01500, %ax
 	movb	$0x81, %dl
 	int	$0x13

@@ -177,6 +182,7 @@
 	movb	$0x80, %dl
 	int	$0x13
 #endif
+#endif /* __BIG_KERNEL__ */
 
 # Set %ds = %cs, we know that SETUPSEG = %cs at this point
 	movw	%cs, %ax		# aka SETUPSEG

@@ -226,6 +232,7 @@
 
 # We now have to find the rest of the setup code/data
 bad_sig:
+#ifndef __BIG_KERNEL__
 	movw	%cs, %ax			# SETUPSEG
 	subw	$DELTA_INITSEG, %ax		# INITSEG
 	movw	%ax, %ds

@@ -255,7 +262,7 @@
 	jne	no_sig
 
 	jmp	good_sig
-
+#endif /* __BIG_KERNEL__ */
 no_sig:
 	lea	no_sig_mess, %si
 	call	prtstr

@@ -268,10 +275,8 @@
 	movw	%cs, %ax			# aka SETUPSEG
 	subw	$DELTA_INITSEG, %ax 		# aka INITSEG
 	movw	%ax, %ds
+#ifdef __BIG_KERNEL__
 # Check if an old loader tries to load a big-kernel
-	testb	$LOADED_HIGH, %cs:loadflags	# Do we have a big kernel?
-	jz	loader_ok			# No, no danger for old loaders.
-
 	cmpb	$0, %cs:type_of_loader 		# Do we have a loader that
 						# can deal with us?
 	jnz	loader_ok			# Yes, continue.

@@ -284,6 +289,7 @@
 	jmp	no_sig_loop
 
 loader_panic_mess: .string "Wrong loader, giving up..."
+#endif /* __BIG_KERNEL__ */
 
 loader_ok:
 # Get memory size (extended mem, kB)

@@ -561,15 +567,8 @@
 	movl	%cs:code32_start, %eax
 	movl	%eax, %cs:code32
 
-# Now we move the system to its rightful place ... but we check if we have a
-# big-kernel. In that case we *must* not move it ...
-	testb	$LOADED_HIGH, %cs:loadflags
-	jz	do_move0			# .. then we have a normal low
-						# loaded zImage
-						# .. or else we have a high
-						# loaded bzImage
-	jmp	end_move			# ... and we skip moving
-
+#ifndef __BIG_KERNEL__
+# Move the kernel image where it expects to be loaded.
 do_move0:
 	movw	$0x100, %ax			# start of destination segment
 	movw	%cs, %bp			# aka SETUPSEG

@@ -595,6 +594,8 @@
 	jb	do_move
 
 end_move:
+#endif /* !__BIG_KERNEL__ */
+	
 # then we load the segment descriptors
 	movw	%cs, %ax			# aka SETUPSEG
 	movw	%ax, %ds

diff -uNr linux-2.5.12.boot.spring-cleaning/arch/i386/boot/setup.S linux-2.5.12.boot.syntax/arch/i386/boot/setup.S
@@ -59,6 +59,12 @@
 #define SIG1	0xAA55
 #define SIG2	0x5A5A
 
+#ifndef __BIG_KERNEL__
+#define KERNEL_START LOW_BASE		/* zImage */
+#else
+#define KERNEL_START HIGH_BASE 		/* bzImage */
+#endif
+
 INITSEG  = DEF_INITSEG		# 0x9000, we move boot here, out of the way
 SYSSEG   = DEF_SYSSEG		# 0x1000, system loaded at 0x10000 (65536).
 SETUPSEG = DEF_SETUPSEG		# 0x9020, this is the current segment

@@ -118,13 +124,8 @@
 					# loader knows how much data behind
 					# us also needs to be loaded.
 
-code32_start:				# here loaders can put a different
+code32_start:	.long	KERNEL_START	# here loaders can put a different
 					# start address for 32-bit code.
-#ifndef __BIG_KERNEL__
-		.long	0x1000		#   0x1000 = default for zImage
-#else
-		.long	0x100000	# 0x100000 = default for big kernel
-#endif
 
 ramdisk_image:	.long	0		# address of loaded ramdisk image
 					# Here the loader puts the 32-bit

@@ -343,7 +344,7 @@
 
 	incb	(E820NR)
 	movw	%di, %ax
-	addw	$20, %ax
+	addw	$E820ENTRY_SIZE, %ax
 	movw	%ax, %di
 again820:
 	cmpl	$0, %ebx			# check to see if

diff -uNr linux-2.5.12.boot.syntax/arch/i386/boot/setup.S linux-2.5.12.boot.heap/arch/i386/boot/setup.S
@@ -65,6 +65,8 @@
 #define KERNEL_START HIGH_BASE 		/* bzImage */
 #endif
 
+#define DELTA_BOOTSECT 512
+
 INITSEG  = DEF_INITSEG		# 0x9000, we move boot here, out of the way
 SYSSEG   = DEF_SYSSEG		# 0x1000, system loaded at 0x10000 (65536).
 SETUPSEG = DEF_SETUPSEG		# 0x9020, this is the current segment

@@ -73,15 +75,10 @@
 DELTA_INITSEG = SETUPSEG - INITSEG	# 0x0020
 
 .code16
-.globl begtext, begdata, begbss, endtext, enddata, endbss
+.globl _setup, _esetup
 
 .text
-begtext:
-.data
-begdata:
-.bss
-begbss:
-.text
+_setup:	
 
 start:
 	jmp	trampoline

@@ -137,7 +134,7 @@
 bootsect_kludge:
 		.word  bootsect_helper, SETUPSEG
 
-heap_end_ptr:	.word	modelist+1024	# (Header version 0x0201 or later)
+heap_end_ptr:	.word	_esetup_heap	# (Header version 0x0201 or later)
 					# space from here (exclusive) down to
 					# end of setup code can be used by setup
 					# for local heap purposes.

@@ -162,8 +159,12 @@
 					# The highest safe address for
 					# the contents of an initrd
 
+# variables private to setup.S (not for bootloaders)
+real_filesz:				# Datasize of the real mode kernel
+		.long (_esetup - _setup) + DELTA_BOOTSECT
 trampoline:	call	start_of_setup
-		.space	1024
+		# Don't let the E820 map overlap code
+		. = (E820MAP - DELTA_BOOTSECT) + (E820MAX * E820ENTRY_SIZE)
 # End of setup header #####################################################
 
 start_of_setup:

@@ -1042,11 +1043,8 @@
 # After this point, there is some free space which is used by the video mode
 # handling code to store the temporary mode table (not used by the kernel).
 
-modelist:
-
-.text
-endtext:
-.data
-enddata:
-.bss
-endbss:
+_esetup:
+.section ".setup.heap", "a", @nobits
+_setup_heap:
+. = DEF_HEAP_SIZE
+_esetup_heap:

diff -uNr linux-2.5.12.boot.syntax/arch/i386/boot/video.S linux-2.5.12.boot.heap/arch/i386/boot/video.S
@@ -117,6 +117,12 @@
 	xorw	%ax, %ax
 	movw	%ax, %gs	# GS is zero
 	cld
+
+	# Setup the heap
+	movl	real_filesz, %eax
+	subl	$DELTA_BOOTSECT, %eax
+	movw	%ax, heap_start
+	
 	call	basic_detect	# Basic adapter type testing (EGA/VGA/MDA/CGA)
 #ifdef CONFIG_VIDEO_SELECT
 	movw	%fs:(0x01fa), %ax		# User selected video mode

@@ -201,7 +207,7 @@
 #ifdef CONFIG_VIDEO_SELECT
 # Fetching of VESA frame buffer parameters
 mopar_gr:
-	leaw	modelist+1024, %di
+	movw	heap_start, %di
 	movb	$0x23, %fs:(PARAM_HAVE_VGA)
 	movw	16(%di), %ax
 	movw	%ax, %fs:(PARAM_LFB_LINELENGTH)

@@ -223,7 +229,7 @@
 	movl	%eax, %fs:(PARAM_LFB_COLORS+4)
 
 # get video mem size
-	leaw	modelist+1024, %di
+	movw	heap_start, %di
 	movw	$0x4f00, %ax
 	int	$0x10
 	xorl	%eax, %eax

@@ -284,7 +290,7 @@
 	leaw	listhdr, %si			# Table header
 	call	prtstr
 	movb	$0x30, %dl			# DL holds mode number
-	leaw	modelist, %si
+	movw	modelist, %si
 lm1:	cmpw	$ASK_VGA, (%si)			# End?
 	jz	lm2
 

@@ -529,7 +535,7 @@
 	jmp	_m_s
 
 check_vesa:
-	leaw	modelist+1024, %di
+	movw	heap_start, %di
 	subb	$VIDEO_FIRST_VESA>>8, %bh
 	movw	%bx, %cx			# Get mode information structure
 	movw	$0x4f01, %ax

@@ -774,12 +780,13 @@
 	mulb	%ah
 	movw	%ax, %cx			# CX=number of characters
 	addw	%ax, %ax			# Calculate image size
-	addw	$modelist+1024+4, %ax
+	addw	heap_start, %ax
+	addw	$4, %ax
 	cmpw	heap_end_ptr, %ax
 	jnc	sts1				# Unfortunately, out of memory
 
 	movw	%fs:(PARAM_CURSOR_POS), %ax	# Store mode params
-	leaw	modelist+1024, %di
+	movw	heap_start, %di
 	stosw
 	movw	%bx, %ax
 	stosw

@@ -802,7 +809,7 @@
 	call	mode_params			# Get parameters of current mode
 	movb	%fs:(PARAM_VIDEO_LINES), %cl
 	movb	%fs:(PARAM_VIDEO_COLS), %ch
-	leaw	modelist+1024, %si		# Screen buffer
+	movw	heap_start, %si			# Screen buffer
 	lodsw					# Set cursor position
 	movw	%ax, %dx
 	cmpb	%cl, %dh

@@ -883,7 +890,8 @@
 	orw	%di, %di
 	jnz	mtab1x
 	
-	leaw	modelist, %di			# Store standard modes:
+	movw	heap_start, %di			# Store standard modes:
+	movw	%di, modelist
 	movl	$VIDEO_80x25 + 0x50190000, %eax	# The 80x25 mode (ALL)
 	stosl
 	movb	adapter, %al			# CGA/MDA/HGA -- no more modes

@@ -929,13 +937,13 @@
 mtabe:
 
 #ifdef CONFIG_VIDEO_COMPACT
-	leaw	modelist, %si
+	movw	modelist, %si
 	movw	%di, %dx
 	movw	%si, %di
 cmt1:	cmpw	%dx, %si			# Scan all modes
 	jz	cmt2
 
-	leaw	modelist, %bx			# Find in previous entries
+	movw	modelist, %bx			# Find in previous entries
 	movw	2(%si), %cx
 cmt3:	cmpw	%bx, %si
 	jz	cmt4

@@ -957,7 +965,8 @@
 
 	movw	$ASK_VGA, (%di)			# End marker
 	movw	%di, mt_end
-mtab1:	leaw	modelist, %si			# SI=mode list, DI=list end
+	movw	%di, heap_start
+mtab1:	movw	modelist, %si			# SI=mode list, DI=list end
 ret0:	ret
 
 # Modes usable on all standard VGAs

@@ -1932,3 +1941,5 @@
 adapter:	.byte	0	# Video adapter: 0=CGA/MDA/HGA,1=EGA,2=VGA
 video_segment:	.word	0xb800	# Video memory segment
 force_size:	.word	0	# Use this size instead of the one in BIOS vars
+modelist:	.word	0	# Start of modelist on the heap
+heap_start:	.word	0	# low heap address

diff -uNr linux-2.5.12.boot.heap/arch/i386/boot/compressed/head.S linux-2.5.12.boot.clean_32bit_entries/arch/i386/boot/compressed/head.S
@@ -25,24 +25,30 @@
 
 #include <linux/linkage.h>
 #include <asm/segment.h>
+#include <asm/boot.h>
 
 	.globl startup_32
 	
 startup_32:
 	cld
 	cli
-	movl $(__KERNEL_DS),%eax
-	movl %eax,%ds
-	movl %eax,%es
-	movl %eax,%fs
-	movl %eax,%gs
 
-	lss stack_start,%esp
-	xorl %eax,%eax
-1:	incl %eax		# check that A20 really IS enabled
-	movl %eax,0x000000	# loop forever if it isn't
-	cmpl %eax,0x100000
-	je 1b
+	/*
+	 * Save the initial registers
+	 */
+	movl %eax, eax
+	movl %ebx, ebx
+	movl %ecx, ecx
+	movl %edx, edx
+	movl %esi, esi
+	movl %edi, edi
+	movl %esp, esp
+	movl %ebp, ebp
+
+	/*
+	 * Setup the stack
+	 */
+	movl stack_start, %esp
 
 /*
  * Initialize eflags.  Some BIOS's leave bits like NT set.  This would

@@ -66,16 +72,10 @@
  */
 	subl $16,%esp	# place for structure on the stack
 	movl %esp,%eax
-	pushl %esi	# real mode pointer as second arg
 	pushl %eax	# address of structure as first arg
 	call decompress_kernel
-	orl  %eax,%eax 
-	jnz  3f
-	popl %esi	# discard address
-	popl %esi	# real mode pointer
-	xorl %ebx,%ebx
-	ljmp $(__KERNEL_CS), $0x100000
-
+	orl  %eax,%eax
+	jz out
 /*
  * We come here, if we were loaded high.
  * We need to move the move-in-place routine down to 0x1000

@@ -83,8 +83,21 @@
  * which we got from the stack.
  */
 3:
-	movl $move_routine_start,%esi
-	movl $0x1000,%edi
+	/* Relocate the move routine */
+	movl $move_routine_start,%esi	#src
+	movl %eax,%edi			#dest
+	movl %eax, %ebp                 #saved dest
+	movl %edi, %eax 
+	subl %esi, %eax			# The relocation factor
+	addl %eax, reloc1
+	addl %eax, reloc2
+	addl %eax, reloc3
+	addl %eax, reloc4
+	addl %eax, reloc5
+	addl %eax, reloc6
+	addl %eax, reloc7
+	addl %eax, reloc8
+	addl %eax, reloc9
 	movl $move_routine_end,%ecx
 	subl %esi,%ecx
 	addl $3,%ecx

@@ -93,20 +106,23 @@
 	rep
 	movsl
 
+	/* Load it's arguments and jump to the move routine */
 	popl %esi	# discard the address
-	popl %ebx	# real mode pointer
 	popl %esi	# low_buffer_start
 	popl %ecx	# lcount
 	popl %edx	# high_buffer_start
 	popl %eax	# hcount
-	movl $0x100000,%edi
+	movl $HIGH_BASE,%edi
 	cli		# make sure we don't get interrupted
-	ljmp $(__KERNEL_CS), $0x1000 # and jump to the move routine
+	jmpl *%ebp
 
 /*
  * Routine (template) for moving the decompressed kernel in place,
- * if we were high loaded. This _must_ PIC-code !
+ * if we were high loaded. This _must_ be PIC-code !
+ * Or it must be anotated with lables so it can be manually relocated.
  */
+	.globl move_routine_start, move_routine_end
+	.balign 4
 move_routine_start:
 	movl %ecx,%ebp
 	shrl $2,%ecx

@@ -122,7 +138,35 @@
 	shrl $2,%ecx
 	rep
 	movsl
-	movl %ebx,%esi	# Restore setup pointer
-	xorl %ebx,%ebx
-	ljmp $(__KERNEL_CS), $0x100000
+out:
+	.byte 0xa1		# movl eax,  %eax
+reloc1:	.long eax
+	.byte 0x8b, 0x1d	# movl ebx,  %ebx
+reloc2:	.long ebx
+	.byte 0x8b, 0x0d	# movl ecx,  %ecx
+reloc3:	.long ecx
+	.byte 0x8b, 0x15	# movl edx, %edx
+reloc4:	.long edx
+	.byte 0x8b, 0x35	# movl esi, %esi
+reloc5:	.long esi
+	.byte 0x8b, 0x3d	# movl edi, %edi
+reloc6:	.long edi
+	.byte 0x8b, 0x25	# movl esp, %esp
+reloc7:	.long esp
+	.byte 0x8b, 0x2d	# movl ebp, %ebp
+reloc8:	.long ebp
+	.byte 0xff, 0x25	# jmpl *(kernel_start)
+reloc9:	.long kernel_start
+	.balign 4
+ENTRY(initial_regs)
+eax:	.long 0x12345678 /* eax */
+ebx:	.long 0x12345678 /* ebx */
+ecx:	.long 0x12345678 /* ecx */
+edx:	.long 0x12345678 /* edx */
+esi:	.long 0x12345678 /* esi */
+edi:	.long 0x12345678 /* edi */
+esp:	.long 0x12345678 /* esp */
+ebp:	.long 0x12345678 /* ebp */
+kernel_start:
+	.long HIGH_BASE
 move_routine_end:

diff -uNr linux-2.5.12.boot.heap/arch/i386/boot/setup.S linux-2.5.12.boot.clean_32bit_entries/arch/i386/boot/setup.S
@@ -67,6 +67,12 @@
 
 #define DELTA_BOOTSECT 512
 
+/* Segments used by setup.S */
+#define __SETUP_CS      0x10
+#define __SETUP_DS      0x18
+#define __SETUP_REAL_CS 0x20
+#define __SETUP_REAL_DS 0x28
+
 INITSEG  = DEF_INITSEG		# 0x9000, we move boot here, out of the way
 SYSSEG   = DEF_SYSSEG		# 0x1000, system loaded at 0x10000 (65536).
 SETUPSEG = DEF_SETUPSEG		# 0x9020, this is the current segment

@@ -798,13 +804,22 @@
 	jmp	flush_instr
 
 flush_instr:
-	xorw	%bx, %bx			# Flag to indicate a boot
 	xorl	%esi, %esi			# Pointer to real-mode code
 	movw	%cs, %si
 	subw	$DELTA_INITSEG, %si
 	shll	$4, %esi			# Convert to 32-bit pointer
+	movl	$ENTRY16, %ebp			# Magic to indicate 16bit entry
+
+# Setup the data segments
+	movw	$(__SETUP_DS), %ax
+	movw	%ax, %ds
+	movw	%ax, %es
+	movw	%ax, %fs
+	movw	%ax, %gs
+	movw	%ax, %ss
+
 # NOTE: For high loaded big kernels we need a
-#	jmpi    0x100000,__KERNEL_CS
+#	jmpi    0x100000,__SETUP_CS
 #
 #	but we yet haven't reloaded the CS register, so the default size 
 #	of the target offset still is 16 bit.

@@ -815,7 +830,7 @@
 	.byte 0x66, 0xea			# prefix + jmpi-opcode
 code32:	.long	0x1000				# will be set to 0x100000
 						# for big kernels
-	.word	__KERNEL_CS
+	.word	__SETUP_CS
 
 # Here's a bunch of information about your current kernel..
 kernel_version:	.ascii	UTS_RELEASE

259 lines not on this page · raw message

diff -uNr linux-2.5.12.boot.heap/arch/i386/kernel/trampoline.S linux-2.5.12.boot.clean_32bit_entries/arch/i386/kernel/trampoline.S
@@ -12,10 +12,6 @@
  *	In fact we don't actually need a stack so we don't
  *	set one up.
  *
- *	We jump into the boot/compressed/head.S code. So you'd
- *	better be running a compressed kernel image or you
- *	won't get very far.
- *
  *	On entry to trampoline_data, the processor is in real mode
  *	with 16-bit addressing and 16-bit data.  CS has some value
  *	and IP is zero.  Thus, data addresses need to be absolute

@@ -23,12 +19,16 @@
  *
  *	If you work on this file, check the object module with objdump
  *	--full-contents --reloc to make sure there are no relocation
- *	entries except for the gdt one..
+ *	entries except for gdt & secondary_startup_32..
  */
 
 #include <linux/linkage.h>
+#include <linux/threads.h>
 #include <asm/segment.h>
 #include <asm/page.h>
+#include <asm/desc.h>
+
+#define GDT_ENTRIES	(__TSS(NR_CPUS))
 
 .data
 

@@ -42,7 +42,6 @@
 	mov	%cs, %ax	# Code and data in the same place
 	mov	%ax, %ds
 
-	mov	$1, %bx		# Flag an SMP trampoline
 	cli			# We should be safe anyway
 
 	movl	$0xA5A5A5A5, trampoline_data - r_base

@@ -56,15 +55,16 @@
 	lmsw	%ax		# into protected mode
 	jmp	flush_instr
 flush_instr:
-	ljmpl	$__KERNEL_CS, $0x00100000
-			# jump to startup_32 in arch/i386/kernel/head.S
+		# jump to secondary_startup_32 in arch/i386/kernel/head.S
+	ljmpl	$__KERNEL_CS, $(secondary_startup_32 - __PAGE_OFFSET)
+	
 
 idt_48:
 	.word	0			# idt limit = 0
 	.word	0, 0			# idt base = 0L
 
 gdt_48:
-	.word	0x0800			# gdt limit = 2048, 256 GDT entries
+	.word	GDT_ENTRIES*8-1		# gdt limit
 	.long	gdt_table-__PAGE_OFFSET	# gdt base = gdt (first SMP CPU)
 
 .globl trampoline_end

diff -uNr linux-2.5.12.boot.clean_32bit_entries/arch/i386/boot/compressed/Makefile linux-2.5.12.boot.footprint/arch/i386/boot/compressed/Makefile
@@ -9,8 +9,6 @@
 
 OBJECTS = $(HEAD) misc.o
 
-ZLDFLAGS = -e startup_32
-
 #
 # ZIMAGE_OFFSET is the load offset of the compression loader
 # BZIMAGE_OFFSET is the load offset of the high loaded compression loader

@@ -18,8 +16,8 @@
 ZIMAGE_OFFSET = 0x1000
 BZIMAGE_OFFSET = 0x100000
 
-ZLINKFLAGS = -Ttext $(ZIMAGE_OFFSET) $(ZLDFLAGS)
-BZLINKFLAGS = -Ttext $(BZIMAGE_OFFSET) $(ZLDFLAGS)
+ZLINKFLAGS = -Ttext $(ZIMAGE_OFFSET) -T vmlinuz.lds
+BZLINKFLAGS = -Ttext $(BZIMAGE_OFFSET) -T vmlinuz.lds 
 
 all: vmlinux
 

@@ -42,7 +40,7 @@
 	rm -f $$tmppiggy $$tmppiggy.gz $$tmppiggy.lnk; \
 	$(OBJCOPY) $(SYSTEM) $$tmppiggy; \
 	gzip -f -9 < $$tmppiggy > $$tmppiggy.gz; \
-	echo "SECTIONS { .data : { input_len = .; LONG(input_data_end - input_data) input_data = .; *(.data) input_data_end = .; }}" > $$tmppiggy.lnk; \
+	echo "SECTIONS { .input : { *(.data) }}" > $$tmppiggy.lnk; \
 	$(LD) -r -o piggy.o -b binary $$tmppiggy.gz -b elf32-i386 -T $$tmppiggy.lnk; \
 	rm -f $$tmppiggy $$tmppiggy.gz $$tmppiggy.lnk
 

diff -uNr linux-2.5.12.boot.clean_32bit_entries/arch/i386/boot/compressed/head.S linux-2.5.12.boot.footprint/arch/i386/boot/compressed/head.S
@@ -30,6 +30,20 @@
 	.globl startup_32
 	
 startup_32:
+	jmp 1f
+	.balign		4
+	.globl input_addr, input_len, output_overhang
+	.globl kernel_base, kernel_memsz, kernel_filesz
+	.globl unzip_memsz, unzip_filesz
+input_addr:		.long input_data
+input_len:		.long input_data_len
+output_overhang:	.long input_data_len # Will be set to 8 later...
+kernel_base:		.long HIGH_BASE
+kernel_memsz:		.long 0
+kernel_filesz:		.long 0
+unzip_memsz:		.long _end
+unzip_filesz:		.long _edata
+1:	
 	cld
 	cli
 

@@ -44,6 +58,18 @@
 	movl %edi, edi
 	movl %esp, esp
 	movl %ebp, ebp
+
+	/* 
+	 * Move the input data off the bss segment
+	 */
+	std
+	movl $input_data_end -1, %esi
+	movl %esi, %edi
+	addl $input_data_shift, %edi
+	movl $input_data_len, %ecx
+	rep movsb
+	cld
+	addl $input_data_shift, input_addr
 
 	/*
 	 * Setup the stack

diff -uNr linux-2.5.12.boot.clean_32bit_entries/arch/i386/boot/compressed/vmlinuz.lds linux-2.5.12.boot.footprint/arch/i386/boot/compressed/vmlinuz.lds
@@ -0,0 +1,29 @@
+/* ld script to make compressed i386 Linux kernel
+ */
+OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
+OUTPUT_ARCH(i386)
+ENTRY(startup_32)
+SECTIONS
+{
+	. = 0x1000;
+	_text = .;			/* Text and read-only data */
+	.text : { *(.text) } = 0x9090
+	_etext = .;			/* End of text section */
+	.rodata : { *(.rodata) *(.rodata.*) }
+	.data : { 
+		*(.data) 
+		
+	}
+	_edata = .;			/* End of data section */
+	.bss _edata : { *(.bss) }
+	_end = .;
+	.input _edata : { 
+		input_data = . ;
+		*(.input)
+		input_data_end = . ;
+	}
+	input_data_len = input_data_end - input_data;
+	input_data_shift = _end - _edata;
+
+	/DISCARD/ : { *(*) }
+}		

diff -uNr linux-2.5.12.boot.clean_32bit_entries/arch/i386/boot/setup.S linux-2.5.12.boot.footprint/arch/i386/boot/setup.S
@@ -109,6 +109,8 @@
 # flags, unused bits must be zero (RFU) bit within loadflags
 loadflags:
 LOADED_HIGH	= 1			# If set, the kernel is loaded high
+STAY_PUT        = 0x40                  # If set, the loader doesn't expect
+                                        # us to relocate anything
 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

@@ -165,7 +167,11 @@
 					# The highest safe address for
 					# the contents of an initrd
 
-# variables private to setup.S (not for bootloaders)
+# variables private to the kernel (not for bootloaders)
+pad2:		.long	0
+real_base:	.long	REAL_BASE	# Location of real mode kernel
+real_memsz:				# Memory usage of real mode kernel
+		.long	(_esetup_heap - _setup) + DELTA_BOOTSECT
 real_filesz:				# Datasize of the real mode kernel
 		.long (_esetup - _setup) + DELTA_BOOTSECT
 trampoline:	call	start_of_setup

@@ -300,6 +306,15 @@
 #endif /* __BIG_KERNEL__ */
 
 loader_ok:
+# Get base memory size
+# The size in kilobytes is returned in %ax
+# There shouldn't be any subfunctions but just
+# in case we clear eax and ecx
+	xorl	%eax, %eax
+	xorl	%ecx, %ecx
+	int	$0x12
+	movw	%ax, (0x1e4)
+	
 # Get memory size (extended mem, kB)
 
 	xorl	%eax, %eax

@@ -607,12 +622,13 @@
 # then we load the segment descriptors
 	movw	%cs, %ax			# aka SETUPSEG
 	movw	%ax, %ds
-		
+
 # Check whether we need to be downward compatible with version <=201
+# We don't relocate if STAY_PUT is specified or we have a 202 cmd_line
+	testb  	$STAY_PUT, loadflags
+	jnz	end_move_self
 	cmpl	$0, cmd_line_ptr
 	jne	end_move_self		# loader uses version >=202 features
-	cmpb	$0x20, type_of_loader
-	je	end_move_self		# bootsect loader, we know of it
 
 # Boot loader doesnt support boot protocol version 2.02.
 # If we have our code not at 0x90000, we need to move it there now.

@@ -860,6 +876,7 @@
 	jnz	bootsect_second
 
 	movb	$0x20, %cs:type_of_loader
+	orb	$STAY_PUT, %cs:loadflags
 	movw	%es, %ax
 	shrw	$4, %ax
 	movb	%ah, %cs:bootsect_src_base+2

diff -uNr linux-2.5.12.boot.footprint/Makefile linux-2.5.12.boot.build/Makefile
@@ -93,15 +93,6 @@
 AFLAGS := -D__ASSEMBLY__ $(CPPFLAGS)
 
 #
-# ROOT_DEV specifies the default root-device when making the image.
-# This can be either FLOPPY, CURRENT, /dev/xxxx or empty, in which case
-# the default of FLOPPY is used by 'build'.
-# This is i386 specific.
-#
-
-export ROOT_DEV = CURRENT
-
-#
 # If you want to preset the SVGA mode, uncomment the next line and
 # set SVGA_MODE to whatever number you want.
 # Set it to -DSVGA_MODE=NORMAL_VGA if you just want the EGA/VGA mode.

diff -uNr linux-2.5.12.boot.footprint/arch/i386/boot/Makefile linux-2.5.12.boot.build/arch/i386/boot/Makefile
@@ -12,13 +12,11 @@
 		$(TOPDIR)/include/linux/autoconf.h \
 		$(TOPDIR)/include/asm/boot.h
 
-zImage: $(CONFIGURE) bootsect setup compressed/vmlinux tools/build
-	$(OBJCOPY) compressed/vmlinux compressed/vmlinux.out
-	tools/build bootsect setup compressed/vmlinux.out $(ROOT_DEV) > zImage
-
-bzImage: $(CONFIGURE) bbootsect bsetup compressed/bvmlinux tools/build
-	$(OBJCOPY) compressed/bvmlinux compressed/bvmlinux.out
-	tools/build -b bbootsect bsetup compressed/bvmlinux.out $(ROOT_DEV) > bzImage
+zImage: $(CONFIGURE) tools/build $(TOPDIR)/vmlinux realmode compressed/vmlinux 
+	tools/build $(TOPDIR)/vmlinux realmode compressed/vmlinux zImage
+
+bzImage: $(CONFIGURE) tools/build $(TOPDIR)/vmlinux brealmode compressed/bvmlinux 
+	tools/build -b $(TOPDIR)/vmlinux brealmode compressed/bvmlinux bzImage
 
 compressed/vmlinux: $(TOPDIR)/vmlinux
 	@$(MAKE) -C compressed vmlinux

@@ -39,49 +37,43 @@
 install: $(CONFIGURE) $(BOOTIMAGE)
 	sh -x ./install.sh $(KERNELRELEASE) $(BOOTIMAGE) $(TOPDIR)/System.map "$(INSTALL_PATH)"
 
-tools/build: tools/build.c
+tools/build: tools/build.c $(TOPDIR)/include/linux/version.h $(TOPDIR)/include/linux/compile.h $(TOPDIR)/include/asm-i386/boot.h
 	$(HOSTCC) $(HOSTCFLAGS) -o $@ $< -I$(TOPDIR)/include
 
-bootsect: bootsect.o
-	$(LD) -Ttext 0x0 -s --oformat binary -o $@ $<
-
 bootsect.o: bootsect.s
 	$(AS) -o $@ $<
 
 bootsect.s: bootsect.S Makefile $(BOOT_INCL)
 	$(CPP) $(CPPFLAGS) -traditional $(SVGA_MODE) $(RAMDISK) $< -o $@
 
-bbootsect: bbootsect.o
-	$(LD) -Ttext 0x0 -s --oformat binary $< -o $@
-
 bbootsect.o: bbootsect.s
 	$(AS) -o $@ $<
 
 bbootsect.s: bootsect.S Makefile $(BOOT_INCL)
 	$(CPP) $(CPPFLAGS) -D__BIG_KERNEL__ -traditional $(SVGA_MODE) $(RAMDISK) $< -o $@
 
-setup: setup.o
-	$(LD) -Ttext 0x0 -s --oformat binary -e begtext -o $@ $<
-
 setup.o: setup.s
 	$(AS) -o $@ $<
 
 setup.s: setup.S video.S Makefile $(BOOT_INCL) $(TOPDIR)/include/linux/version.h $(TOPDIR)/include/linux/compile.h
 	$(CPP) $(CPPFLAGS) -D__ASSEMBLY__ -traditional $(SVGA_MODE) $(RAMDISK) $< -o $@
 
-bsetup: bsetup.o
-	$(LD) -Ttext 0x0 -s --oformat binary -e begtext -o $@ $<
-
 bsetup.o: bsetup.s
 	$(AS) -o $@ $<
 
 bsetup.s: setup.S video.S Makefile $(BOOT_INCL) $(TOPDIR)/include/linux/version.h $(TOPDIR)/include/linux/compile.h
 	$(CPP) $(CPPFLAGS) -D__BIG_KERNEL__ -D__ASSEMBLY__ -traditional $(SVGA_MODE) $(RAMDISK) $< -o $@
 
+realmode: bootsect.o setup.o
+	$(LD) -T realmode.lds -o $@ $^
+
+brealmode: bbootsect.o bsetup.o
+	$(LD) -T realmode.lds -o $@ $^
+
 dep:
 
 clean:
 	rm -f tools/build
-	rm -f setup bootsect zImage compressed/vmlinux.out
-	rm -f bsetup bbootsect bzImage compressed/bvmlinux.out
+	rm -f realmode zImage
+	rm -f brealmode bzImage
 	@$(MAKE) -C compressed clean

diff -uNr linux-2.5.12.boot.footprint/arch/i386/boot/bootsect.S linux-2.5.12.boot.build/arch/i386/boot/bootsect.S
@@ -54,7 +54,7 @@
 #endif
 
 .code16
-.text
+.section ".bootsect", "ax", @progbits
 
 .global _start
 _start:

diff -uNr linux-2.5.12.boot.footprint/arch/i386/boot/realmode.lds linux-2.5.12.boot.build/arch/i386/boot/realmode.lds
@@ -0,0 +1,18 @@
+OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
+ENTRY(_start)
+OUTPUT_ARCH(i386)
+SECTIONS
+{
+	.bootsect 0 : AT(0x10000) {
+		*(.bootsect)
+	}
+	.setup 0 : AT(LOADADDR(.bootsect) + SIZEOF(.bootsect)) {
+		*(.setup)
+	}
+	.setup.heap SIZEOF(.setup) : AT(LOADADDR(.setup) + SIZEOF(.setup)) {
+		*(.setup.heap)
+	}
+	/DISCARD/ : {
+		*(*)
+	}
+}

diff -uNr linux-2.5.12.boot.footprint/arch/i386/boot/setup.S linux-2.5.12.boot.build/arch/i386/boot/setup.S
@@ -83,7 +83,7 @@
 .code16
 .globl _setup, _esetup
 
-.text
+.section ".setup", "ax", @progbits
 _setup:	
 
 start:

@@ -174,6 +174,9 @@
 		.long	(_esetup_heap - _setup) + DELTA_BOOTSECT
 real_filesz:				# Datasize of the real mode kernel
 		.long (_esetup - _setup) + DELTA_BOOTSECT
+kern_base:	.long	KERNEL_START	# Kernel load address
+kern_memsz:	.long	0x00000000	# Kernel memory usage
+kern_filesz:	.long	0x00000000	# Kernel datasize
 trampoline:	call	start_of_setup
 		# Don't let the E820 map overlap code
 		. = (E820MAP - DELTA_BOOTSECT) + (E820MAX * E820ENTRY_SIZE)

diff -uNr linux-2.5.12.boot.footprint/arch/x86_64/boot/Makefile linux-2.5.12.boot.build/arch/x86_64/boot/Makefile
@@ -14,11 +14,11 @@
 
 zImage: $(CONFIGURE) bootsect setup compressed/vmlinux tools/build
 	$(OBJCOPY) compressed/vmlinux compressed/vmlinux.out
-	tools/build bootsect setup compressed/vmlinux.out $(ROOT_DEV) > zImage
+	tools/build bootsect setup compressed/vmlinux.out CURRENT > zImage
 
 bzImage: $(CONFIGURE) bbootsect bsetup compressed/bvmlinux tools/build
 	$(OBJCOPY) compressed/bvmlinux compressed/bvmlinux.out
-	tools/build -b bbootsect bsetup compressed/bvmlinux.out $(ROOT_DEV) > bzImage
+	tools/build -b bbootsect bsetup compressed/bvmlinux.out CURRENT > bzImage
 
 bzImage-padded: bzImage
 	dd if=/dev/zero bs=1k count=70 >> bzImage

diff -uNr linux-2.5.12.boot.build/Documentation/i386/boot.txt linux-2.5.12.boot.proto/Documentation/i386/boot.txt
@@ -4,6 +4,9 @@
 		    H. Peter Anvin <[email protected]>
 			Last update 2002-01-01
 
+		Eric Biederman <[email protected]>
+		       Last update 28 April 2002
+
 On the i386 platform, the Linux kernel uses a rather complicated boot
 convention.  This has evolved partially due to historical aspects, as
 well as the desire in the early days to have the kernel itself be a

@@ -35,6 +38,14 @@
 		initrd address available to the bootloader.
 
 
+Protocol 2.04:  (Kernel 2.5.x) 
+		- Decompression in place (smaller load footpribnt)
+		  The overhead is now 72KB below 1MB && 8 bytes above 1MB
+		- 32bit entry point support
+		- Exported the load time memory usage.
+		- zImage now has a larger memory footprint than bzImage.
+		  should we just kill zImage?
+
 **** MEMORY LAYOUT
 
 The traditional memory map for the kernel loader, used for Image or

@@ -100,34 +111,42 @@
 
 The header looks like:
 
-Offset	Proto	Name		Meaning
+Offset  Proto  Name                  Meaning
 /Size
 
-01F1/1	ALL	setup_sects	The size of the setup in sectors
-01F2/2	ALL	root_flags	If set, the root is mounted readonly
-01F4/2	ALL	syssize		DO NOT USE - for bootsect.S use only
-01F6/2	ALL	swap_dev	DO NOT USE - obsolete
-01F8/2	ALL	ram_size	DO NOT USE - for bootsect.S use only
-01FA/2	ALL	vid_mode	Video mode control
-01FC/2	ALL	root_dev	Default root device number
-01FE/2	ALL	boot_flag	0xAA55 magic number
-0200/2	2.00+	jump		Jump instruction
-0202/4	2.00+	header		Magic signature "HdrS"
-0206/2	2.00+	version		Boot protocol version supported
-0208/4	2.00+	realmode_swtch	Boot loader hook (see below)
-020C/2	2.00+	start_sys	The load-low segment (0x1000) (obsolete)
-020E/2	2.00+	kernel_version	Pointer to kernel version string
-0210/1	2.00+	type_of_loader	Boot loader identifier
-0211/1	2.00+	loadflags	Boot protocol option flags
-0212/2	2.00+	setup_move_size	Move to high memory size (used with hooks)
-0214/4	2.00+	code32_start	Boot loader hook (see below)
-0218/4	2.00+	ramdisk_image	initrd load address (set by boot loader)
-021C/4	2.00+	ramdisk_size	initrd size (set by boot loader)
-0220/4	2.00+	bootsect_kludge	DO NOT USE - for bootsect.S use only
-0224/2	2.01+	heap_end_ptr	Free memory after setup end
-0226/2	N/A	pad1		Unused
-0228/4	2.02+	cmd_line_ptr	32-bit pointer to the kernel command line
-022C/4	2.03+	initrd_addr_max	Highest legal initrd address
+01F1/1  ALL    setup_sects           The size of the setup in sectors
+01F2/2  ALL    root_flags            If set, the root is mounted readonly
+01F4/2  ALL    syssize               DO NOT USE - for bootsect.S use only
+01F6/2  ALL    swap_dev              DO NOT USE - obsolete
+01F8/2  ALL    ram_size              DO NOT USE - for bootsect.S use only
+01FA/2  ALL    vid_mode              Video mode control
+01FC/2  ALL    root_dev              Default root device number
+01FE/2  ALL    boot_flag             0xAA55 magic number
+0200/2  2.00+  jump                  Jump instruction
+0202/4  2.00+  header_magic          Magic signature "HdrS"
+0206/2  2.00+  protocol_version      Boot protocol version supported
+0208/4  2.00+  realmode_swtch        Boot loader hook (see below)
+020C/2  2.00+  start_sys_seg         Segment the zImage kernel was loaded at (0x1000) (obsolete)
+020E/2  2.00+  kernel_version        Pointer to kernel version string
+0210/1  2.00+  type_of_loader        Boot loader identifier
+0211/1  2.00+  loadflags             Boot protocol option flags
+0212/2  2.00+  setup_move_size       Move to high memory size (used with hooks)
+0214/4  2.00+  code32_start          Boot loader hook (see below)
+0218/4  2.00+  initrd_start          initrd load address (set by boot loader)
+021C/4  2.00+  initrd_size           initrd size (set by boot loader)
+0220/4  2.00+  bootsect_kludge       DO NOT USE - for bootsect.S use only
+0224/2  2.01+  heap_end_ptr          Free memory after setup end
+0226/2  N/A    pad1                  Unused
+0228/4  2.02+  cmd_line_ptr          32-bit pointer to the kernel command line
+022C/4  2.03+  ramdisk_max           Highest legal initrd address
+0230/2  2.04+  entry32_off           offset of 32bit entry point
+0230/2  2.04+  internal_cmdline_off  offset of compiled in command line
+0234/4  2.04+  real_base             Default load address of real mode code
+0238/4  2.04+  real_memsz            Memory used @ real_base
+023C/4  2.04+  real_filesz           Amount of data loaded @ real_base
+0240/4  2.04+  kern_base             Kernel decompressor load address
+0244/4  2.04+  kern_memsz            Memory used @ kern_base
+0248/4  2.04+  kern_filesz           Amount of data loaeded @ kern_base
 
 For backwards compatibility, if the setup_sects field contains 0, the
 real value is 4.

@@ -180,8 +199,14 @@
   loadflags, heap_end_ptr:
 	If the protocol version is 2.01 or higher, enter the
 	offset limit of the setup heap into heap_end_ptr and set the
-	0x80 bit (CAN_USE_HEAP) of loadflags.  heap_end_ptr appears to
-	be relative to the start of setup (offset 0x0200).
+	0x80 bit (CAN_USE_HEAP) of loadflags.  heap_end_ptr is
+	relative to the start of setup (offset 0x0200).
+
+	If the protocol version is 2.04 or higher set the 0x40 bit
+	(STAY_PUT).  This explictly tells the real mode code that you
+	don't expect it to relocate itself to 0x90000.  No earlier
+	protocols versions look at this bit so it is safe to set it
+	unconditionally.
 
   setup_move_size: 
 	When using protocol 2.00 or 2.01, if the real mode

@@ -190,17 +215,20 @@
 	additional data (such as the kernel command line) moved in
 	addition to the real-mode kernel itself.
 
-  ramdisk_image, ramdisk_size:
+  initrd_start, initrd_size:
 	If your boot loader has loaded an initial ramdisk (initrd),
-	set ramdisk_image to the 32-bit pointer to the ramdisk data
-	and the ramdisk_size to the size of the ramdisk data.
+	set initrd_start to the 32-bit pointer to the ramdisk data
+	and the initrd_size to the size of the ramdisk data.
 
 	The initrd should typically be located as high in memory as
 	possible, as it may otherwise get overwritten by the early
 	kernel initialization sequence.	 However, it must never be
-	located above the address specified in the initrd_addr_max
+	located above the address specified in the ramdisk_max
 	field.	The initrd should be at least 4K page aligned.
 
+	With boot protocol 2.04 and above the initrd can be loaded
+	as low as kern_base + kern_memsz.
+
   cmd_line_ptr:
 	If the protocol version is 2.02 or higher, this is a 32-bit
 	pointer to the kernel command line.  The kernel command line

@@ -248,6 +276,11 @@
 	covered by setup_move_size, so you may need to adjust this
 	field.
 
+If the protocol version is 2.04 or higher a compiled in command line
+may be present.  If this is the case the passed command line is
+appended onto the tail of the compiled command line.  Assuming
+there is room.
+
 
 **** SAMPLE BOOT CONFIGURATION
 

@@ -269,8 +302,8 @@
 	if ( protocol >= 0x0200 ) {
 		type_of_loader = <type code>;
 		if ( loading_initrd ) {
-			ramdisk_image = <initrd_address>;
-			ramdisk_size = <initrd_size>;
+			initrd_start = <initrd_address>;
+			initrd_size = <initrd_size>;
 		}
 		if ( protocol >= 0x0201 ) {
 			heap_end_ptr = 0x9000 - 0x200;

@@ -436,3 +469,176 @@
 
 	After completing your hook, you should jump to the address
 	that was in this field before your boot loader overwrote it.
+
+
+**** THE COMPRESSED KERNEL HEADER
+
+As of boot protocol version 2.04 a header has been added to the
+compressed data, to reduce information loss.  Most bootloaders
+should never need to look at these fields.
+
+Offset  Proto  Name             Meaning
+/Size
+
+0000/4  2.04+  jump             Jump Instruction
+0004/4  2.04+  input_addr       Load address of compressed data
+0008/4  2.04+  input_len        Length of compressed data
+000C/4  2.04+  output_overhang  Extra bytes needed for inplace decompression
+0010/4  2.04+  kernel_base      Kernel load address
+0014/4  2.04+  kernel_filesz    Memory usage @ kernel_base     
+0018/4  2.04+  kernel_memsz     Data size @ kernel_base
+001C/4  2.04+  unzip_filesz     Decompressor code/data size
+0020/4  2.04+  unzip_memsz      Decompressor code memory usage
+
+**** DETAILED DESCRIPTION OF FIELDS
+
+  entry32_off:
+	The unsigned offset of the 32bit entry point from the real
+	mode kernel. For boot protocols 2.03 or earlier, this field is
+	not present, and there is no 32bit entry point.
+
+	The 32bit entry point is a mechanism for entering the kernel
+	without doing 16bit PC BIOS calls.  Very useful for systems
+	with alternative firmware implementations.
+
+	A bootloader using the 32bit entry point should verify that
+	there are real_memsz bytes available at real_base (real_base
+	remains relocatable in bzImages).  And that there kern_memsz
+	bytes available at kern_base.  For zImages you should also
+	verify that there are kernel_memsz bytes available at
+	kernel_base.
+
+	Verifing there is enough memory for the kernel to load is
+	necessary for using the 32bit entry point, and suggested for
+	the 16bit entry point.  In the case of the 32bit entry point
+	the kernel has no ability to talk to whatever weird firmware you
+	have until it is fully loaded.
+
+	The 32bit entry point makes the following assumptions.  You
+	are calling it protected mode.  Paging is disabled.  All
+	segment registers are loaded with a 32bit segment with a base
+	of 0, and a limit of 0xFFFFFFFF (limitless).  Either %esp == 0
+	and you are using the default real_base or %esp points to a
+	stack large enough to hold at least 12 new bytes of data.
+
+
+  internal_cmdline_off:
+	The offset of the null terminated compiled in command line
+	from the real mode kernel.   For boot protocols 2.03 or
+	earlier this field is not present, and there is no built in
+	command line.  The memory from internal_cmdline_off to
+	real_filesz is reserved for the compiled in command_line.  An
+	external utility may modify this command line.
+
+	To change the maximum size of the compiled in command line several
+	variables need to be modified.  real_filesz to indicate the
+	new maximum size.  setup_sects to indicate if the number of
+	sectors needed for the realmode kernel changes.  
+
+	A heap is maintained between real_filesz and real_memsz/heap_end_ptr.
+	Increasing the size of the heap is not a problem, decreasing
+	it is.  So when changing the real_filesz, real_memsz and
+	heap_end_ptr should also be changed.
+
+  input_addr/input_len:
+	The kernel is loaded into memory in compressed form.
+	input_addr is the location where the compressed data is
+	loaded, and input_len is the count of how many bytes of
+	compressed data there are.
+	
+	These two variables allow an external program to inspect a
+	bzImage and find the compressed data.  This is mostly of use
+	to build.c as it computes output_overhang but other programs
+	may find it useful as well.
+
+  output_overhang:
+	Most decompression algorithms may transformed into near
+	in-place algorithms by simply overlapping the compressed data
+	and the decompressed data buffers.  For a particular
+	decompression algorithm then the question becomes how much
+	overlap is safe.  More practically how much must the
+	compressed data stick out from the end of the decompressed
+	data buffer for this technique to work.
+
+	output_overhang is that amount the compressed data buffer
+	must extend beyond the decompressed data buffer for
+	decompression in place to work for the linux kernel.
+
+	build.c is responsible for computing this number.  For
+	gzip typically this number is 8 (file length and checksum).
+	But in pathological cases it may be worse.
+
+  real_base, real_memsz, real_filesz, 
+  kern_base, kern_memsz, kern_filesz,
+  kernel_base, kernel_memsz, kernel_filesz,
+  unzip_memsz, unzip_filesz,
+
+	Up to this point building a zImage or a bzImage has been a
+	very lossy process.  The introduction of these variables
+        attempts to rectify that situation.  They document exactly
+	which pieces of memory, the kernel uses during the boot
+	process, and they indicate exactly how large the various data
+	segments of the kernel are.  It is now possible to create a
+	lossless transformation to and from a static ELF executable.
+
+	Program segments are described with 3 variables.  The base
+	address where the segment is loaded in memory.  The file size
+	which records the amount of data in the input file that is
+	loaded into memory.  The memory size which is greater than or
+	equal to the file size and records how much memory this
+	program segment consumes.
+
+	base   +-----------+
+	       | code/data |
+	filesz +-----------+
+	       |  bss      |
+	memsz  +-----------+
+
+	The real program segment (real_base, real_filesz, real_memsz)
+	describes the memory usage of the real mode code from 4KB to
+	640KB.  The real code segment and the command line must be  
+	located somewhere in this range.
+
+	The compressed kernel segment (kern_base, kern_filesz,
+	kern_memsz) describes the memory usage of the compressed
+	kernel.  For a zImage this is memory below 1MB for a bzImage
+	this is memory starting at 1MB.
+
+	For bzImages it is sufficient to look at the real program
+	segment, and the compressed kernel segment to get the entire
+	boottime memory usage of the kernel.  real_memsz is increased
+	to also document the decompressors real memory usage, and the
+	kern_memsz value is increased to document the decompressed
+	kernels memory usage.
+
+	You can look at heap_end_ptr to get the actual memory
+	footprint of the real mode segment.  Just the decompressors
+	memory footprint is kern_base + kernel_filesz +
+	output_overhang, if unzip_memsz bytes are available of real
+	memory, and kern_base + kernel_filesz + output_overhang +
+	unzip_memsz bytes otherwise.
+	
+	The decompressed kernel segment (kernel_base, kernel_filesz,
+	kernel_memsz) describes the memory usage of the decompresed
+	kernel (essentially vmlinux). 
+
+	The decompressor segment (load_address, unzip_filesz, unzip_memsz)
+	describes the memory usage of the kernel decompressor,
+	not counting the compressed data.
+
+	The real program segment describes memory in the range
+	4KB (0x1000) to 640KB (0xa0000) that the real mode kernel
+	uses.  real_base may be moved lower or higher in memory if
+	there is a memory conflict with another address.  When doing
+	so the following considerations should apply.
+
+		For a zImage the range [real_base, real_base +
+		real_memsz) should not overlap the range [ kern_base,
+		kern_base + kern_memsz].
+
+		Ensure that the range [real_base, real_base +
+		real_memsz) is within the range [ 0x1000, 0xa0000).
+		
+	With this information it becomes safe to statically relocate
+	the real mode kernel as well as to dynamically relocate the
+	real_mode kernel.

diff -uNr linux-2.5.12.boot.build/arch/i386/Config.help linux-2.5.12.boot.proto/arch/i386/Config.help
@@ -803,6 +803,12 @@
   a work-around for a number of buggy BIOSes. Switch this option on if
   your computer crashes instead of powering off properly.
 
+CONFIG_CMDLINE
+  Generally it is best to pass command line parameters via the
+  bootloader but there are times it is convinient not to do this.
+  This allows you to hard code a default kernel command line, whatever
+  the bootloader passes will be appended to it.
+
 CONFIG_X86_MCE
   Machine Check Exception support allows the processor to notify the
   kernel if it detects a problem (e.g. overheating, component failure).

diff -uNr linux-2.5.12.boot.build/arch/i386/boot/realmode.lds linux-2.5.12.boot.proto/arch/i386/boot/realmode.lds
@@ -1,5 +1,5 @@
 OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
-ENTRY(_start)
+ENTRY(entry32)
 OUTPUT_ARCH(i386)
 SECTIONS
 {

291 lines not on this page · raw message

diff -uNr linux-2.5.12.boot.build/arch/i386/config.in linux-2.5.12.boot.proto/arch/i386/config.in
@@ -282,6 +282,7 @@
    bool '    Use real mode APM BIOS call to power off' CONFIG_APM_REAL_MODE_POWER_OFF
 fi
 
+string 'Initial kernel command line' CONFIG_CMDLINE ""
 endmenu
 
 source drivers/mtd/Config.in

diff -uNr linux-2.5.12.boot.proto/arch/i386/Config.help linux-2.5.12.boot.linuxbios/arch/i386/Config.help
@@ -803,6 +803,22 @@
   a work-around for a number of buggy BIOSes. Switch this option on if
   your computer crashes instead of powering off properly.
 
+LinuxBIOS support
+CONFIG_LINUXBIOS
+  LinuxBIOS is an alternative GPL'd firmware initially for x86
+  compatible machines.  LinuxBIOS attempts to be a simple and as fast
+  as possible, and is initially optimized for linux.  The interface to
+  the OS is a table at the beginning of memory.  Which should make the
+  inevitable firmware bugs easier to work around, as should the source
+  code :)  A goal of this table is to provide enough information so
+  that any OS but especially linux does not need to have motherboard
+  specific knowledge.
+
+  This first release only provides LinuxBIOS detection (by detecting
+  it's table) and memory size detection. 
+
+  For more information on LinuxBIOS see http://www.linuxbios.org
+
 CONFIG_CMDLINE
   Generally it is best to pass command line parameters via the
   bootloader but there are times it is convinient not to do this.

diff -uNr linux-2.5.12.boot.proto/arch/i386/config.in linux-2.5.12.boot.linuxbios/arch/i386/config.in
@@ -206,6 +206,7 @@
    fi
 fi
 
+bool 'LinuxBIOS support' CONFIG_LINUXBIOS
 endmenu
 
 mainmenu_option next_comment

diff -uNr linux-2.5.12.boot.proto/arch/i386/defconfig linux-2.5.12.boot.linuxbios/arch/i386/defconfig
@@ -119,6 +119,7 @@
 CONFIG_BINFMT_MISC=y
 CONFIG_PM=y
 # CONFIG_APM is not set
+# CONFIG_LINUXBIOS is not set
 
 #
 # Memory Technology Devices (MTD)

diff -uNr linux-2.5.12.boot.proto/arch/i386/kernel/Makefile linux-2.5.12.boot.linuxbios/arch/i386/kernel/Makefile
@@ -42,6 +42,7 @@
 obj-$(CONFIG_SMP)		+= smp.o smpboot.o trampoline.o
 obj-$(CONFIG_X86_LOCAL_APIC)	+= mpparse.o apic.o nmi.o
 obj-$(CONFIG_X86_IO_APIC)	+= io_apic.o
+obj-$(CONFIG_LINUXBIOS)		+= linuxbios.o
 ifdef CONFIG_VISWS
 obj-y += setup-visws.o
 obj-$(CONFIG_X86_VISWS_APIC)	+= visws_apic.o

diff -uNr linux-2.5.12.boot.linuxbios/arch/i386/Makefile linux-2.5.12.boot.elf/arch/i386/Makefile
@@ -119,6 +119,9 @@
 bzImage: vmlinux
 	@$(MAKEBOOT) bzImage
 
+bzElf: vmlinux
+	@$(MAKEBOOT) bzElf
+
 compressed: zImage
 
 zlilo: vmlinux

diff -uNr linux-2.5.12.boot.linuxbios/arch/i386/boot/Makefile linux-2.5.12.boot.elf/arch/i386/boot/Makefile
@@ -18,6 +18,9 @@
 bzImage: $(CONFIGURE) tools/build $(TOPDIR)/vmlinux brealmode compressed/bvmlinux 
 	tools/build -b $(TOPDIR)/vmlinux brealmode compressed/bvmlinux bzImage
 
+bzElf: $(CONFIGURE) tools/build $(TOPDIR)/vmlinux brealmode compressed/bvmlinux 
+	tools/build -e -b $(TOPDIR)/vmlinux brealmode compressed/bvmlinux bzElf
+
 compressed/vmlinux: $(TOPDIR)/vmlinux
 	@$(MAKE) -C compressed vmlinux
 

@@ -75,5 +78,5 @@
 clean:
 	rm -f tools/build
 	rm -f realmode zImage
-	rm -f brealmode bzImage
+	rm -f brealmode bzImage bzElf
 	@$(MAKE) -C compressed clean