mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 20:53:53 +08:00
8b664aa66e
This patch adds a field of 64-bit physical pointer to NULL terminated single linked list of struct setup_data to real-mode kernel header. This is used as a more extensible boot parameters passing mechanism. Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
317 lines
7.8 KiB
ArmAsm
317 lines
7.8 KiB
ArmAsm
/*
|
|
* header.S
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*
|
|
* Based on bootsect.S and setup.S
|
|
* modified by more people than can be counted
|
|
*
|
|
* Rewritten as a common file by H. Peter Anvin (Apr 2007)
|
|
*
|
|
* BIG FAT NOTE: We're in real mode using 64k segments. Therefore segment
|
|
* addresses must be multiplied by 16 to obtain their respective linear
|
|
* addresses. To avoid confusion, linear addresses are written using leading
|
|
* hex while segment addresses are written as segment:offset.
|
|
*
|
|
*/
|
|
|
|
#include <asm/segment.h>
|
|
#include <linux/utsrelease.h>
|
|
#include <asm/boot.h>
|
|
#include <asm/e820.h>
|
|
#include <asm/page.h>
|
|
#include <asm/setup.h>
|
|
#include "boot.h"
|
|
#include "offsets.h"
|
|
|
|
SETUPSECTS = 4 /* default nr of setup-sectors */
|
|
BOOTSEG = 0x07C0 /* original address of boot-sector */
|
|
SYSSEG = DEF_SYSSEG /* system loaded at 0x10000 (65536) */
|
|
SYSSIZE = DEF_SYSSIZE /* system size: # of 16-byte clicks */
|
|
/* to be loaded */
|
|
ROOT_DEV = 0 /* ROOT_DEV is now written by "build" */
|
|
SWAP_DEV = 0 /* SWAP_DEV is now written by "build" */
|
|
|
|
#ifndef SVGA_MODE
|
|
#define SVGA_MODE ASK_VGA
|
|
#endif
|
|
|
|
#ifndef RAMDISK
|
|
#define RAMDISK 0
|
|
#endif
|
|
|
|
#ifndef ROOT_RDONLY
|
|
#define ROOT_RDONLY 1
|
|
#endif
|
|
|
|
.code16
|
|
.section ".bstext", "ax"
|
|
|
|
.global bootsect_start
|
|
bootsect_start:
|
|
|
|
# Normalize the start address
|
|
ljmp $BOOTSEG, $start2
|
|
|
|
start2:
|
|
movw %cs, %ax
|
|
movw %ax, %ds
|
|
movw %ax, %es
|
|
movw %ax, %ss
|
|
xorw %sp, %sp
|
|
sti
|
|
cld
|
|
|
|
movw $bugger_off_msg, %si
|
|
|
|
msg_loop:
|
|
lodsb
|
|
andb %al, %al
|
|
jz bs_die
|
|
movb $0xe, %ah
|
|
movw $7, %bx
|
|
int $0x10
|
|
jmp msg_loop
|
|
|
|
bs_die:
|
|
# Allow the user to press a key, then reboot
|
|
xorw %ax, %ax
|
|
int $0x16
|
|
int $0x19
|
|
|
|
# int 0x19 should never return. In case it does anyway,
|
|
# invoke the BIOS reset code...
|
|
ljmp $0xf000,$0xfff0
|
|
|
|
.section ".bsdata", "a"
|
|
bugger_off_msg:
|
|
.ascii "Direct booting from floppy is no longer supported.\r\n"
|
|
.ascii "Please use a boot loader program instead.\r\n"
|
|
.ascii "\n"
|
|
.ascii "Remove disk and press any key to reboot . . .\r\n"
|
|
.byte 0
|
|
|
|
|
|
# Kernel attributes; used by setup. This is part 1 of the
|
|
# header, from the old boot sector.
|
|
|
|
.section ".header", "a"
|
|
.globl hdr
|
|
hdr:
|
|
setup_sects: .byte SETUPSECTS
|
|
root_flags: .word ROOT_RDONLY
|
|
syssize: .long SYSSIZE
|
|
ram_size: .word RAMDISK
|
|
vid_mode: .word SVGA_MODE
|
|
root_dev: .word ROOT_DEV
|
|
boot_flag: .word 0xAA55
|
|
|
|
# offset 512, entry point
|
|
|
|
.globl _start
|
|
_start:
|
|
# Explicitly enter this as bytes, or the assembler
|
|
# tries to generate a 3-byte jump here, which causes
|
|
# everything else to push off to the wrong offset.
|
|
.byte 0xeb # short (2-byte) jump
|
|
.byte start_of_setup-1f
|
|
1:
|
|
|
|
# Part 2 of the header, from the old setup.S
|
|
|
|
.ascii "HdrS" # header signature
|
|
.word 0x0209 # header version number (>= 0x0105)
|
|
# or else old loadlin-1.5 will fail)
|
|
.globl realmode_swtch
|
|
realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
|
|
start_sys_seg: .word SYSSEG
|
|
.word kernel_version-512 # pointing to kernel version string
|
|
# above section of header is compatible
|
|
# with loadlin-1.5 (header v1.5). Don't
|
|
# change it.
|
|
|
|
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
|
|
#ifndef __BIG_KERNEL__
|
|
.byte 0
|
|
#else
|
|
.byte LOADED_HIGH
|
|
#endif
|
|
|
|
setup_move_size: .word 0x8000 # size to move, when setup is not
|
|
# loaded at 0x90000. We will move setup
|
|
# to 0x90000 then just before jumping
|
|
# into the kernel. However, only the
|
|
# loader knows how much data behind
|
|
# us also needs to be loaded.
|
|
|
|
code32_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
|
|
# address where it loaded the image.
|
|
# This only will be read by the kernel.
|
|
|
|
ramdisk_size: .long 0 # its size in bytes
|
|
|
|
bootsect_kludge:
|
|
.long 0 # obsolete
|
|
|
|
heap_end_ptr: .word _end+STACK_SIZE-512
|
|
# (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 0x7fffffff
|
|
# (Header version 0x0203 or later)
|
|
# The highest safe address for
|
|
# the contents of an initrd
|
|
# The current kernel allows up to 4 GB,
|
|
# but leave it at 2 GB to avoid
|
|
# possible bootloader bugs.
|
|
|
|
kernel_alignment: .long CONFIG_PHYSICAL_ALIGN #physical addr alignment
|
|
#required for protected mode
|
|
#kernel
|
|
#ifdef CONFIG_RELOCATABLE
|
|
relocatable_kernel: .byte 1
|
|
#else
|
|
relocatable_kernel: .byte 0
|
|
#endif
|
|
pad2: .byte 0
|
|
pad3: .word 0
|
|
|
|
cmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line,
|
|
#added with boot protocol
|
|
#version 2.06
|
|
|
|
hardware_subarch: .long 0 # subarchitecture, added with 2.07
|
|
# default to 0 for normal x86 PC
|
|
|
|
hardware_subarch_data: .quad 0
|
|
|
|
payload_offset: .long input_data
|
|
payload_length: .long input_data_end-input_data
|
|
|
|
setup_data: .quad 0 # 64-bit physical pointer to
|
|
# single linked list of
|
|
# struct setup_data
|
|
|
|
# End of setup header #####################################################
|
|
|
|
.section ".inittext", "ax"
|
|
start_of_setup:
|
|
#ifdef SAFE_RESET_DISK_CONTROLLER
|
|
# Reset the disk controller.
|
|
movw $0x0000, %ax # Reset disk controller
|
|
movb $0x80, %dl # All disks
|
|
int $0x13
|
|
#endif
|
|
|
|
# Force %es = %ds
|
|
movw %ds, %ax
|
|
movw %ax, %es
|
|
cld
|
|
|
|
# Apparently some ancient versions of LILO invoked the kernel with %ss != %ds,
|
|
# which happened to work by accident for the old code. Recalculate the stack
|
|
# pointer if %ss is invalid. Otherwise leave it alone, LOADLIN sets up the
|
|
# stack behind its own code, so we can't blindly put it directly past the heap.
|
|
|
|
movw %ss, %dx
|
|
cmpw %ax, %dx # %ds == %ss?
|
|
movw %sp, %dx
|
|
je 2f # -> assume %sp is reasonably set
|
|
|
|
# Invalid %ss, make up a new stack
|
|
movw $_end, %dx
|
|
testb $CAN_USE_HEAP, loadflags
|
|
jz 1f
|
|
movw heap_end_ptr, %dx
|
|
1: addw $STACK_SIZE, %dx
|
|
jnc 2f
|
|
xorw %dx, %dx # Prevent wraparound
|
|
|
|
2: # Now %dx should point to the end of our stack space
|
|
andw $~3, %dx # dword align (might as well...)
|
|
jnz 3f
|
|
movw $0xfffc, %dx # Make sure we're not zero
|
|
3: movw %ax, %ss
|
|
movzwl %dx, %esp # Clear upper half of %esp
|
|
sti # Now we should have a working stack
|
|
|
|
# We will have entered with %cs = %ds+0x20, normalize %cs so
|
|
# it is on par with the other segments.
|
|
pushw %ds
|
|
pushw $6f
|
|
lretw
|
|
6:
|
|
|
|
# Check signature at end of setup
|
|
cmpl $0x5a5aaa55, setup_sig
|
|
jne setup_bad
|
|
|
|
# Zero the bss
|
|
movw $__bss_start, %di
|
|
movw $_end+3, %cx
|
|
xorl %eax, %eax
|
|
subw %di, %cx
|
|
shrw $2, %cx
|
|
rep; stosl
|
|
|
|
# Jump to C code (should not return)
|
|
calll main
|
|
|
|
# Setup corrupt somehow...
|
|
setup_bad:
|
|
movl $setup_corrupt, %eax
|
|
calll puts
|
|
# Fall through...
|
|
|
|
.globl die
|
|
.type die, @function
|
|
die:
|
|
hlt
|
|
jmp die
|
|
|
|
.size die, .-die
|
|
|
|
.section ".initdata", "a"
|
|
setup_corrupt:
|
|
.byte 7
|
|
.string "No setup signature found...\n"
|