grub/grub-core/boot/sparc64/ieee1275/boot.S

263 lines
6.8 KiB
ArmAsm

/* -*-Asm-*- */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* GRUB 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, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/machine/boot.h>
.text
.align 4
/*
* We're writing the a.out header ourselves as newer
* upstream versions of binutils no longer support
* the a.out format on sparc64.
*
* The boot loader fits into 512 bytes with 32 bytes
* used for the a.out header, hence the text segment
* size is 512 - 32. There is no data segment and no
* code relocation, thus those fields remain zero.
*/
.word 0x1030107 /* Magic number. */
.word 512 - GRUB_BOOT_AOUT_HEADER_SIZE /* Size of text segment. */
.word 0 /* Size of initialized data. */
.word 0 /* Size of uninitialized data. */
.word 0 /* Size of symbol table || checksum. */
.word _start /* Entry point. */
.word 0 /* Size of text relocation. */
.word 0 /* Size of data relocation. */
.globl _start
_start:
/* OF CIF entry point arrives in %o4 */
pic_base:
call boot_continue
mov %o4, CIF_REG
#ifndef CDBOOT
/* The offsets to these locations are defined by the
* GRUB_BOOT_MACHINE_foo macros in include/grub/sparc64/ieee1275/boot.h,
* and grub-setup uses this to patch these next three values as needed.
*
* The boot_path will be the OF device path of the partition where the
* rest of the GRUB kernel image resides. kernel_sector will be set to
* the location of the first block of the GRUB kernel, and
* kernel_address is the location where we should load that first block.
*
* After loading in that block we will execute it by jumping to the
* load address plus the size of the prepended A.OUT header (32 bytes).
*
* Since this assembly code includes the 32 bytes long a.out header,
* we need to move the actual code entry point forward by the size
* of the a.out header, i.e. += GRUB_BOOT_AOUT_HEADER_SIZE.
*/
.org GRUB_BOOT_MACHINE_BOOT_DEVPATH + GRUB_BOOT_AOUT_HEADER_SIZE
boot_path:
.org GRUB_BOOT_MACHINE_KERNEL_BYTE + GRUB_BOOT_AOUT_HEADER_SIZE
boot_path_end:
kernel_byte: .xword (2 << 9)
kernel_address: .word GRUB_BOOT_MACHINE_KERNEL_ADDR
#else
#define boot_path (_start + 512 + SCRATCH_PAD_BOOT_SIZE)
#define boot_path_end (_start + 1024)
#include <grub/offsets.h>
.org 8 + GRUB_BOOT_AOUT_HEADER_SIZE
kernel_byte: .xword (2 << 9)
kernel_size: .word 512
kernel_address: .word GRUB_BOOT_SPARC64_IEEE1275_IMAGE_ADDRESS
#endif
prom_finddev_name: .asciz "finddevice"
prom_chosen_path: .asciz "/chosen"
prom_getprop_name: .asciz "getprop"
prom_stdout_name: .asciz "stdout"
prom_write_name: .asciz "write"
prom_bootpath_name: .asciz "bootpath"
prom_open_name: .asciz "open"
prom_seek_name: .asciz "seek"
prom_read_name: .asciz "read"
prom_exit_name: .asciz "exit"
grub_name: .asciz "GRUB "
#ifdef CDBOOT
prom_close_name: .asciz "close"
#endif
#define GRUB_NAME_LEN 5
.align 4
prom_open_error:
GET_ABS(prom_open_name, %o2)
call console_write
mov 4, %o3
/* fallthru */
prom_error:
GET_ABS(prom_exit_name, %o0)
/* fallthru */
/* %o0: OF call name
* %o1: input arg 1
*/
prom_call_1_1_o2:
clr %o2
ba prom_call_x_1
mov 1, %g1
prom_call_getprop:
mov 4, %g1
stx %g1, [%l1 + 256]
mov CHOSEN_NODE_REG, %o1
ba prom_call_x_1
GET_ABS(prom_getprop_name, %o0)
prom_call_3_1_o1:
ba prom_call_3_1
mov BOOTDEV_REG, %o1
/* %o2: message string
* %o3: message length
*/
console_write:
GET_ABS(prom_write_name, %o0)
mov STDOUT_NODE_REG, %o1
/* fallthru */
/* %o0: OF call name
* %o1: input arg 1
* %o2: input arg 2
* %o3: input arg 3
*/
prom_call_3_1:
mov 3, %g1
prom_call_x_1:
mov 1, %o5
/* fallthru */
/* %o0: OF call name
* %g1: num inputs
* %o5: num outputs
* %o1-%o4: inputs
*/
prom_call:
stx %o0, [%l1 + 0x00]
stx %g1, [%l1 + 0x08]
stx %o5, [%l1 + 0x10]
stx %o1, [%l1 + 0x18]
stx %o2, [%l1 + 0x20]
stx %o3, [%l1 + 0x28]
stx %o4, [%l1 + 0x30]
jmpl CIF_REG, %g0
mov %l1, %o0
boot_continue:
mov %o7, PIC_REG /* PIC base */
#ifndef CDBOOT
sethi %hi(SCRATCH_PAD_BOOT), %l1 /* OF argument slots */
#else
GET_ABS(_start + 512, %l1) /* OF argument slots */
#endif
/* Find the /chosen node so we can fetch the stdout handle,
* and thus perform console output.
*
* chosen_node = prom_finddevice("/chosen")
*/
GET_ABS(prom_finddev_name, %o0)
call prom_call_1_1_o2
GET_ABS(prom_chosen_path, %o1)
ldx [%l1 + 0x20], CHOSEN_NODE_REG
brz CHOSEN_NODE_REG, prom_error
/* getprop(chosen_node, "stdout", &buffer, buffer_size) */
GET_ABS(prom_stdout_name, %o2)
add %l1, 256, %o3
call prom_call_getprop
mov 1024, %o4
lduw [%l1 + 256], STDOUT_NODE_REG
brz,pn STDOUT_NODE_REG, prom_error
/* write(stdout_node, "GRUB ", strlen("GRUB ")) */
GET_ABS(grub_name, %o2)
call console_write
mov GRUB_NAME_LEN, %o3
GET_ABS(boot_path, %o3)
#ifndef CDBOOT
ldub [%o3], %o1
brnz,pn %o1, bootpath_known
#endif
/* getprop(chosen_node, "bootpath", &buffer, buffer_size) */
GET_ABS(prom_bootpath_name, %o2)
call prom_call_getprop
mov (boot_path_end - boot_path), %o4
bootpath_known:
/* Open up the boot_path, and use that handle to read the
* first block of the GRUB kernel image.
*
* bootdev_handle = open(boot_path)
*/
GET_ABS(prom_open_name, %o0)
call prom_call_1_1_o2
GET_ABS(boot_path, %o1)
ldx [%l1 + 0x20], BOOTDEV_REG
brz,pn BOOTDEV_REG, prom_open_error
/* Since we have 64-bit cells, the high cell of the seek offset
* is zero and the low cell is the entire value.
*
* seek(bootdev, 0, *kernel_byte)
*/
GET_ABS(prom_seek_name, %o0)
clr %o2
call prom_call_3_1_o1
LDX_ABS(kernel_byte, 0x00, %o3)
/* read(bootdev, *kernel_address, 512) */
GET_ABS(prom_read_name, %o0)
LDUW_ABS(kernel_address, 0x00, %o2)
call prom_call_3_1_o1
#ifdef CDBOOT
LDUW_ABS(kernel_size, 0x00, %o3)
GET_ABS(prom_close_name, %o0)
mov 1, %g1
mov 0, %o5
call prom_call
mov BOOTDEV_REG, %o1
#else
mov 512, %o3
#endif
LDUW_ABS(kernel_address, 0x00, %o2)
jmpl %o2, %o7
#ifdef CDBOOT
mov CIF_REG, %o4
#else
nop
#endif
.org GRUB_BOOT_MACHINE_CODE_END
/* the last 4 bytes in the sector 0 contain the signature */
.word GRUB_BOOT_MACHINE_SIGNATURE