124 lines
3.2 KiB
ArmAsm
124 lines
3.2 KiB
ArmAsm
/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 1999,2000,2001,2002,2003,2005,2006,2007,2008 Free Software Foundation, Inc.
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*
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* Note: These functions defined in this file may be called from C.
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* Be careful of that you must not modify some registers. Quote
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* from gcc-2.95.2/gcc/config/i386/i386.h:
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1 for registers not available across function calls.
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These must include the FIXED_REGISTERS and also any
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registers that can be used without being saved.
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The latter must include the registers where values are returned
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and the register where structure-value addresses are passed.
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Aside from that, you can include as many other registers as you like.
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ax,dx,cx,bx,si,di,bp,sp,st,st1,st2,st3,st4,st5,st6,st7,arg
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{ 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 }
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*/
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/*
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* Note: GRUB is compiled with the options -mrtd and -mregparm=3.
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* So the first three arguments are passed in %eax, %edx, and %ecx,
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* respectively, and if a function has a fixed number of arguments
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* and the number if greater than three, the function must return
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* with "ret $N" where N is ((the number of arguments) - 3) * 4.
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*/
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/*
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* This is the area for all of the special variables.
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*/
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#include <grub/i386/floppy.h>
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.p2align 2 /* force 4-byte alignment */
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/*
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* void grub_linux_boot_zimage (void)
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*/
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VARIABLE(grub_linux_prot_size)
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.long 0
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VARIABLE(grub_linux_tmp_addr)
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.long 0
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VARIABLE(grub_linux_real_addr)
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.long 0
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VARIABLE(grub_linux_is_bzimage)
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.long 0
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FUNCTION(grub_linux16_real_boot)
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/* Must be done before zImage copy. */
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call EXT_C(grub_dl_unload_all)
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movl EXT_C(grub_linux_is_bzimage), %ebx
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test %ebx, %ebx
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jne bzimage
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/* copy the kernel */
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movl EXT_C(grub_linux_prot_size), %ecx
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addl $3, %ecx
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shrl $2, %ecx
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movl $GRUB_LINUX_BZIMAGE_ADDR, %esi
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movl $GRUB_LINUX_ZIMAGE_ADDR, %edi
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cld
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rep
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movsl
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bzimage:
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movl EXT_C(grub_linux_real_addr), %ebx
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/* copy the real mode code */
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movl EXT_C(grub_linux_tmp_addr), %esi
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movl %ebx, %edi
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movl $GRUB_LINUX_SETUP_MOVE_SIZE, %ecx
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cld
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rep
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movsb
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/* change %ebx to the segment address */
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shrl $4, %ebx
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movl %ebx, %eax
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addl $0x20, %eax
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movw %ax, linux_setup_seg
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/* XXX new stack pointer in safe area for calling functions */
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movl $0x4000, %esp
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movw $GRUB_FLOPPY_REG_DIGITAL_OUTPUT, %dx
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xorb %al, %al
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outb %al, %dx
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/* final setup for linux boot */
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call prot_to_real
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.code16
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cli
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movw %bx, %ss
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movw $GRUB_LINUX_SETUP_STACK, %sp
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movw %bx, %ds
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movw %bx, %es
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movw %bx, %fs
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movw %bx, %gs
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/* ljmp */
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.byte 0xea
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.word 0
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linux_setup_seg:
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.word 0
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.code32
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