2 * U-boot - i386 Startup Code
4 * Copyright (c) 2002 Omicron Ceti AB, Daniel Engström <denaiel@omicron.se>
6 * See file CREDITS for list of people who contributed to this
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
28 #include <asm/global_data.h>
29 #include <asm/processor-flags.h>
35 .type _start, @function
36 .globl _i386boot_start
39 * This is the fail safe 32-bit bootstrap entry point. The
40 * following code is not executed from a cold-reset (actually, a
41 * lot of it is, but from real-mode after cold reset. It is
42 * repeated here to put the board into a state as close to cold
48 /* Turn of cache (this might require a 486-class CPU) */
50 orl $(X86_CR0_NW | X86_CR0_CD), %eax
54 /* Tell 32-bit code it is being entered from an in-RAM copy */
55 movw $GD_FLG_WARM_BOOT, %bx
57 /* This is the 32-bit cold-reset entry point */
59 movl $0x18, %eax /* Load our segement registes, the
60 * gdt have already been loaded by start16.S */
67 /* Clear the interupt vectors */
70 /* Early platform init (setup gpio, etc ) */
72 .globl early_board_init_ret
75 /* Initialise Cache-As-RAM */
80 * We now have CONFIG_SYS_CAR_SIZE bytes of Cache-As-RAM (or SRAM,
81 * or fully initialised SDRAM - we really don't care which)
82 * starting at CONFIG_SYS_CAR_ADDR to be used as a temporary stack
84 movl $CONFIG_SYS_INIT_SP_ADDR, %esp
85 movl $CONFIG_SYS_INIT_GD_ADDR, %ebp
87 /* Set Boot Flags in Global Data */
88 movl %ebx, (GD_FLAGS * 4)(%ebp)
90 /* Determine our load offset (and put in Global Data) */
94 movl %ecx, (GD_LOAD_OFF * 4)(%ebp)
96 /* Set parameter to board_init_f() to boot flags */
97 movl (GD_FLAGS * 4)(%ebp), %eax
99 call board_init_f /* Enter, U-boot! */
101 /* indicate (lack of) progress */
106 .type relocate_code, @function
109 * SDRAM has been initialised, U-Boot code has been copied into
110 * RAM, BSS has been cleared and relocation adjustments have been
111 * made. It is now time to jump into the in-RAM copy of U-Boot
113 * %eax = Address of top of stack
114 * %edx = Address of Global Data
115 * %ecx = Base address of in-RAM copy of U-Boot
118 /* Setup stack in RAM */
121 /* Setup call address of in-RAM copy of board_init_r() */
122 movl $board_init_r, %ebp
123 addl (GD_RELOC_OFF * 4)(%edx), %ebp
125 /* Setup parameters to board_init_r() */
129 /* Jump to in-RAM copy of board_init_r() */