2 * U-boot - i386 Startup Code
4 * Copyright (c) 2002 Omicron Ceti AB, Daniel Engstr�m <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>
34 .type _start, @function
35 .globl _i386boot_start
38 * This is the fail safe 32-bit bootstrap entry point. The
39 * following code is not executed from a cold-reset (actually, a
40 * lot of it is, but from real-mode after cold reset. It is
41 * repeated here to put the board into a state as close to cold
47 /* Turn of cache (this might require a 486-class CPU) */
53 /* Tell 32-bit code it is being entered from an in-RAM copy */
54 movw $GD_FLG_WARM_BOOT, %bx
56 /* This is the 32-bit cold-reset entry point */
58 movl $0x18, %eax /* Load our segement registes, the
59 * gdt have already been loaded by start16.S */
66 /* Clear the interupt vectors */
69 /* Skip low-level initialization if not starting from cold-reset */
71 andl $GD_FLG_COLD_BOOT, %ecx
74 /* Early platform init (setup gpio, etc ) */
76 .globl early_board_init_ret
85 /* fetch memory size (into %eax) */
87 .globl get_mem_size_ret
90 #if CONFIG_SYS_SDRAM_ECC_ENABLE
91 /* Skip ECC initialization if not starting from cold-reset */
93 andl $GD_FLG_COLD_BOOT, %ecx
101 /* Check we have enough memory for stack */
102 movl $CONFIG_SYS_STACK_SIZE, %ecx
106 /* Set stack pointer to upper memory limit*/
116 cmpl $0x55aa55aa, %ecx
121 /* Set the upper memory limit parameter */
122 subl $CONFIG_SYS_STACK_SIZE, %eax
124 /* Reserve space for global data */
125 subl $(GD_SIZE * 4), %eax
127 /* %eax points to the global data structure */
128 movl %esp, (GD_RAM_SIZE * 4)(%eax)
129 movl %ebx, (GD_FLAGS * 4)(%eax)
131 call board_init_f /* Enter, U-boot! */
133 /* indicate (lack of) progress */