diff options
Diffstat (limited to 'arch/i386/cpu/start.S')
| -rw-r--r-- | arch/i386/cpu/start.S | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/i386/cpu/start.S b/arch/i386/cpu/start.S new file mode 100644 index 0000000..25d32e6 --- /dev/null +++ b/arch/i386/cpu/start.S @@ -0,0 +1,135 @@ +/* + * U-boot - i386 Startup Code + * + * Copyright (c) 2002 Omicron Ceti AB, Daniel Engström <denaiel@omicron.se> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program 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 2 of + * the License, or (at your option) any later version. + * + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + + +#include <config.h> +#include <version.h> + + +.section .text +.code32 +.globl _start +.type _start, @function +.globl _i386boot_start +_i386boot_start: +_start: + movl $0x18,%eax /* Load our segement registes, the + * gdt have already been loaded by start16.S */ + movw %ax,%fs + movw %ax,%ds + movw %ax,%gs + movw %ax,%es + movw %ax,%ss + + /* We call a few functions in the board support package + * since we have no stack yet we'll have to use %ebp + * to store the return address */ + + /* Early platform init (setup gpio, etc ) */ + mov $early_board_init_ret, %ebp + jmp early_board_init +early_board_init_ret: + + /* The __port80 entry-point should be usabe by now */ + /* so we try to indicate progress */ + movw $0x01, %ax + movl $.progress0, %ebp + jmp show_boot_progress_asm +.progress0: + + /* size memory */ + mov $mem_init_ret, %ebp + jmp mem_init +mem_init_ret: + + /* Check we have enough memory for stack */ + movl $CONFIG_SYS_STACK_SIZE, %ecx + cmpl %ecx, %eax + jae mem_ok + + /* indicate (lack of) progress */ + movw $0x81, %ax + movl $.progress0a, %ebp + jmp show_boot_progress_asm +.progress0a: + jmp die +mem_ok: + /* Set stack pointer to upper memory limit*/ + movl %eax, %esp + + /* indicate progress */ + movw $0x02, %ax + movl $.progress1, %ebp + jmp show_boot_progress_asm +.progress1: + + /* Test the stack */ + pushl $0 + popl %eax + cmpl $0, %eax + jne no_stack + push $0x55aa55aa + popl %ebx + cmpl $0x55aa55aa, %ebx + je stack_ok + +no_stack: + /* indicate (lack of) progress */ + movw $0x82, %ax + movl $.progress1a, %ebp + jmp show_boot_progress_asm +.progress1a: + jmp die + + +stack_ok: + /* indicate progress */ + movw $0x03, %ax + movl $.progress2, %ebp + jmp show_boot_progress_asm +.progress2: + + wbinvd + + /* Get upper memory limit */ + movl %esp, %ecx + subl $CONFIG_SYS_STACK_SIZE, %ecx + + /* Create a Stack Frame */ + pushl %ebp + movl %esp, %ebp + + /* stack_limit parameter */ + pushl %ecx + call board_init_f /* Enter, U-boot! */ + + /* indicate (lack of) progress */ + movw $0x85, %ax + movl $.progress4a, %ebp + jmp show_boot_progress_asm +.progress4a: + +die: hlt + jmp die + hlt |