* Patch by Daniel Engström, 13 Nov 2002:
Add support for i386 architecture and AMD SC520 board
* Patch by Pierre Aubert, 12 Nov 2002:
Add support for DOS filesystem and booting from DOS floppy disk
diff --git a/cpu/i386/start.S b/cpu/i386/start.S
new file mode 100644
index 0000000..025555c
--- /dev/null
+++ b/cpu/i386/start.S
@@ -0,0 +1,198 @@
+/*
+ * 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
+.progress0:
+
+ /* size memory */
+ mov $mem_init_ret, %ebp
+ jmp mem_init
+mem_init_ret:
+
+ /* check ammount of configured memory
+ * (we need atleast bss start+bss size+stack size) */
+ movl $_i386boot_bss_start, %ecx /* BSS start */
+ addl $_i386boot_bss_size, %ecx /* BSS size */
+ addl $CFG_STACK_SIZE, %ecx
+ cmpl %ecx, %eax
+ jae mem_ok
+
+ /* indicate (lack of) progress */
+ movw $0x81, %ax
+ movl $.progress0a, %ebp
+ jmp __show_boot_progress
+.progress0a:
+ jmp die
+mem_ok:
+
+ /* indicate progress */
+ movw $0x02, %ax
+ movl $.progress1, %ebp
+ jmp __show_boot_progress
+.progress1:
+
+ /* create a stack after the bss */
+ movl $_i386boot_bss_start, %eax
+ addl $_i386boot_bss_size, %eax
+ addl $CFG_STACK_SIZE, %eax
+ movl %eax, %esp
+
+ 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
+.progress1a:
+ jmp die
+
+
+stack_ok:
+ /* indicate progress */
+ movw $0x03, %ax
+ movl $.progress2, %ebp
+ jmp __show_boot_progress
+.progress2:
+
+ /* copy data section to ram, size must be 4-byte aligned */
+ movl $_i386boot_romdata_dest, %edi /* destination address */
+ movl $_i386boot_romdata_start, %esi /* source address */
+ movl $_i386boot_romdata_size, %ecx /* number of bytes to copy */
+ movl %ecx, %eax
+ andl $3, %eax
+ jnz data_fail
+
+ shrl $2, %ecx /* copy 4 byte each time */
+ cld
+ cmpl $0, %ecx
+ je data_ok
+data_segment:
+ movsl
+ loop data_segment
+ jmp data_ok
+data_fail:
+ /* indicate (lack of) progress */
+ movw $0x83, %ax
+ movl $.progress2a, %ebp
+ jmp __show_boot_progress
+.progress2a:
+ jmp die
+
+data_ok:
+
+ /* indicate progress */
+ movw $0x04, %ax
+ movl $.progress3, %ebp
+ jmp __show_boot_progress
+.progress3:
+
+ /* clear bss section in ram, size must be 4-byte aligned */
+ movl $_i386boot_bss_start, %eax /* BSS start */
+ movl $_i386boot_bss_size, %ecx /* BSS size */
+ movl %ecx, %eax
+ andl $3, %eax
+ jnz bss_fail
+ shrl $2, %ecx /* clear 4 byte each time */
+ cld
+ cmpl $0, %ecx
+ je bss_ok
+bss:
+ movl $0, (%edi)
+ add $4, %edi
+ loop bss
+ jmp bss_ok
+
+bss_fail:
+ /* indicate (lack of) progress */
+ movw $0x84, %ax
+ movl $.progress3a, %ebp
+ jmp __show_boot_progress
+.progress3a:
+ jmp die
+
+bss_ok:
+
+ wbinvd
+
+
+ /* indicate progress */
+ movw $0x05, %ax
+ movl $.progress4, %ebp
+ jmp __show_boot_progress
+.progress4:
+
+ call start_i386boot /* Enter, U-boot! */
+
+ /* indicate (lack of) progress */
+ movw $0x85, %ax
+ movl $.progress4a, %ebp
+ jmp __show_boot_progress
+.progress4a:
+
+die: hlt
+ jmp die
+ hlt
+
+