source: SVN/rincon/u-boot/board/sc520_cdp/sc520_cdp_asm16.S @ 55

Last change on this file since 55 was 55, checked in by Tim Harvey, 22 months ago

rincon: added latest u-boot source

restored form server backup

Signed-off-by: Tim Harvey <tharvey@…>

File size: 1.9 KB
Line 
1/*
2 * (C) Copyright 2002
3 * Daniel Engström, Omicron Ceti AB <daniel@omicron.se>.
4 *
5 * See file CREDITS for list of people who contributed to this
6 * project.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21 * MA 02111-1307 USA
22 */
23
24/*
25 * 16bit initialization code.
26 * This code have to map the area of the boot flash
27 * that is used by U-boot to its final destination.
28 */
29
30.text
31.section .start16, "ax"
32.code16
33.globl board_init16
34board_init16:
35        /* Alias MMCR to 0xdf000 */
36        movw    $0xfffc, %dx
37        movl    $0x800df0cb, %eax
38        outl    %eax, %dx
39
40        /* Set ds to point to MMCR alias */
41        movw    $0xdf00, %ax
42        movw    %ax, %ds
43
44        /* Map the entire flash at 0x38000000
45         * (with BOOTCS and PAR14, use 0xabfff800 for ROMCS1) */
46        movl    $0xc0, %edi
47        movl    $0x8bfff800, %eax
48        movl    %eax, (%di)
49
50        /* Disable SDRAM write buffer */
51        movw    $0x40,%di
52        xorw    %ax,%ax
53        movb    %al, (%di)
54
55        /* Disabe MMCR alias */
56        movw    $0xfffc, %dx
57        movl    $0x000000cb, %eax
58        outl    %eax, %dx
59
60        /* the return address is tored in bp */
61        jmp     *%bp
62
63
64.section .bios, "ax"
65.code16
66.globl realmode_reset
67realmode_reset:
68        /* Alias MMCR to 0xdf000 */
69        movw    $0xfffc, %dx
70        movl    $0x800df0cb, %eax
71        outl    %eax, %dx
72
73        /* Set ds to point to MMCR alias */
74        movw    $0xdf00, %ax
75        movw    %ax, %ds
76
77        /* issue software reset thorugh MMCR */
78        movl    $0xd72, %edi
79        movb    $0x01, %al
80        movb    %al, (%di)
81
821:      hlt
83        jmp     1
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