| Graeme Russ | c620c01 | 2008-12-07 10:28:57 +1100 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright 2008 |
| 3 | * Graeme Russ, graeme.russ@gmail.com. |
| 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 | /* #include <asm/ic/sc520_defs.h> */ |
| 31 | |
| 32 | #include "hardware.h" |
| 33 | |
| 34 | .text |
| 35 | .section .start16, "ax" |
| 36 | .code16 |
| 37 | .globl board_init16 |
| 38 | board_init16: |
| 39 | /* Alias MMCR to 0xdf000 */ |
| 40 | movw $0xfffc, %dx |
| 41 | movl $0x800df0cb, %eax |
| 42 | outl %eax, %dx |
| 43 | |
| 44 | /* Set ds to point to MMCR alias */ |
| 45 | movw $0xdf00, %ax |
| 46 | movw %ax, %ds |
| 47 | |
| 48 | /* Map PAR for Boot Flash (BOOTCS, 512kB @ 0x380000000) */ |
| 49 | movl $0x00c0, %edi /* SC520_PAR14 */ |
| 50 | movl $0x8bfff800, %eax /* TODO: Check this */ |
| 51 | movl %eax, (%di) |
| 52 | |
| 53 | /* Map PAR for LED, Hex Switches (GPCS6, 20 Bytes @ 0x1000) */ |
| 54 | movl $0x00c4, %edi /* SC520_PAR15 */ |
| 55 | movl $0x38201000, %eax |
| 56 | movl %eax, (%di) |
| 57 | |
| 58 | /* Disable SDRAM write buffer */ |
| 59 | movw $0x0040, %di /* SC520_DBCTL */ |
| 60 | xorw %ax, %ax |
| 61 | movb %al, (%di) |
| 62 | |
| 63 | /* Disabe MMCR alias */ |
| 64 | movw $0xfffc, %dx |
| 65 | movl $0x000000cb, %eax |
| 66 | outl %eax, %dx |
| 67 | |
| 68 | /* the return address is stored in bp */ |
| 69 | jmp *%bp |
| 70 | |
| 71 | .section .bios, "ax" |
| 72 | .code16 |
| 73 | .globl realmode_reset |
| 74 | realmode_reset: |
| 75 | /* Alias MMCR to 0xdf000 */ |
| 76 | movw $0xfffc, %dx |
| 77 | movl $0x800df0cb, %eax |
| 78 | outl %eax, %dx |
| 79 | |
| 80 | /* Set ds to point to MMCR alias */ |
| 81 | movw $0xdf00, %ax |
| 82 | movw %ax, %ds |
| 83 | |
| 84 | /* issue software reset thorugh MMCR */ |
| 85 | movl $0xd72, %edi |
| 86 | movb $0x01, %al |
| 87 | movb %al, (%di) |
| 88 | |
| 89 | 1: hlt |
| 90 | jmp 1 |