| /* |
| * (C) Copyright 2007 Michal Simek |
| * (C) Copyright 2004 Atmark Techno, Inc. |
| * |
| * Michal SIMEK <monstr@monstr.eu> |
| * Yasushi SHOJI <yashi@atmark-techno.com> |
| * |
| * 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> |
| |
| .text |
| .global _start |
| _start: |
| mts rmsr, r0 /* disable cache */ |
| addi r1, r0, CFG_INIT_SP_OFFSET |
| addi r1, r1, -4 /* Decrement SP to top of memory */ |
| /* add opcode instruction for 32bit jump - 2 instruction imm & brai*/ |
| addi r6, r0, 0xb000 /* hex b000 opcode imm */ |
| bslli r6, r6, 16 /* shift */ |
| swi r6, r0, 0x0 /* reset address */ |
| swi r6, r0, 0x8 /* user vector exception */ |
| swi r6, r0, 0x10 /* interrupt */ |
| swi r6, r0, 0x20 /* hardware exception */ |
| |
| addi r6, r0, 0xb808 /* hew b808 opcode brai*/ |
| bslli r6, r6, 16 |
| swi r6, r0, 0x4 /* reset address */ |
| swi r6, r0, 0xC /* user vector exception */ |
| swi r6, r0, 0x14 /* interrupt */ |
| swi r6, r0, 0x24 /* hardware exception */ |
| |
| #ifdef CFG_RESET_ADDRESS |
| /* reset address */ |
| addik r6, r0, CFG_RESET_ADDRESS |
| sw r6, r1, r0 |
| lhu r7, r1, r0 |
| shi r7, r0, 0x2 |
| shi r6, r0, 0x6 |
| /* |
| * Copy U-Boot code to TEXT_BASE |
| * solve problem with sbrk_base |
| */ |
| #if (CFG_RESET_ADDRESS != TEXT_BASE) |
| addi r4, r0, __end |
| addi r5, r0, __text_start |
| rsub r4, r5, r4 /* size = __end - __text_start */ |
| addi r6, r0, CFG_RESET_ADDRESS /* source address */ |
| addi r7, r0, 0 /* counter */ |
| 4: |
| lw r8, r6, r7 |
| sw r8, r5, r7 |
| addi r7, r7, 0x4 |
| cmp r8, r4, r7 |
| blti r8, 4b |
| #endif |
| #endif |
| |
| #ifdef CFG_USR_EXCEP |
| /* user_vector_exception */ |
| addik r6, r0, _exception_handler |
| sw r6, r1, r0 |
| lhu r7, r1, r0 |
| shi r7, r0, 0xa |
| shi r6, r0, 0xe |
| #endif |
| |
| #ifdef CFG_INTC_0 |
| /* interrupt_handler */ |
| addik r6, r0, _interrupt_handler |
| sw r6, r1, r0 |
| lhu r7, r1, r0 |
| shi r7, r0, 0x12 |
| shi r6, r0, 0x16 |
| #endif |
| |
| /* hardware exception */ |
| addik r6, r0, _hw_exception_handler |
| sw r6, r1, r0 |
| lhu r7, r1, r0 |
| shi r7, r0, 0x22 |
| shi r6, r0, 0x26 |
| |
| /* enable instruction and data cache */ |
| mfs r12, rmsr |
| ori r12, r12, 0xa0 |
| mts rmsr, r12 |
| |
| clear_bss: |
| /* clear BSS segments */ |
| addi r5, r0, __bss_start |
| addi r4, r0, __bss_end |
| cmp r6, r5, r4 |
| beqi r6, 3f |
| 2: |
| swi r0, r5, 0 /* write zero to loc */ |
| addi r5, r5, 4 /* increment to next loc */ |
| cmp r6, r5, r4 /* check if we have reach the end */ |
| bnei r6, 2b |
| 3: /* jumping to board_init */ |
| brai board_init |
| 1: bri 1b |