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- /*
- * (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
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