2 * (C) Copyright 2007 Michal Simek
3 * (C) Copyright 2004 Atmark Techno, Inc.
5 * Michal SIMEK <monstr@monstr.eu>
6 * Yasushi SHOJI <yashi@atmark-techno.com>
8 * See file CREDITS for list of people who contributed to this
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation; either version 2 of
14 * the License, or (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 #include <asm-offsets.h>
35 * r10: Stores little/big endian offset for vectors
36 * r2: Stores imm opcode
37 * r3: Stores brai opcode
40 mts rmsr, r0 /* disable cache */
41 addi r1, r0, CONFIG_SYS_INIT_SP_OFFSET
42 addi r1, r1, -4 /* Decrement SP to top of memory */
44 /* Find-out if u-boot is running on BIG/LITTLE endian platform
45 * There are some steps which is necessary to keep in mind:
46 * 1. Setup offset value to r6
47 * 2. Store word offset value to address 0x0
48 * 3. Load just byte from address 0x0
49 * 4a) LITTLE endian - r10 contains 0x2 because it is the smallest
50 * value that's why is on address 0x0
51 * 4b) BIG endian - r10 contains 0x0 because 0x2 offset is on addr 0x3
53 addik r6, r0, 0x2 /* BIG/LITTLE endian offset */
55 swi r6, r0, 0x28 /* used first unused MB vector */
56 lbui r10, r0, 0x28 /* used first unused MB vector */
59 /* add opcode instruction for 32bit jump - 2 instruction imm & brai */
60 addi r2, r0, 0xb0000000 /* hex b000 opcode imm */
61 addi r3, r0, 0xb8080000 /* hew b808 opcode brai */
63 #ifdef CONFIG_SYS_RESET_ADDRESS
65 swi r2, r0, 0x0 /* reset address - imm opcode */
66 swi r3, r0, 0x4 /* reset address - brai opcode */
68 addik r6, r0, CONFIG_SYS_RESET_ADDRESS
74 * Copy U-Boot code to CONFIG_SYS_TEXT_BASE
75 * solve problem with sbrk_base
77 #if (CONFIG_SYS_RESET_ADDRESS != CONFIG_SYS_TEXT_BASE)
79 addi r5, r0, __text_start
80 rsub r4, r5, r4 /* size = __end - __text_start */
81 addi r6, r0, CONFIG_SYS_RESET_ADDRESS /* source address */
82 addi r7, r0, 0 /* counter */
92 #ifdef CONFIG_SYS_USR_EXCEP
93 /* user_vector_exception */
94 swi r2, r0, 0x8 /* user vector exception - imm opcode */
95 swi r3, r0, 0xC /* user vector exception - brai opcode */
97 addik r6, r0, _exception_handler
100 * BIG ENDIAN memory map for user exception
104 * then it is necessary to count address for storing the most significant
105 * 16bits from _exception_handler address and copy it to
106 * 0xa address. Big endian use offset in r10=0 that's why is it just
107 * 0xa address. The same is done for the least significant 16 bits
110 * LITTLE ENDIAN memory map for user exception
114 * Offset is for little endian setup to 0x2. rsubi instruction decrease
115 * address value to ensure that points to proper place which is
116 * 0x8 for the most significant 16 bits and
117 * 0xC for the least significant 16 bits
126 #ifdef CONFIG_SYS_INTC_0
127 /* interrupt_handler */
128 swi r2, r0, 0x10 /* interrupt - imm opcode */
129 swi r3, r0, 0x14 /* interrupt - brai opcode */
131 addik r6, r0, _interrupt_handler
140 /* hardware exception */
141 swi r2, r0, 0x20 /* hardware exception - imm opcode */
142 swi r3, r0, 0x24 /* hardware exception - brai opcode */
144 addik r6, r0, _hw_exception_handler
152 /* enable instruction and data cache */
158 /* clear BSS segments */
159 addi r5, r0, __bss_start
160 addi r4, r0, __bss_end
164 swi r0, r5, 0 /* write zero to loc */
165 addi r5, r5, 4 /* increment to next loc */
166 cmp r6, r5, r4 /* check if we have reach the end */
168 3: /* jumping to board_init */
173 * Read 16bit little endian
189 * Write 16bit little endian
190 * first parameter(r5) - address, second(r6) - short value
196 out16: bslli r3, r6, 8