gumstix_start.S revision 1.2
1 /* $NetBSD: gumstix_start.S,v 1.2 2007/02/20 17:50:43 kiyohara Exp $ */ 2 /* 3 * Copyright (C) 2005, 2006 WIDE Project and SOUM Corporation. 4 * All rights reserved. 5 * 6 * Written by Takashi Kiyohara and Susumu Miki for WIDE Project and SOUM 7 * Corporation. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the name of SOUM Corporation 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT and SOUM CORPORATION ``AS IS'' 22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT AND SOUM CORPORATION 25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 * POSSIBILITY OF SUCH DAMAGE. 32 */ 33 /* 34 * Copyright (c) 2002, 2003 Genetec Corporation. All rights reserved. 35 * Written by Hiroyuki Bessho for Genetec Corporation. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. The name of Genetec Corporation may not be used to endorse or 46 * promote products derived from this software without specific prior 47 * written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY GENETEC CORPORATION ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 51 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 52 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GENETEC CORPORATION 53 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 54 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 55 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 56 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 57 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 58 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 59 * POSSIBILITY OF SUCH DAMAGE. 60 */ 61 62 #include <machine/asm.h> 63 #include <arm/armreg.h> 64 #include <arm/arm32/pte.h> 65 #include <arm/arm32/pmap.h> /* for PMAP_DOMAIN_KERNEL */ 66 67 #ifndef SDRAM_START 68 #define SDRAM_START 0xa0000000 69 #endif 70 71 /* 72 * CPWAIT -- Canonical method to wait for CP15 update. 73 * NOTE: Clobbers the specified temp reg. 74 * copied from arm/arm/cpufunc_asm_xscale.S 75 * XXX: better be in a common header file. 76 */ 77 #define CPWAIT_BRANCH \ 78 sub pc, pc, #4 79 80 #define CPWAIT(tmp) \ 81 mrc p15, 0, tmp, c2, c0, 0 /* arbitrary read of CP15 */ ;\ 82 mov tmp, tmp /* wait for it to complete */ ;\ 83 CPWAIT_BRANCH /* branch to next insn */ 84 85 /* 86 * Kernel start routine for GUMSTIX 87 * this code is excuted at the very first after the kernel is loaded 88 * by U-Boot. 89 */ 90 .text 91 92 .global _C_LABEL(gumstix_start) 93 _C_LABEL(gumstix_start): 94 /* gumstix's loader is u-boot. it's running on RAM */ 95 /* 96 * Kernel is loaded in SDRAM (0xa0200000..), and is expected to run 97 * in VA 0xc0200000.. 98 */ 99 /* save u-boot's args */ 100 adr r0, u_boot_args 101 nop 102 nop 103 nop 104 stmia r0!, {r3, r4, r5, r6} 105 nop 106 nop 107 nop 108 109 /* build page table from scratch */ 110 ldr r0, Lstartup_pagetable /* pagetable */ 111 adr r4, mmu_init_table 112 b 3f 113 114 2: 115 str r3, [r0, r2] 116 add r2, r2, #4 117 add r3, r3, #(L1_S_SIZE) 118 adds r1, r1, #-1 119 bhi 2b 120 3: 121 ldmia r4!, {r1,r2,r3} /* # of sections, PA|attr, VA */ 122 cmp r1, #0 123 bne 2b 124 125 mcr p15, 0, r0, c2, c0, 0 /* Set TTB */ 126 mcr p15, 0, r0, c8, c7, 0 /* Flush TLB */ 127 128 /* Set the Domain Access register. Very important! */ 129 mov r0, #((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT) 130 mcr p15, 0, r0, c3, c0, 0 131 132 /* Enable MMU */ 133 mrc p15, 0, r0, c1, c0, 0 134 orr r0, r0, #CPU_CONTROL_SYST_ENABLE 135 orr r0, r0, #CPU_CONTROL_MMU_ENABLE 136 mcr p15, 0, r0, c1, c0, 0 137 CPWAIT(r0) 138 139 /* Jump to kernel code in TRUE VA */ 140 adr r0, Lstart 141 ldr pc, [r0] 142 143 Lstart: 144 .word start 145 146 #ifndef STARTUP_PAGETABLE_ADDR 147 #define STARTUP_PAGETABLE_ADDR 0xa0000000 /* aligned 16kByte */ 148 #endif 149 Lstartup_pagetable: 150 .word STARTUP_PAGETABLE_ADDR 151 152 .globl _C_LABEL(u_boot_args) 153 u_boot_args: 154 .space 16 /* r3, r4, r5, r6 */ 155 156 157 #define MMU_INIT(va,pa,n_sec,attr) \ 158 .word n_sec ; \ 159 .word 4*((va)>>L1_S_SHIFT) ; \ 160 .word (pa)|(attr) ; 161 mmu_init_table: 162 /* fill all table VA==PA */ 163 MMU_INIT(0x00000000, 0x00000000, 164 1<<(32-L1_S_SHIFT), L1_TYPE_S|L1_S_AP(AP_KRW)) 165 /* map SDRAM VA==PA, WT cacheable */ 166 MMU_INIT(SDRAM_START, SDRAM_START, 64, L1_TYPE_S|L1_S_C|L1_S_AP(AP_KRW)) 167 /* map VA 0xc0000000..0xc3ffffff to PA 0xa0000000..0xa3ffffff */ 168 MMU_INIT(0xc0000000, SDRAM_START, 64, L1_TYPE_S|L1_S_C|L1_S_AP(AP_KRW)) 169 170 .word 0 /* end of table */ 171
Indexes created Fri Oct 03 02:09:57 GMT 2025