srtbegin.S revision 1.4.2.3
1 1.4.2.3 nathanw /* $NetBSD: srtbegin.S,v 1.4.2.3 2002/10/18 02:36:35 nathanw Exp $ */ 2 1.4.2.2 nathanw 3 1.4.2.2 nathanw /* 4 1.4.2.2 nathanw * Copyright (c) 2002 Wasabi Systems, Inc. 5 1.4.2.2 nathanw * All rights reserved. 6 1.4.2.2 nathanw * 7 1.4.2.2 nathanw * Written by Jason R. Thorpe for Wasabi Systems, Inc. 8 1.4.2.2 nathanw * 9 1.4.2.2 nathanw * Redistribution and use in source and binary forms, with or without 10 1.4.2.2 nathanw * modification, are permitted provided that the following conditions 11 1.4.2.2 nathanw * are met: 12 1.4.2.2 nathanw * 1. Redistributions of source code must retain the above copyright 13 1.4.2.2 nathanw * notice, this list of conditions and the following disclaimer. 14 1.4.2.2 nathanw * 2. Redistributions in binary form must reproduce the above copyright 15 1.4.2.2 nathanw * notice, this list of conditions and the following disclaimer in the 16 1.4.2.2 nathanw * documentation and/or other materials provided with the distribution. 17 1.4.2.2 nathanw * 3. All advertising materials mentioning features or use of this software 18 1.4.2.2 nathanw * must display the following acknowledgement: 19 1.4.2.2 nathanw * This product includes software developed for the NetBSD Project by 20 1.4.2.2 nathanw * Wasabi Systems, Inc. 21 1.4.2.2 nathanw * 4. The name of Wasabi Systems, Inc. may not be used to endorse 22 1.4.2.2 nathanw * or promote products derived from this software without specific prior 23 1.4.2.2 nathanw * written permission. 24 1.4.2.2 nathanw * 25 1.4.2.2 nathanw * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 26 1.4.2.2 nathanw * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27 1.4.2.2 nathanw * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28 1.4.2.2 nathanw * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 29 1.4.2.2 nathanw * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 1.4.2.2 nathanw * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 1.4.2.2 nathanw * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 1.4.2.2 nathanw * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 1.4.2.2 nathanw * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 1.4.2.2 nathanw * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 1.4.2.2 nathanw * POSSIBILITY OF SUCH DAMAGE. 36 1.4.2.2 nathanw */ 37 1.4.2.2 nathanw 38 1.4.2.2 nathanw #include <machine/asm.h> 39 1.4.2.2 nathanw #include <arm/armreg.h> 40 1.4.2.2 nathanw 41 1.4.2.2 nathanw #define STACKSIZE 1024 42 1.4.2.2 nathanw 43 1.4.2.2 nathanw ENTRY(start) 44 1.4.2.2 nathanw /* 45 1.4.2.2 nathanw * We assume we've been loaded VA==PA, or that the MMU 46 1.4.2.2 nathanw * is disabled. Make sure the MMU is disabled so that 47 1.4.2.2 nathanw * we don't have to care about the caches. 48 1.4.2.2 nathanw */ 49 1.4.2.2 nathanw mrc p15, 0, r2, c1, c0, 0 50 1.4.2.2 nathanw bic r2, r2, #CPU_CONTROL_MMU_ENABLE 51 1.4.2.2 nathanw mcr p15, 0, r2, c1, c0, 0 52 1.4.2.2 nathanw 53 1.4.2.2 nathanw nop 54 1.4.2.2 nathanw nop 55 1.4.2.2 nathanw nop 56 1.4.2.2 nathanw 57 1.4.2.2 nathanw /* 58 1.4.2.2 nathanw * Check to see if __text_store == &start. If not, we're most 59 1.4.2.2 nathanw * likely running from flash. Flash is slow, and we'd 60 1.4.2.2 nathanw * really like to run the code from RAM. Copy it out. 61 1.4.2.2 nathanw */ 62 1.4.2.3 nathanw adr r1, Ltext 63 1.4.2.2 nathanw ldmia r1, {r1-r3} 64 1.4.2.2 nathanw cmp r1, r2 /* __text_store == &start? */ 65 1.4.2.2 nathanw beq relocated /* yes, in RAM */ 66 1.4.2.2 nathanw 67 1.4.2.2 nathanw /* Copy text segment from ROM to RAM */ 68 1.4.2.2 nathanw 1: ldrb r0, [r1], #0x01 69 1.4.2.2 nathanw strb r0, [r2], #0x01 70 1.4.2.2 nathanw cmp r2, r3 /* copy done? */ 71 1.4.2.2 nathanw bne 1b 72 1.4.2.2 nathanw 73 1.4.2.2 nathanw /* 74 1.4.2.2 nathanw * Okay, we are finished relocating the text segment. Now 75 1.4.2.2 nathanw * we need to leap to the next instruction. 76 1.4.2.2 nathanw */ 77 1.4.2.3 nathanw adr r1, Lrelocated 78 1.4.2.2 nathanw ldr pc, [r1] 79 1.4.2.2 nathanw 80 1.4.2.2 nathanw relocated: 81 1.4.2.2 nathanw /* 82 1.4.2.2 nathanw * Check to see if __data_store == __data_start. If not, 83 1.4.2.2 nathanw * we're most likely built for running from flash, 84 1.4.2.2 nathanw * and must copy the data segment out to RAM. 85 1.4.2.2 nathanw */ 86 1.4.2.3 nathanw adr r1, Ldata 87 1.4.2.2 nathanw ldmia r1, {r1-r3} 88 1.4.2.2 nathanw cmp r1, r2 /* __data_store == __data_start? */ 89 1.4.2.2 nathanw beq 2f /* yes, in RAM */ 90 1.4.2.2 nathanw 91 1.4.2.2 nathanw /* Copy data segment from ROM to RAM */ 92 1.4.2.2 nathanw 1: ldrb r0, [r1], #0x01 93 1.4.2.2 nathanw strb r0, [r2], #0x01 94 1.4.2.2 nathanw cmp r2, r3 /* copy done? */ 95 1.4.2.2 nathanw bne 1b 96 1.4.2.2 nathanw 97 1.4.2.2 nathanw 2: 98 1.4.2.2 nathanw /* Clear the BSS. */ 99 1.4.2.3 nathanw adr r1, Lbss 100 1.4.2.2 nathanw ldmia r1, {r1, r2} 101 1.4.2.2 nathanw sub r2, r2, r1 102 1.4.2.2 nathanw mov r3, #0 103 1.4.2.2 nathanw 104 1.4.2.2 nathanw 1: strb r3, [r1], #0x01 105 1.4.2.2 nathanw subs r2, r2, #0x01 106 1.4.2.2 nathanw bgt 1b 107 1.4.2.2 nathanw 108 1.4.2.2 nathanw /* Set the stack pointer */ 109 1.4.2.3 nathanw adr r1, Lstack 110 1.4.2.2 nathanw ldr r1, [r1] 111 1.4.2.2 nathanw add sp, r1, #STACKSIZE 112 1.4.2.2 nathanw 113 1.4.2.2 nathanw b _C_LABEL(main) 114 1.4.2.2 nathanw 115 1.4.2.2 nathanw Lrelocated: 116 1.4.2.2 nathanw .word relocated 117 1.4.2.2 nathanw 118 1.4.2.2 nathanw Ltext: 119 1.4.2.2 nathanw .word _C_LABEL(__text_store) 120 1.4.2.2 nathanw .word _C_LABEL(start) 121 1.4.2.2 nathanw .word _C_LABEL(_etext) 122 1.4.2.2 nathanw 123 1.4.2.2 nathanw Ldata: 124 1.4.2.2 nathanw .word _C_LABEL(__data_store) 125 1.4.2.2 nathanw .word _C_LABEL(__data_start) 126 1.4.2.2 nathanw 127 1.4.2.2 nathanw Lbss: 128 1.4.2.2 nathanw .word _C_LABEL(_edata) 129 1.4.2.2 nathanw .word _C_LABEL(_end) 130 1.4.2.2 nathanw 131 1.4.2.2 nathanw Lstack: 132 1.4.2.2 nathanw .word Lstackspace 133 1.4.2.2 nathanw 134 1.4.2.2 nathanw .comm Lstackspace, STACKSIZE 135
Indexes created Sat Nov 01 21:09:44 GMT 2025