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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 | // SPDX-License-Identifier: GPL-2.0-only // Copyright (C) 2015-2021 ARM Limited. // Original author: Dave Martin <Dave.Martin@arm.com> // // Utility functions for assembly code. #include <asm/unistd.h> #include "assembler.h" // Print a single character x0 to stdout // Clobbers x0-x2,x8 function putc str x0, [sp, #-16]! mov x0, #1 // STDOUT_FILENO mov x1, sp mov x2, #1 mov x8, #__NR_write svc #0 add sp, sp, #16 ret endfunction .globl putc // Print a NUL-terminated string starting at address x0 to stdout // Clobbers x0-x3,x8 function puts mov x1, x0 mov x2, #0 0: ldrb w3, [x0], #1 cbz w3, 1f add x2, x2, #1 b 0b 1: mov w0, #1 // STDOUT_FILENO mov x8, #__NR_write svc #0 ret endfunction .globl puts // Print an unsigned decimal number x0 to stdout // Clobbers x0-x4,x8 function putdec mov x1, sp str x30, [sp, #-32]! // Result can't be > 20 digits mov x2, #0 strb w2, [x1, #-1]! // Write the NUL terminator mov x2, #10 0: udiv x3, x0, x2 // div-mod loop to generate the digits msub x0, x3, x2, x0 add w0, w0, #'0' strb w0, [x1, #-1]! mov x0, x3 cbnz x3, 0b ldrb w0, [x1] cbnz w0, 1f mov w0, #'0' // Print "0" for 0, not "" strb w0, [x1, #-1]! 1: mov x0, x1 bl puts ldr x30, [sp], #32 ret endfunction .globl putdec // Print an unsigned decimal number x0 to stdout, followed by a newline // Clobbers x0-x5,x8 function putdecn mov x5, x30 bl putdec mov x0, #'\n' bl putc ret x5 endfunction .globl putdecn // Clobbers x0-x3,x8 function puthexb str x30, [sp, #-0x10]! mov w3, w0 lsr w0, w0, #4 bl puthexnibble mov w0, w3 ldr x30, [sp], #0x10 // fall through to puthexnibble endfunction .globl puthexb // Clobbers x0-x2,x8 function puthexnibble and w0, w0, #0xf cmp w0, #10 blo 1f add w0, w0, #'a' - ('9' + 1) 1: add w0, w0, #'0' b putc endfunction .globl puthexnibble // x0=data in, x1=size in, clobbers x0-x5,x8 function dumphex str x30, [sp, #-0x10]! mov x4, x0 mov x5, x1 0: subs x5, x5, #1 b.lo 1f ldrb w0, [x4], #1 bl puthexb b 0b 1: ldr x30, [sp], #0x10 ret endfunction .globl dumphex // Trivial memory copy: copy x2 bytes, starting at address x1, to address x0. // Clobbers x0-x3 function memcpy cmp x2, #0 b.eq 1f 0: ldrb w3, [x1], #1 strb w3, [x0], #1 subs x2, x2, #1 b.ne 0b 1: ret endfunction .globl memcpy // Fill x1 bytes starting at x0 with 0xae (for canary purposes) // Clobbers x1, x2. function memfill_ae mov w2, #0xae b memfill endfunction .globl memfill_ae // Fill x1 bytes starting at x0 with 0. // Clobbers x1, x2. function memclr mov w2, #0 endfunction .globl memclr // fall through to memfill // Trivial memory fill: fill x1 bytes starting at address x0 with byte w2 // Clobbers x1 function memfill cmp x1, #0 b.eq 1f 0: strb w2, [x0], #1 subs x1, x1, #1 b.ne 0b 1: ret endfunction .globl memfill |