1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * linux/arch/arm/lib/ll_char_wr.S 4 * 5 * Copyright (C) 1995, 1996 Russell King. 6 * 7 * Speedups & 1bpp code (C) 1996 Philip Blundell & Russell King. 8 * 9 * 10-04-96 RMK Various cleanups & reduced register usage. 10 * 08-04-98 RMK Shifts re-ordered 11 */ 12 13@ Regs: [] = corruptible 14@ {} = used 15@ () = do not use 16 17#include <linux/linkage.h> 18#include <asm/assembler.h> 19 .text 20 21LC0: .word LC0 22 .word bytes_per_char_h 23 .word video_size_row 24 .word acorndata_8x8 25 .word con_charconvtable 26 27/* 28 * r0 = ptr 29 * r1 = char 30 * r2 = white 31 */ 32ENTRY(ll_write_char) 33 stmfd sp!, {r4 - r7, lr} 34@ 35@ Smashable regs: {r0 - r3}, [r4 - r7], (r8 - fp), [ip], (sp), [lr], (pc) 36@ 37 /* 38 * calculate offset into character table 39 */ 40 mov r1, r1, lsl #3 41 /* 42 * calculate offset required for each row. 43 */ 44 adr ip, LC0 45 ldmia ip, {r3, r4, r5, r6, lr} 46 sub ip, ip, r3 47 add r6, r6, ip 48 add lr, lr, ip 49 ldr r4, [r4, ip] 50 ldr r5, [r5, ip] 51 /* 52 * Go to resolution-dependent routine... 53 */ 54 cmp r4, #4 55 blt Lrow1bpp 56 add r0, r0, r5, lsl #3 @ Move to bottom of character 57 orr r1, r1, #7 58 ldrb r7, [r6, r1] 59 teq r4, #8 60 beq Lrow8bpplp 61@ 62@ Smashable regs: {r0 - r3}, [r4], {r5 - r7}, (r8 - fp), [ip], (sp), {lr}, (pc) 63@ 64Lrow4bpplp: 65 ldr r7, [lr, r7, lsl #2] 66 mul r7, r2, r7 67 sub r1, r1, #1 @ avoid using r7 directly after 68 str r7, [r0, -r5]! 69 ldrb r7, [r6, r1] 70 ldr r7, [lr, r7, lsl #2] 71 mul r7, r2, r7 72 tst r1, #7 @ avoid using r7 directly after 73 str r7, [r0, -r5]! 74 subne r1, r1, #1 75 ldrbne r7, [r6, r1] 76 bne Lrow4bpplp 77 ldmfd sp!, {r4 - r7, pc} 78 79@ 80@ Smashable regs: {r0 - r3}, [r4], {r5 - r7}, (r8 - fp), [ip], (sp), {lr}, (pc) 81@ 82Lrow8bpplp: 83 mov ip, r7, lsr #4 84 ldr ip, [lr, ip, lsl #2] 85 mul r4, r2, ip 86 and ip, r7, #15 @ avoid r4 87 ldr ip, [lr, ip, lsl #2] @ avoid r4 88 mul ip, r2, ip @ avoid r4 89 sub r1, r1, #1 @ avoid ip 90 sub r0, r0, r5 @ avoid ip 91 stmia r0, {r4, ip} 92 ldrb r7, [r6, r1] 93 mov ip, r7, lsr #4 94 ldr ip, [lr, ip, lsl #2] 95 mul r4, r2, ip 96 and ip, r7, #15 @ avoid r4 97 ldr ip, [lr, ip, lsl #2] @ avoid r4 98 mul ip, r2, ip @ avoid r4 99 tst r1, #7 @ avoid ip 100 sub r0, r0, r5 @ avoid ip 101 stmia r0, {r4, ip} 102 subne r1, r1, #1 103 ldrbne r7, [r6, r1] 104 bne Lrow8bpplp 105 ldmfd sp!, {r4 - r7, pc} 106 107@ 108@ Smashable regs: {r0 - r3}, [r4], {r5, r6}, [r7], (r8 - fp), [ip], (sp), [lr], (pc) 109@ 110Lrow1bpp: 111 add r6, r6, r1 112 ldmia r6, {r4, r7} 113 strb r4, [r0], r5 114 mov r4, r4, lsr #8 115 strb r4, [r0], r5 116 mov r4, r4, lsr #8 117 strb r4, [r0], r5 118 mov r4, r4, lsr #8 119 strb r4, [r0], r5 120 strb r7, [r0], r5 121 mov r7, r7, lsr #8 122 strb r7, [r0], r5 123 mov r7, r7, lsr #8 124 strb r7, [r0], r5 125 mov r7, r7, lsr #8 126 strb r7, [r0], r5 127 ldmfd sp!, {r4 - r7, pc} 128 129 .bss 130ENTRY(con_charconvtable) 131 .space 1024 132