diff options
Diffstat (limited to 'arch/arm/boot/compressed/ll_char_wr.S')
-rw-r--r-- | arch/arm/boot/compressed/ll_char_wr.S | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/arch/arm/boot/compressed/ll_char_wr.S b/arch/arm/boot/compressed/ll_char_wr.S new file mode 100644 index 0000000000..1ec8cb2898 --- /dev/null +++ b/arch/arm/boot/compressed/ll_char_wr.S @@ -0,0 +1,131 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/lib/ll_char_wr.S + * + * Copyright (C) 1995, 1996 Russell King. + * + * Speedups & 1bpp code (C) 1996 Philip Blundell & Russell King. + * + * 10-04-96 RMK Various cleanups & reduced register usage. + * 08-04-98 RMK Shifts re-ordered + */ + +@ Regs: [] = corruptible +@ {} = used +@ () = do not use + +#include <linux/linkage.h> +#include <asm/assembler.h> + .text + +LC0: .word LC0 + .word bytes_per_char_h + .word video_size_row + .word acorndata_8x8 + .word con_charconvtable + +/* + * r0 = ptr + * r1 = char + * r2 = white + */ +ENTRY(ll_write_char) + stmfd sp!, {r4 - r7, lr} +@ +@ Smashable regs: {r0 - r3}, [r4 - r7], (r8 - fp), [ip], (sp), [lr], (pc) +@ + /* + * calculate offset into character table + */ + mov r1, r1, lsl #3 + /* + * calculate offset required for each row. + */ + adr ip, LC0 + ldmia ip, {r3, r4, r5, r6, lr} + sub ip, ip, r3 + add r6, r6, ip + add lr, lr, ip + ldr r4, [r4, ip] + ldr r5, [r5, ip] + /* + * Go to resolution-dependent routine... + */ + cmp r4, #4 + blt Lrow1bpp + add r0, r0, r5, lsl #3 @ Move to bottom of character + orr r1, r1, #7 + ldrb r7, [r6, r1] + teq r4, #8 + beq Lrow8bpplp +@ +@ Smashable regs: {r0 - r3}, [r4], {r5 - r7}, (r8 - fp), [ip], (sp), {lr}, (pc) +@ +Lrow4bpplp: + ldr r7, [lr, r7, lsl #2] + mul r7, r2, r7 + sub r1, r1, #1 @ avoid using r7 directly after + str r7, [r0, -r5]! + ldrb r7, [r6, r1] + ldr r7, [lr, r7, lsl #2] + mul r7, r2, r7 + tst r1, #7 @ avoid using r7 directly after + str r7, [r0, -r5]! + subne r1, r1, #1 + ldrbne r7, [r6, r1] + bne Lrow4bpplp + ldmfd sp!, {r4 - r7, pc} + +@ +@ Smashable regs: {r0 - r3}, [r4], {r5 - r7}, (r8 - fp), [ip], (sp), {lr}, (pc) +@ +Lrow8bpplp: + mov ip, r7, lsr #4 + ldr ip, [lr, ip, lsl #2] + mul r4, r2, ip + and ip, r7, #15 @ avoid r4 + ldr ip, [lr, ip, lsl #2] @ avoid r4 + mul ip, r2, ip @ avoid r4 + sub r1, r1, #1 @ avoid ip + sub r0, r0, r5 @ avoid ip + stmia r0, {r4, ip} + ldrb r7, [r6, r1] + mov ip, r7, lsr #4 + ldr ip, [lr, ip, lsl #2] + mul r4, r2, ip + and ip, r7, #15 @ avoid r4 + ldr ip, [lr, ip, lsl #2] @ avoid r4 + mul ip, r2, ip @ avoid r4 + tst r1, #7 @ avoid ip + sub r0, r0, r5 @ avoid ip + stmia r0, {r4, ip} + subne r1, r1, #1 + ldrbne r7, [r6, r1] + bne Lrow8bpplp + ldmfd sp!, {r4 - r7, pc} + +@ +@ Smashable regs: {r0 - r3}, [r4], {r5, r6}, [r7], (r8 - fp), [ip], (sp), [lr], (pc) +@ +Lrow1bpp: + add r6, r6, r1 + ldmia r6, {r4, r7} + strb r4, [r0], r5 + mov r4, r4, lsr #8 + strb r4, [r0], r5 + mov r4, r4, lsr #8 + strb r4, [r0], r5 + mov r4, r4, lsr #8 + strb r4, [r0], r5 + strb r7, [r0], r5 + mov r7, r7, lsr #8 + strb r7, [r0], r5 + mov r7, r7, lsr #8 + strb r7, [r0], r5 + mov r7, r7, lsr #8 + strb r7, [r0], r5 + ldmfd sp!, {r4 - r7, pc} + + .bss +ENTRY(con_charconvtable) + .space 1024 |