xref: /OK3568_Linux_fs/kernel/arch/arm/boot/compressed/ll_char_wr.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0-only */
2*4882a593Smuzhiyun/*
3*4882a593Smuzhiyun *  linux/arch/arm/lib/ll_char_wr.S
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun *  Copyright (C) 1995, 1996 Russell King.
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun *  Speedups & 1bpp code (C) 1996 Philip Blundell & Russell King.
8*4882a593Smuzhiyun *
9*4882a593Smuzhiyun *  10-04-96	RMK	Various cleanups & reduced register usage.
10*4882a593Smuzhiyun *  08-04-98	RMK	Shifts re-ordered
11*4882a593Smuzhiyun */
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun@ Regs: [] = corruptible
14*4882a593Smuzhiyun@       {} = used
15*4882a593Smuzhiyun@       () = do not use
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun#include <linux/linkage.h>
18*4882a593Smuzhiyun#include <asm/assembler.h>
19*4882a593Smuzhiyun	.text
20*4882a593Smuzhiyun
21*4882a593SmuzhiyunLC0:	.word	LC0
22*4882a593Smuzhiyun	.word	bytes_per_char_h
23*4882a593Smuzhiyun	.word	video_size_row
24*4882a593Smuzhiyun	.word	acorndata_8x8
25*4882a593Smuzhiyun	.word	con_charconvtable
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun/*
28*4882a593Smuzhiyun * r0 = ptr
29*4882a593Smuzhiyun * r1 = char
30*4882a593Smuzhiyun * r2 = white
31*4882a593Smuzhiyun */
32*4882a593SmuzhiyunENTRY(ll_write_char)
33*4882a593Smuzhiyun	stmfd	sp!, {r4 - r7, lr}
34*4882a593Smuzhiyun@
35*4882a593Smuzhiyun@ Smashable regs: {r0 - r3}, [r4 - r7], (r8 - fp), [ip], (sp), [lr], (pc)
36*4882a593Smuzhiyun@
37*4882a593Smuzhiyun	/*
38*4882a593Smuzhiyun	 * calculate offset into character table
39*4882a593Smuzhiyun	 */
40*4882a593Smuzhiyun	mov	r1, r1, lsl #3
41*4882a593Smuzhiyun	/*
42*4882a593Smuzhiyun	 * calculate offset required for each row.
43*4882a593Smuzhiyun	 */
44*4882a593Smuzhiyun	adr	ip, LC0
45*4882a593Smuzhiyun	ldmia	ip, {r3, r4, r5, r6, lr}
46*4882a593Smuzhiyun	sub	ip, ip, r3
47*4882a593Smuzhiyun	add	r6, r6, ip
48*4882a593Smuzhiyun	add	lr, lr, ip
49*4882a593Smuzhiyun	ldr	r4, [r4, ip]
50*4882a593Smuzhiyun	ldr	r5, [r5, ip]
51*4882a593Smuzhiyun	/*
52*4882a593Smuzhiyun	 * Go to resolution-dependent routine...
53*4882a593Smuzhiyun	 */
54*4882a593Smuzhiyun	cmp	r4, #4
55*4882a593Smuzhiyun	blt	Lrow1bpp
56*4882a593Smuzhiyun	add	r0, r0, r5, lsl #3		@ Move to bottom of character
57*4882a593Smuzhiyun	orr	r1, r1, #7
58*4882a593Smuzhiyun	ldrb	r7, [r6, r1]
59*4882a593Smuzhiyun	teq	r4, #8
60*4882a593Smuzhiyun	beq	Lrow8bpplp
61*4882a593Smuzhiyun@
62*4882a593Smuzhiyun@ Smashable regs: {r0 - r3}, [r4], {r5 - r7}, (r8 - fp), [ip], (sp), {lr}, (pc)
63*4882a593Smuzhiyun@
64*4882a593SmuzhiyunLrow4bpplp:
65*4882a593Smuzhiyun	ldr	r7, [lr, r7, lsl #2]
66*4882a593Smuzhiyun	mul	r7, r2, r7
67*4882a593Smuzhiyun	sub	r1, r1, #1			@ avoid using r7 directly after
68*4882a593Smuzhiyun	str	r7, [r0, -r5]!
69*4882a593Smuzhiyun	ldrb	r7, [r6, r1]
70*4882a593Smuzhiyun	ldr	r7, [lr, r7, lsl #2]
71*4882a593Smuzhiyun	mul	r7, r2, r7
72*4882a593Smuzhiyun	tst	r1, #7				@ avoid using r7 directly after
73*4882a593Smuzhiyun	str	r7, [r0, -r5]!
74*4882a593Smuzhiyun	subne	r1, r1, #1
75*4882a593Smuzhiyun	ldrbne	r7, [r6, r1]
76*4882a593Smuzhiyun	bne	Lrow4bpplp
77*4882a593Smuzhiyun	ldmfd	sp!, {r4 - r7, pc}
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun@
80*4882a593Smuzhiyun@ Smashable regs: {r0 - r3}, [r4], {r5 - r7}, (r8 - fp), [ip], (sp), {lr}, (pc)
81*4882a593Smuzhiyun@
82*4882a593SmuzhiyunLrow8bpplp:
83*4882a593Smuzhiyun	mov	ip, r7, lsr #4
84*4882a593Smuzhiyun	ldr	ip, [lr, ip, lsl #2]
85*4882a593Smuzhiyun	mul	r4, r2, ip
86*4882a593Smuzhiyun	and	ip, r7, #15			@ avoid r4
87*4882a593Smuzhiyun	ldr	ip, [lr, ip, lsl #2]		@ avoid r4
88*4882a593Smuzhiyun	mul	ip, r2, ip			@ avoid r4
89*4882a593Smuzhiyun	sub	r1, r1, #1			@ avoid ip
90*4882a593Smuzhiyun	sub	r0, r0, r5			@ avoid ip
91*4882a593Smuzhiyun	stmia	r0, {r4, ip}
92*4882a593Smuzhiyun	ldrb	r7, [r6, r1]
93*4882a593Smuzhiyun	mov	ip, r7, lsr #4
94*4882a593Smuzhiyun	ldr	ip, [lr, ip, lsl #2]
95*4882a593Smuzhiyun	mul	r4, r2, ip
96*4882a593Smuzhiyun	and	ip, r7, #15			@ avoid r4
97*4882a593Smuzhiyun	ldr	ip, [lr, ip, lsl #2]		@ avoid r4
98*4882a593Smuzhiyun	mul	ip, r2, ip			@ avoid r4
99*4882a593Smuzhiyun	tst	r1, #7				@ avoid ip
100*4882a593Smuzhiyun	sub	r0, r0, r5			@ avoid ip
101*4882a593Smuzhiyun	stmia	r0, {r4, ip}
102*4882a593Smuzhiyun	subne	r1, r1, #1
103*4882a593Smuzhiyun	ldrbne	r7, [r6, r1]
104*4882a593Smuzhiyun	bne	Lrow8bpplp
105*4882a593Smuzhiyun	ldmfd	sp!, {r4 - r7, pc}
106*4882a593Smuzhiyun
107*4882a593Smuzhiyun@
108*4882a593Smuzhiyun@ Smashable regs: {r0 - r3}, [r4], {r5, r6}, [r7], (r8 - fp), [ip], (sp), [lr], (pc)
109*4882a593Smuzhiyun@
110*4882a593SmuzhiyunLrow1bpp:
111*4882a593Smuzhiyun	add	r6, r6, r1
112*4882a593Smuzhiyun	ldmia	r6, {r4, r7}
113*4882a593Smuzhiyun	strb	r4, [r0], r5
114*4882a593Smuzhiyun	mov	r4, r4, lsr #8
115*4882a593Smuzhiyun	strb	r4, [r0], r5
116*4882a593Smuzhiyun	mov	r4, r4, lsr #8
117*4882a593Smuzhiyun	strb	r4, [r0], r5
118*4882a593Smuzhiyun	mov	r4, r4, lsr #8
119*4882a593Smuzhiyun	strb	r4, [r0], r5
120*4882a593Smuzhiyun	strb	r7, [r0], r5
121*4882a593Smuzhiyun	mov	r7, r7, lsr #8
122*4882a593Smuzhiyun	strb	r7, [r0], r5
123*4882a593Smuzhiyun	mov	r7, r7, lsr #8
124*4882a593Smuzhiyun	strb	r7, [r0], r5
125*4882a593Smuzhiyun	mov	r7, r7, lsr #8
126*4882a593Smuzhiyun	strb	r7, [r0], r5
127*4882a593Smuzhiyun	ldmfd	sp!, {r4 - r7, pc}
128*4882a593Smuzhiyun
129*4882a593Smuzhiyun	.bss
130*4882a593SmuzhiyunENTRY(con_charconvtable)
131*4882a593Smuzhiyun	.space	1024
132