Creation of Cybook 2416 (actually Gen4) repository

arch/arm/boot/compressed/ll_char_wr.S

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+/*
+ *  linux/arch/arm/lib/ll_char_wr.S
+ *
+ *  Copyright (C) 1995, 1996 Russell King.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  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
+	ldrneb	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
+	ldrneb	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