rockbox/apps/plugins/pacbox/pacbox_arm.S
Rafaël Carré 45c7498f59 FS#11335 by me: make ARM assembly functions thumb-friendly
We can't pop into pc on ARMv4t when using thumb: the T bit won't be
modified if we are returning to a thumb function
Code running on ARMv4t should use the new ldrpc / ldmpc macros instead
of ldr pc, [sp], #4 and ldm(cond) sp!, {regs, pc}
No modification on pure ARM builds and ARMv5+

Note: USE_THUMB is currently never defined, no targets can currently be
built with -mthumb, see FS#6734

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26756 a1c6a512-1295-4272-9138-f99709370657
2010-06-11 04:41:36 +00:00

127 lines
4.1 KiB
ArmAsm

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (c) 2006 Dave Chapman
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "pacbox.h"
.section .icode,"ax",%progbits
.global blit_display
/* void blit_display(fb_data* lcd_framebuffer, unsigned char* vbuf)
next_dst=&lcd_framebuffer[YOFS*LCD_WIDTH+XOFS+ScreenHeight-1];
for( y=ScreenHeight; y>0; y-- ) {
dst = (next_dst--);
for( x=ScreenWidth; x>0; x-- ) {
*dst = palette[*(vbuf++)];
dst+=LCD_WIDTH;
}
}
*/
#ifdef HAVE_LCD_COLOR
#if (LCD_WIDTH >= 288) && (LCD_HEIGHT >= 224)
blit_display:
stmdb sp!, {r4-r11, lr}
add r3, r0, #5696
add r3, r3, #24 @ 5720 = (2*(YOFS*LCD_WIDTH+XOFS+ScreenHeight-4))
ldr r0, =palette
mov lr, #288 @ y = 288
loop_y: mov r2, r3 @ r2 = next_dst
sub r3, r3, #8 @ next_dst-=4
mov ip, #224 @ x = 224
/* store 2 input bytes from the next four lines in r7-r10 */
loop_x:
ldrh r8, [r1, #224] @ r8 = vbuf[224]
ldrh r7, [r1] @ r7 = vbuf[0]
add r1, r1, #448
ldrh r10, [r1, #224] @ r10 = vbuf[224*3]
ldrh r9, [r1], #2 @ r9 = vbuf[224*2] ; vbuf += 2;
sub r1, r1, #448
/* Convert high bytes of r7-r10 into palette entries in r5 and r6 */
mov r6, r7, lsr #8
mov r6, r6, lsl #1
ldrh r6, [r6, r0] @ r6 = palette[hi(r7]]
mov r11, r8, lsr #8
mov r11, r11, lsl #1
ldrh r11, [r11, r0] @ r11 = palette[hi(r8]]
orr r6, r11, r6, lsl #16 @ r6 = palette[hi(r8]]
@ | (palette[hi(r7)] << 16)
mov r5, r9, lsr #8
mov r5, r5, lsl #1
ldrh r5, [r5, r0] @ r5 = palette[hi(r9]]
mov r11, r10, lsr #8
mov r11, r11, lsl #1
ldrh r11, [r11, r0] @ r11 = palette[hi(r10)]]
orr r5, r11, r5, lsl #16 @ r5 = palette[hi(r10]]
@ | (palette[hi(r9)] << 16)
/* Convert low bytes of r7-r10 into palette entries in r7 and r8 */
and r7, r7, #0xff
mov r7, r7, lsl #1
ldrh r7, [r7, r0]
and r8, r8, #0xff
mov r8, r8, lsl #1
ldrh r8, [r8, r0]
orr r8, r8, r7, lsl #16
and r9, r9, #0xff
mov r9, r9, lsl #1
ldrh r9, [r9, r0]
and r10, r10, #0xff
mov r10, r10, lsl #1
ldrh r10, [r10, r0]
orr r7, r10, r9, lsl #16
/* Now write the 8 pixels to the screen */
stmia r2!, {r7, r8}
add r2, r2, #(LCD_WIDTH*2)-8 @ dst += LCD_WIDTH
stmia r2!, {r5, r6}
add r2, r2, #(LCD_WIDTH*2)-8 @ dst += LCD_WIDTH
/* end of x loop */
subs ip, ip, #2 @ x-=2
bne loop_x
/* end of y loop */
add r1, r1, #224*3 @ vbuf += 224*3
subs lr, lr, #4 @ y-=4
ldmpc cond=eq, regs=r4-r11
b loop_y
#endif
#endif