len0rd/rockbox
1
0
Fork 1
mirror of https://github.com/Rockbox/rockbox.git synced 2025-12-09 05:05:20 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

ARM asm LCD and ATA driver functions: Don't save r12 as it is a scratch reg. Saves a bit of stack and execution time.

Browse source 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21795 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jens Arnold 2009-07-11 23:43:44 +00:00
parent fa59ed6ae7
commit 47d4c4739b
12 changed files with 256 additions and 261 deletions
Download patch file Download diff file Expand all files Collapse all files

29
firmware/target/arm/olympus/mrobe-100/lcd-as-mr100.S
View file

@ -30,21 +30,20 @@
.type lcd_write_data,%function
lcd_write_data:
str lr, [sp, #-4]!
ldr lr, =LCD1_BASE
ldr r12, =LCD1_BASE
.loop:
ldrb r2, [r0], #1
1:
ldr r3, [lr]
ldr r3, [r12]
tst r3, #LCD1_BUSY_MASK
bne 1b
str r2, [lr, #0x10]
str r2, [r12, #0x10]
subs r1, r1, #1
bne .loop
ldr pc, [sp], #4
bx lr
.size lcd_write_data,.-lcd_write_data
@ -62,16 +61,16 @@ lcd_write_data:
* Register usage:
* r3/r4 - current block of phases
* r5/r6 - current block of values
* r7 - lcd data accumulator
* r8 - phase signs mask
* lr - lcd bridge address
* r7 - lcd data accumulator
* r12 - phase signs mask
* lr - lcd bridge address
*/
lcd_grey_data:
stmfd sp!, {r4-r8, lr}
mov r8, #0x80
orr r8, r8, r8, lsl #8
orr r8, r8, r8, lsl #16
stmfd sp!, {r4-r7, lr}
mov r12, #0x80
orr r12, r12, r12, lsl #8
orr r12, r12, r12, lsl #16
ldr lr, =LCD1_BASE
.greyloop:
@ -87,7 +86,7 @@ lcd_grey_data:
biceq r7, r7, #0x20
tst r3, #0x80000000
biceq r7, r7, #0x10
bic r3, r3, r8
bic r3, r3, r12
add r3, r3, r5
tst r4, #0x80
@ -98,7 +97,7 @@ lcd_grey_data:
biceq r7, r7, #0x02
tst r4, #0x80000000
biceq r7, r7, #0x01
bic r4, r4, r8
bic r4, r4, r12
add r4, r4, r6
stmia r1!, {r3-r4}
@ -112,6 +111,6 @@ lcd_grey_data:
subs r2, r2, #1
bne .greyloop
ldmfd sp!, {r4-r8, pc}
ldmfd sp!, {r4-r7, pc}
.size lcd_grey_data,.-lcd_grey_data