| 1 | @ vim:filetype=armasm |
| 2 | |
| 3 | @ test |
| 4 | .global flushcache @ beginning_addr, end_addr, flags |
| 5 | |
| 6 | flushcache: |
| 7 | swi #0x9f0002 |
| 8 | mov pc, lr |
| 9 | |
| 10 | |
| 11 | /* buggy and slow, probably because function call overhead |
| 12 | @ renderer helper, based on bitbank's method |
| 13 | .global draw8pix @ uint8 *P, uint8 *C, uint8 *PALRAM @ dest, src, pal |
| 14 | |
| 15 | draw8pix: |
| 16 | stmfd sp!, {r4,r5} |
| 17 | |
| 18 | ldrb r3, [r1] @ get bit 0 pixels |
| 19 | mov r12,#1 |
| 20 | orr r12,r12,r12,lsl #8 |
| 21 | orr r12,r12,r12,lsl #16 |
| 22 | ldrb r1, [r1, #8] @ get bit 1 pixels |
| 23 | orr r3, r3, r3, lsl #9 @ shift them over 1 byte + 1 bit |
| 24 | orr r3, r3, r3, lsl #18 @ now 4 pixels take up 4 bytes |
| 25 | and r4, r12,r3, lsr #7 @ mask off the upper nibble pixels we want |
| 26 | and r5, r12,r3, lsr #3 @ mask off the lower nibble pixels we want |
| 27 | ldr r2, [r2] |
| 28 | |
| 29 | orr r1, r1, r1, lsl #9 @ process the bit 1 pixels |
| 30 | orr r1, r1, r1, lsl #18 |
| 31 | and r3, r12,r1, lsr #7 @ mask off the upper nibble pixels we want |
| 32 | and r1, r12,r1, lsr #3 @ mask off the lower nibble |
| 33 | orr r4, r4, r3, lsl #1 |
| 34 | orr r5, r5, r1, lsl #5 |
| 35 | |
| 36 | @ can this be avoided? |
| 37 | mov r4, r4, lsl #3 @ *8 |
| 38 | mov r3, r2, ror r4 |
| 39 | strb r3, [r0], #1 |
| 40 | mov r4, r4, lsr #8 |
| 41 | mov r3, r2, ror r4 |
| 42 | strb r3, [r0], #1 |
| 43 | mov r4, r4, lsr #8 |
| 44 | mov r3, r2, ror r4 |
| 45 | strb r3, [r0], #1 |
| 46 | mov r4, r4, lsr #8 |
| 47 | mov r3, r2, ror r4 |
| 48 | strb r3, [r0], #1 |
| 49 | |
| 50 | mov r5, r5, lsl #3 @ *8 |
| 51 | mov r3, r2, ror r5 |
| 52 | strb r3, [r0], #1 |
| 53 | mov r5, r5, lsr #8 |
| 54 | mov r3, r2, ror r5 |
| 55 | strb r3, [r0], #1 |
| 56 | mov r5, r5, lsr #8 |
| 57 | mov r3, r2, ror r5 |
| 58 | strb r3, [r0], #1 |
| 59 | mov r5, r5, lsr #8 |
| 60 | mov r3, r2, ror r5 |
| 61 | strb r3, [r0], #1 |
| 62 | |
| 63 | ldmfd sp!, {r4,r5} |
| 64 | bx lr |
| 65 | */ |
| 66 | |