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-rw-r--r--firmware/bitswap.S125
1 files changed, 58 insertions, 67 deletions
diff --git a/firmware/bitswap.S b/firmware/bitswap.S
index 5f94fedb36..f825be22d1 100644
--- a/firmware/bitswap.S
+++ b/firmware/bitswap.S
@@ -17,85 +17,76 @@
17 * 17 *
18 ****************************************************************************/ 18 ****************************************************************************/
19 19
20 .section .icode,"ax",@progbits 20 .section .icode,"ax",@progbits
21 .global _bitswap 21 .global _bitswap
22 .align 4 22 .align 4
23 .type _bitswap,@function 23 .type _bitswap,@function
24 24
25/* Registers used: 25/* Registers used:
26 * 26 *
27 * r0 Temporary (required by some instructions) 27 * r0 Temporary (required by some instructions)
28 * r1 Low byte 28 * r1 Flip table
29 * r2 High byte 29 * r4 Argument: Data pointer
30 * r3 Result after flip 30 * r5 Argument: Length (in bytes)
31 * r4 Data
32 * r5 Length
33 * r6 Current (position in Data)
34 * r7 Flip table
35 */ 31 */
36 32
33/* TODO: Optimize for DRAM burst operation by reading and writing in chunks
34 We do not want to optimize by reading/writing words, because the data
35 pointer may be odd */
36
37_bitswap: 37_bitswap:
38 mov.l .fliptable,r7 38 mov.l .fliptable,r1
39 mov r4,r6 39 add r4,r5 /* Calculate end of buffer */
40 add r5,r6 /* goto end of buffer */ 40 bra .init
41 add r5,r6 /* (direction IS important) */
42 bra .init
43.loop: 41.loop:
44 mov.w @r4,r1 /* data to flip */ 42 mov.b @r4,r0 /* Data to flip */
45 swap.b r1,r2 43 extu.b r0,r0 /* Zero extend */
46 extu.b r2,r0 /* high byte */ 44 mov.b @(r0,r1),r0 /* Look up in the flip table */
47 mov.b @(r0,r7),r2 45 mov.b r0,@r4 /* Store result */
48 extu.b r2,r0 /* remove any sign extend */ 46 add #1,r4
49 swap.b r0,r3 /* put high byte in result */
50 extu.b r1,r0 /* low byte */
51 mov.b @(r0,r7),r1
52 extu.b r1,r0 /* remove any sign extend */
53 or r0,r3 /* put low byte in result */
54 mov.w r3,@r4 /* store result */
55 add #2,r4
56.init: 47.init:
57 cmp/gt r4,r6 /* while (data < start+length*2) */ 48 cmp/gt r4,r5 /* while (dataptr < start+length) */
58 bt .loop 49 bt .loop
59 rts 50 rts
60 51
61 .align 4 52 .align 4
62 53
63.fliptable: 54.fliptable:
64 .long _fliptable 55 .long _fliptable
65 56
66_fliptable: 57_fliptable:
67 .byte 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0 58 .byte 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0
68 .byte 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0 59 .byte 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0
69 .byte 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8 60 .byte 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8
70 .byte 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8 61 .byte 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8
71 .byte 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4 62 .byte 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4
72 .byte 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4 63 .byte 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4
73 .byte 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec 64 .byte 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec
74 .byte 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc 65 .byte 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc
75 .byte 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2 66 .byte 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2
76 .byte 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2 67 .byte 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2
77 .byte 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea 68 .byte 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea
78 .byte 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa 69 .byte 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa
79 .byte 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6 70 .byte 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6
80 .byte 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6 71 .byte 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6
81 .byte 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee 72 .byte 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee
82 .byte 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe 73 .byte 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe
83 .byte 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1 74 .byte 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1
84 .byte 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1 75 .byte 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1
85 .byte 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9 76 .byte 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9
86 .byte 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9 77 .byte 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9
87 .byte 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5 78 .byte 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5
88 .byte 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5 79 .byte 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5
89 .byte 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed 80 .byte 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed
90 .byte 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd 81 .byte 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd
91 .byte 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3 82 .byte 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3
92 .byte 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3 83 .byte 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3
93 .byte 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb 84 .byte 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb
94 .byte 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb 85 .byte 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb
95 .byte 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7 86 .byte 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7
96 .byte 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7 87 .byte 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7
97 .byte 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef 88 .byte 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef
98 .byte 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff 89 .byte 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff
99 90
100.end: 91.end:
101 .size _bitswap,.end-_bitswap 92 .size _bitswap,.end-_bitswap
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-29 15:29:01 +0000