Root/target/linux/brcm-2.4/image/lzma-loader/src/head.S

1/* Copyright 2005 Oleg I. Vdovikin (oleg@cs.msu.su) */
2/* cache manipulation adapted from Broadcom code */
3/* idea taken from original bunzip2 decompressor code */
4/* Copyright 2004 Manuel Novoa III (mjn3@codepoet.org) */
5/* Licensed under the linux kernel's version of the GPL.*/
6
7#include <asm/asm.h>
8#include <asm/regdef.h>
9
10#define KSEG0 0x80000000
11
12#define C0_CONFIG $16
13#define C0_TAGLO $28
14#define C0_TAGHI $29
15
16#define CONF1_DA_SHIFT 7 /* D$ associativity */
17#define CONF1_DA_MASK 0x00000380
18#define CONF1_DA_BASE 1
19#define CONF1_DL_SHIFT 10 /* D$ line size */
20#define CONF1_DL_MASK 0x00001c00
21#define CONF1_DL_BASE 2
22#define CONF1_DS_SHIFT 13 /* D$ sets/way */
23#define CONF1_DS_MASK 0x0000e000
24#define CONF1_DS_BASE 64
25#define CONF1_IA_SHIFT 16 /* I$ associativity */
26#define CONF1_IA_MASK 0x00070000
27#define CONF1_IA_BASE 1
28#define CONF1_IL_SHIFT 19 /* I$ line size */
29#define CONF1_IL_MASK 0x00380000
30#define CONF1_IL_BASE 2
31#define CONF1_IS_SHIFT 22 /* Instruction cache sets/way */
32#define CONF1_IS_MASK 0x01c00000
33#define CONF1_IS_BASE 64
34
35#define Index_Invalidate_I 0x00
36#define Index_Writeback_Inv_D 0x01
37
38    .text
39    LEAF(startup)
40    .set noreorder
41    addi sp, -48
42    sw a0, 16(sp)
43    sw a1, 20(sp)
44    sw a2, 24(sp)
45    sw a3, 28(sp)
46    
47    /* Copy decompressor code to the right place */
48    li t2, BZ_TEXT_START
49    add a0, t2, 0
50    la a1, code_start
51    la a2, code_stop
52$L1:
53    lw t0, 0(a1)
54    sw t0, 0(a0)
55    add a1, 4
56    add a0, 4
57    blt a1, a2, $L1
58    nop
59    
60    /* At this point we need to invalidate dcache and */
61    /* icache before jumping to new code */
62
631: /* Get cache sizes */
64    .set mips32
65    mfc0 s0,C0_CONFIG,1
66    .set mips0
67
68    li s1,CONF1_DL_MASK
69    and s1,s0
70    beq s1,zero,nodc
71    nop
72
73    srl s1,CONF1_DL_SHIFT
74    li t0,CONF1_DL_BASE
75    sll s1,t0,s1 /* s1 has D$ cache line size */
76
77    li s2,CONF1_DA_MASK
78    and s2,s0
79    srl s2,CONF1_DA_SHIFT
80    addiu s2,CONF1_DA_BASE /* s2 now has D$ associativity */
81
82    li t0,CONF1_DS_MASK
83    and t0,s0
84    srl t0,CONF1_DS_SHIFT
85    li s3,CONF1_DS_BASE
86    sll s3,s3,t0 /* s3 has D$ sets per way */
87
88    multu s2,s3 /* sets/way * associativity */
89    mflo t0 /* total cache lines */
90
91    multu s1,t0 /* D$ linesize * lines */
92    mflo s2 /* s2 is now D$ size in bytes */
93
94    /* Initilize the D$: */
95    mtc0 zero,C0_TAGLO
96    mtc0 zero,C0_TAGHI
97
98    li t0,KSEG0 /* Just an address for the first $ line */
99    addu t1,t0,s2 /* + size of cache == end */
100
101    .set mips3
1021: cache Index_Writeback_Inv_D,0(t0)
103    .set mips0
104    bne t0,t1,1b
105    addu t0,s1
106    
107nodc:
108    /* Now we get to do it all again for the I$ */
109    
110    move s3,zero /* just in case there is no icache */
111    move s4,zero
112
113    li t0,CONF1_IL_MASK
114    and t0,s0
115    beq t0,zero,noic
116    nop
117
118    srl t0,CONF1_IL_SHIFT
119    li s3,CONF1_IL_BASE
120    sll s3,t0 /* s3 has I$ cache line size */
121
122    li t0,CONF1_IA_MASK
123    and t0,s0
124    srl t0,CONF1_IA_SHIFT
125    addiu s4,t0,CONF1_IA_BASE /* s4 now has I$ associativity */
126
127    li t0,CONF1_IS_MASK
128    and t0,s0
129    srl t0,CONF1_IS_SHIFT
130    li s5,CONF1_IS_BASE
131    sll s5,t0 /* s5 has I$ sets per way */
132
133    multu s4,s5 /* sets/way * associativity */
134    mflo t0 /* s4 is now total cache lines */
135
136    multu s3,t0 /* I$ linesize * lines */
137    mflo s4 /* s4 is cache size in bytes */
138
139    /* Initilize the I$: */
140    mtc0 zero,C0_TAGLO
141    mtc0 zero,C0_TAGHI
142
143    li t0,KSEG0 /* Just an address for the first $ line */
144    addu t1,t0,s4 /* + size of cache == end */
145
146    .set mips3
1471: cache Index_Invalidate_I,0(t0)
148    .set mips0
149    bne t0,t1,1b
150    addu t0,s3
151
152noic:
153    move a0,s3 /* icache line size */
154    move a1,s4 /* icache size */
155    move a2,s1 /* dcache line size */
156    jal t2
157    move a3,s2 /* dcache size */
158    
159    .set reorder
160    END(startup)
161

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