prepare for the transition to linux 2.6.22 - make it possible to override the kernel...
[openwrt.git] / target / linux / brcm63xx-2.6 / 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
42 /* Copy decompressor code to the right place */
43 li t2, BZ_TEXT_START
44 add a0, t2, 0
45 la a1, code_start
46 la a2, code_stop
47 $L1:
48 lw t0, 0(a1)
49 sw t0, 0(a0)
50 add a1, 4
51 add a0, 4
52 blt a1, a2, $L1
53 nop
54
55 /* At this point we need to invalidate dcache and */
56 /* icache before jumping to new code */
57
58 1: /* Get cache sizes */
59 .set mips32
60 mfc0 s0,C0_CONFIG,1
61 .set mips0
62
63 li s1,CONF1_DL_MASK
64 and s1,s0
65 beq s1,zero,nodc
66 nop
67
68 srl s1,CONF1_DL_SHIFT
69 li t0,CONF1_DL_BASE
70 sll s1,t0,s1 /* s1 has D$ cache line size */
71
72 li s2,CONF1_DA_MASK
73 and s2,s0
74 srl s2,CONF1_DA_SHIFT
75 addiu s2,CONF1_DA_BASE /* s2 now has D$ associativity */
76
77 li t0,CONF1_DS_MASK
78 and t0,s0
79 srl t0,CONF1_DS_SHIFT
80 li s3,CONF1_DS_BASE
81 sll s3,s3,t0 /* s3 has D$ sets per way */
82
83 multu s2,s3 /* sets/way * associativity */
84 mflo t0 /* total cache lines */
85
86 multu s1,t0 /* D$ linesize * lines */
87 mflo s2 /* s2 is now D$ size in bytes */
88
89 /* Initilize the D$: */
90 mtc0 zero,C0_TAGLO
91 mtc0 zero,C0_TAGHI
92
93 li t0,KSEG0 /* Just an address for the first $ line */
94 addu t1,t0,s2 /* + size of cache == end */
95
96 .set mips3
97 1: cache Index_Writeback_Inv_D,0(t0)
98 .set mips0
99 bne t0,t1,1b
100 addu t0,s1
101
102 nodc:
103 /* Now we get to do it all again for the I$ */
104
105 move s3,zero /* just in case there is no icache */
106 move s4,zero
107
108 li t0,CONF1_IL_MASK
109 and t0,s0
110 beq t0,zero,noic
111 nop
112
113 srl t0,CONF1_IL_SHIFT
114 li s3,CONF1_IL_BASE
115 sll s3,t0 /* s3 has I$ cache line size */
116
117 li t0,CONF1_IA_MASK
118 and t0,s0
119 srl t0,CONF1_IA_SHIFT
120 addiu s4,t0,CONF1_IA_BASE /* s4 now has I$ associativity */
121
122 li t0,CONF1_IS_MASK
123 and t0,s0
124 srl t0,CONF1_IS_SHIFT
125 li s5,CONF1_IS_BASE
126 sll s5,t0 /* s5 has I$ sets per way */
127
128 multu s4,s5 /* sets/way * associativity */
129 mflo t0 /* s4 is now total cache lines */
130
131 multu s3,t0 /* I$ linesize * lines */
132 mflo s4 /* s4 is cache size in bytes */
133
134 /* Initilize the I$: */
135 mtc0 zero,C0_TAGLO
136 mtc0 zero,C0_TAGHI
137
138 li t0,KSEG0 /* Just an address for the first $ line */
139 addu t1,t0,s4 /* + size of cache == end */
140
141 .set mips3
142 1: cache Index_Invalidate_I,0(t0)
143 .set mips0
144 bne t0,t1,1b
145 addu t0,s3
146
147 noic:
148 move a0,s3 /* icache line size */
149 move a1,s4 /* icache size */
150 move a2,s1 /* dcache line size */
151 jal t2
152 move a3,s2 /* dcache size */
153
154 .set reorder
155 END(startup)
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