diff options
Diffstat (limited to 'target/image/generic/lzma-loader/src/start.S')
| -rw-r--r-- | target/image/generic/lzma-loader/src/start.S | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/target/image/generic/lzma-loader/src/start.S b/target/image/generic/lzma-loader/src/start.S new file mode 100644 index 0000000..9a85c4c --- /dev/null +++ b/target/image/generic/lzma-loader/src/start.S @@ -0,0 +1,160 @@ +#include <asm/asm.h> +#include <asm/regdef.h> + +#define KSEG0 0x80000000 + +#define C0_CONFIG $16 +#define C0_TAGLO $28 +#define C0_TAGHI $29 + +#define CONF1_DA_SHIFT 7 /* D$ associativity */ +#define CONF1_DA_MASK 0x00000380 +#define CONF1_DA_BASE 1 +#define CONF1_DL_SHIFT 10 /* D$ line size */ +#define CONF1_DL_MASK 0x00001c00 +#define CONF1_DL_BASE 2 +#define CONF1_DS_SHIFT 13 /* D$ sets/way */ +#define CONF1_DS_MASK 0x0000e000 +#define CONF1_DS_BASE 64 +#define CONF1_IA_SHIFT 16 /* I$ associativity */ +#define CONF1_IA_MASK 0x00070000 +#define CONF1_IA_BASE 1 +#define CONF1_IL_SHIFT 19 /* I$ line size */ +#define CONF1_IL_MASK 0x00380000 +#define CONF1_IL_BASE 2 +#define CONF1_IS_SHIFT 22 /* Instruction cache sets/way */ +#define CONF1_IS_MASK 0x01c00000 +#define CONF1_IS_BASE 64 + +#define Index_Invalidate_I 0x00 +#define Index_Writeback_Inv_D 0x01 + +LEAF(_start) + + .set mips32 + .set noreorder + + /* save argument registers */ + move t4, a0 + move t5, a1 + move t6, a2 + move t7, a3 + + /* set up stack */ + li sp, 0xa0000000 + RAMSIZE - 16 + +#ifdef IMAGE_COPY + /* Copy decompressor code to the right place */ + li t2, LOADADDR + add a0, t2, 0 + la a1, code_start + la a2, code_stop +$L1: + lw t0, 0(a1) + sw t0, 0(a0) + add a1, 4 + add a0, 4 + blt a1, a2, $L1 + nop +#endif + + /* At this point we need to invalidate dcache and */ + /* icache before jumping to new code */ + +1: /* Get cache sizes */ + mfc0 s0,C0_CONFIG,1 + + li s1,CONF1_DL_MASK + and s1,s0 + beq s1,zero,nodc + nop + + srl s1,CONF1_DL_SHIFT + li t0,CONF1_DL_BASE + sll s1,t0,s1 /* s1 has D$ cache line size */ + + li s2,CONF1_DA_MASK + and s2,s0 + srl s2,CONF1_DA_SHIFT + addiu s2,CONF1_DA_BASE /* s2 now has D$ associativity */ + + li t0,CONF1_DS_MASK + and t0,s0 + srl t0,CONF1_DS_SHIFT + li s3,CONF1_DS_BASE + sll s3,s3,t0 /* s3 has D$ sets per way */ + + multu s2,s3 /* sets/way * associativity */ + mflo t0 /* total cache lines */ + + multu s1,t0 /* D$ linesize * lines */ + mflo s2 /* s2 is now D$ size in bytes */ + + /* Initilize the D$: */ + mtc0 zero,C0_TAGLO + mtc0 zero,C0_TAGHI + + li t0,KSEG0 /* Just an address for the first $ line */ + addu t1,t0,s2 /* + size of cache == end */ + +1: cache Index_Writeback_Inv_D,0(t0) + bne t0,t1,1b + addu t0,s1 + +nodc: + /* Now we get to do it all again for the I$ */ + + move s3,zero /* just in case there is no icache */ + move s4,zero + + li t0,CONF1_IL_MASK + and t0,s0 + beq t0,zero,noic + nop + + srl t0,CONF1_IL_SHIFT + li s3,CONF1_IL_BASE + sll s3,t0 /* s3 has I$ cache line size */ + + li t0,CONF1_IA_MASK + and t0,s0 + srl t0,CONF1_IA_SHIFT + addiu s4,t0,CONF1_IA_BASE /* s4 now has I$ associativity */ + + li t0,CONF1_IS_MASK + and t0,s0 + srl t0,CONF1_IS_SHIFT + li s5,CONF1_IS_BASE + sll s5,t0 /* s5 has I$ sets per way */ + + multu s4,s5 /* sets/way * associativity */ + mflo t0 /* s4 is now total cache lines */ + + multu s3,t0 /* I$ linesize * lines */ + mflo s4 /* s4 is cache size in bytes */ + + /* Initilize the I$: */ + mtc0 zero,C0_TAGLO + mtc0 zero,C0_TAGHI + + li t0,KSEG0 /* Just an address for the first $ line */ + addu t1,t0,s4 /* + size of cache == end */ + +1: cache Index_Invalidate_I,0(t0) + bne t0,t1,1b + addu t0,s3 +noic: + /* jump to main */ + move a0,s3 /* icache line size */ + move a1,s4 /* icache size */ + move a2,s1 /* dcache line size */ +#ifdef IMAGE_COPY + jal t2 +#else + jal entry +#endif + move a3,s2 /* dcache size */ + + .set reorder +END(_start) + |