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path: root/target/image/generic/lzma-loader/src/start.S
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-rw-r--r--target/image/generic/lzma-loader/src/start.S160
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)
+