mirror of
https://github.com/RaySollium99/picodrive.git
synced 2025-10-27 21:48:50 +01:00
1c88b865ce
git-svn-id: file:///home/notaz/opt/svn/PicoDrive@186 be3aeb3a-fb24-0410-a615-afba39da0efa
119 lines
2.3 KiB
C
119 lines
2.3 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <time.h>
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static FILE *f;
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#define bswap16(x) (x=(unsigned short)((x<<8)|(x>>8)))
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#define bswap32(x) (x=((x<<24)|((x<<8)&0xff0000)|((x>>8)&0x00ff00)|((unsigned)x>>24)))
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static void write_op(unsigned short op, unsigned short word0, unsigned short word1, unsigned short word2)
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{
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bswap16(op);
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bswap16(word0);
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bswap16(word1);
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bswap16(word2);
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fwrite(&op, 1, sizeof(op), f);
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fwrite(&word0, 1, sizeof(word0), f);
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fwrite(&word1, 1, sizeof(word1), f);
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fwrite(&word2, 1, sizeof(word2), f);
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}
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static void write32(unsigned int a)
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{
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bswap32(a);
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fwrite(&a, 1, sizeof(a), f);
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}
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static int op_check(unsigned short op)
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{
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if ((op&0xf000) == 0x6000) return 0; // Bxx
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if ((op&0xf0f8) == 0x50c8) return 0; // DBxx
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if ((op&0xff80) == 0x4e80) return 0; // Jsr
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if ((op&0xf000) == 0xa000) return 0; // a-line
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if ((op&0xf000) == 0xf000) return 0; // f-line
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if ((op&0xfff8)==0x4e70&&op!=0x4e71&&op!=0x4e76) return 0; // reset, rte, rts
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if ((op&0x3f) >= 0x28) op = (op&~0x3f) | (rand() % 0x28);
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return 1;
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}
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static unsigned short safe_rand(void)
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{
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unsigned short op;
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/* avoid branch opcodes */
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do
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{
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op = rand();
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}
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while (!op_check(op));
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return op;
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}
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int main()
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{
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int i, op;
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srand(time(0));
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f = fopen("test_misc2.bin", "wb");
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if (!f) return 1;
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write32(0x00ff8000); // stack
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write32(0x300); // IP
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for (i=0x100/4-2; i; i--)
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{
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write32(0x200+i*4); // exception vectors
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}
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for (i=0x100/4; i; i--)
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{
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write32(0); // pad
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}
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for (i=0x100/4; i; i--)
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{
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write32(0x4e734e73); // fill with rte instructions
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}
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for (op = 0; op < 0x10000; op++)
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{
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if ((op&0xf000) == 0x6000) // Bxx
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{
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if ((op&0x00ff) == 0)
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write_op(op, 6, 0, 0);
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}
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else if ((op&0xf0f8)==0x50c8) // DBxx
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{
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write_op(op, 6, 0, 0);
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}
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else if ((op&0xff80)==0x4e80) // Jsr
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{
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int addr = 0x300 + op*8 + 8;
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if ((op&0x3f) == 0x39)
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write_op(op, addr >> 16, addr & 0xffff, 0);
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}
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else if ((op&0xf000)==0xa000 || (op&0xf000)==0xf000) // a-line, f-line
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{
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if (op != 0xa000 && op != 0xf000) continue;
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}
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else if ((op&0xfff8)==0x4e70&&op!=0x4e71&&op!=0x4e76); // rte, rts, stop, reset
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else
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{
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write_op(op, safe_rand(), safe_rand(), safe_rand());
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}
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}
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// jump to the beginning
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write_op(0x4ef8, 0x300, 0x4ef8, 0x300);
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write_op(0x4ef8, 0x300, 0x4ef8, 0x300);
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fclose(f);
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return 0;
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}
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