67 lines
1.6 KiB
C
67 lines
1.6 KiB
C
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extern int main(int argc, char **argv, char **envp);
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extern int brk (void *value);
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extern char bss_start;
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extern char end;
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char *__env[1] = {0};
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char **environ = __env;
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#define ENABLE_TRACE_MASK 1
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__inline static void
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enable_tracing (void)
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{
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register int mask = ENABLE_TRACE_MASK;
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__asm__ volatile ("modpc %0,%0,%0"
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:
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: "d" (mask));
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}
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#define STACK_ALIGN 64
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__inline static void
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set_stack (void* ptr)
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{
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ptr = (void *)(((int)ptr + STACK_ALIGN - 1) & ~(STACK_ALIGN - 1));
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/* SP must be 64 bytes larger than FP at start. */
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__asm__ volatile ("mov %0,sp"
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:
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: "d" (ptr+STACK_ALIGN));
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__asm__ volatile ("mov %0,fp"
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:
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: "d" (ptr));
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}
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__inline static void
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init_Cregs (void)
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{
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/* set register values gcc like */
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register unsigned int mask0=0x3b001000;
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register unsigned int mask1=0x00009107;
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__asm__ volatile ("mov %0,g14"
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: /* no output */
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: "I" (0)); /* gnu structure pointer */
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__asm__ volatile ("modac %1,%0,%0"
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: /* no output */
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: "d" (mask0),
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"d" (mask1)); /* fpu control kb */
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}
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void
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_start(void)
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{
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char *p;
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enable_tracing ();
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set_stack (&end);
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init_Cregs ();
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/* The stack grows upwards, so this makes the heap start after a 256K
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stack area. PlumHall known to fail with less than 73K of stack. */
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brk (&end+0x40000);
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/* clear bss */
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memset (&bss_start, 0, &end - &bss_start);
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main(0, 0, 0);
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exit(0);
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}
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