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mescc: Mes C Library: ARM: _start: Inline fake asm.

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* lib/linux/arm-mes-gcc/crt1.c (_start): Use inline fake asm.
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Jan (janneke) Nieuwenhuizen 2020-12-07 07:16:14 +01:00
parent 9711ed70ec
commit 4e7a6057aa
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1 changed files with 78 additions and 43 deletions
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121
lib/linux/arm-mes-gcc/crt1.c
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@ -22,11 +22,11 @@
#include <mes/lib-mini.h>
//int main (int argc, char *argv[], char *envp[]);
#if !__TINYC__
/* Note: GCC automatically emits a preable in order to set up the
frame pointer: "push {fp}" "add fp, sp, 0"
*/
// *INDENT-OFF*
#if !__TINYC__
void
_start ()
{
@ -76,46 +76,81 @@ _start ()
);
}
#else //__TINYC__
__asm__ (".global _start\n");
__asm__ ("_start:\n");
__asm__ (".int 0xe52db004\n"); //push {fp} ; (str fp, [sp, #-4]!)
__asm__ (".int 0xe28db000\n"); //add fp, sp, #0
__asm__ (".int 0xe3a00000\n"); //mov r0, #0
__asm__ (".int 0xe1a02000\n"); //mov r2, r0
__asm__ (".int 0xe3003000\n"); //movw r3, #0
__asm__ (".int 0xe3403000\n"); //movt r3, #0
__asm__ (".int 0xe5832000\n"); //str r2, [r3]
__asm__ (".int 0xe3a00001\n"); //mov r0, #1
__asm__ (".int 0xe1a02000\n"); //mov r2, r0
__asm__ (".int 0xe3003000\n"); //movw r3, #0
__asm__ (".int 0xe3403000\n"); //movt r3, #0
__asm__ (".int 0xe5832000\n"); //str r2, [r3]
__asm__ (".int 0xe3a00002\n"); //mov r0, #2
__asm__ (".int 0xe1a02000\n"); //mov r2, r0
__asm__ (".int 0xe3003000\n"); //movw r3, #0
__asm__ (".int 0xe3403000\n"); //movt r3, #0
__asm__ (".int 0xe5832000\n"); //str r2, [r3]
__asm__ (".int 0xe59b0004\n"); //ldr r0, [fp, #4]
__asm__ (".int 0xe28b1008\n"); //add r1, fp, #8
__asm__ (".int 0xe2802001\n"); //add r2, r0, #1
__asm__ (".int 0xe1a02102\n"); //lsl r2, r2, #2
__asm__ (".int 0xe0822001\n"); //add r2, r2, r1
__asm__ (".int 0xe52d2004\n"); //push {r2} ; (str r2, [sp, #-4]!)
__asm__ (".int 0xe52d1004\n"); //push {r1} ; (str r1, [sp, #-4]!)
__asm__ (".int 0xe52d0004\n"); //push {r0} ; (str r0, [sp, #-4]!)
__asm__ (".int 0xe1a02002\n"); //mov r2, r2
__asm__ (".int 0xe3003000\n"); //movw r3, #0
__asm__ (".int 0xe3403000\n"); //movt r3, #0
__asm__ (".int 0xe5832000\n"); //str r2, [r3]
__asm__ (".int 0xe59d0000\n"); //ldr r0, [sp]
__asm__ (".int 0xe59d1004\n"); //ldr r1, [sp, #4]
__asm__ (".int 0xe59d2008\n"); //ldr r2, [sp, #8]
__asm__ (".int 0xebfffffe\n"); //bl 0 <main>
__asm__ (".int 0xe3a07001\n"); //mov r7, #1
__asm__ (".int 0xef000000\n"); //svc 0x00000000
__asm__ (".int 0xe320f003\n"); //wfi
__asm__ (".int 0xe320f000\n"); //nop {0}
__asm__ (".int 0xe28bd000\n"); //add sp, fp, #0
__asm__ (".int 0xe49db004\n"); //pop {fp} ; (ldr fp, [sp], #4)
__asm__ (".int 0xe12fff1e\n"); //bx lr
void
_start ()
{
#if 0
__asm__ (".int 0xe320f000\n"); //nop {0}
__asm__ (".int 0xe320f000\n"); //nop {0}
#endif
int *in = &__stdin;
int *out = &__stdout;
int *err = &__stderr;
char ***env = &environ;
#if 0
__asm__ (".int 0xe320f000\n"); //nop {0}
__asm__ (".int 0xe320f000\n"); //nop {0}
__asm__ (".int 0xe320f000\n"); //nop {0}
*in = 0x22;
__asm__ (".int 0xe320f000\n"); //nop {0}
*out = 0x33;
__asm__ (".int 0xe320f000\n"); //nop {0}
*err = 0x44;
__asm__ (".int 0xe320f000\n"); //nop {0}
*env = 0x55;
__asm__ (".int 0xe320f000\n"); //nop {0}
#endif
/* environ = argv + argc + 1 */
__asm__ (".int 0xe59b000c\n"); //ldr r0, [fp, #12]
__asm__ (".int 0xe28b1010\n"); //add r1, fp, #16
__asm__ (".int 0xe2802001\n"); //add r2, r0, #1
__asm__ (".int 0xe1a02102\n"); //lsl r2, r2, #2
__asm__ (".int 0xe0822001\n"); //add r2, r2, r1
// setup argc, argv, envp parameters on stack
__asm__ (".int 0xe52d2004\n"); //push {r2} ; (str r2, [sp, #-4]!)
__asm__ (".int 0xe52d1004\n"); //push {r1} ; (str r1, [sp, #-4]!)
__asm__ (".int 0xe52d0004\n"); //push {r0} ; (str r0, [sp, #-4]!)
__asm__ (".int 0xe1a02002\n"); //mov r2, r2
// *in = 0;
__asm__ (".int 0xe3a01000\n"); //mov r1, #0
__asm__ (".int 0xe51b0004\n"); //ldr r0, [fp, #-4]
__asm__ (".int 0xe5801000\n"); //str r1, [r0]
__asm__ (".int 0xe320f000\n"); //nop {0}
// *out = 1;
__asm__ (".int 0xe3a01001\n"); //mov r1, #1
__asm__ (".int 0xe51b0008\n"); //ldr r0, [fp, #-8]
__asm__ (".int 0xe5801000\n"); //str r1, [r0]
__asm__ (".int 0xe320f000\n"); //nop {0}
// *err = 2;
__asm__ (".int 0xe3a01002\n"); //mov r1, #2
__asm__ (".int 0xe51b000c\n"); //ldr r0, [fp, #-12]
__asm__ (".int 0xe5801000\n"); //str r1, [r0]
__asm__ (".int 0xe320f000\n"); //nop {0}
// *env = [sp, #8]
__asm__ (".int 0xe59d1008\n"); //ldr r1, [sp, #8]
__asm__ (".int 0xe51b0010\n"); //ldr r0, [fp, #-16]
__asm__ (".int 0xe5801000\n"); //str r1, [r0]
__asm__ (".int 0xe320f000\n"); //nop {0}
// setup argc, argv, envp parameters in registers
__asm__ (".int 0xe59d0000\n"); //ldr r0, [sp]
__asm__ (".int 0xe59d1004\n"); //ldr r1, [sp, #4]
__asm__ (".int 0xe59d2008\n"); //ldr r2, [sp, #8]
main ();
__asm__ (".int 0xe3a07001\n"); //mov r7, #1
__asm__ (".int 0xef000000\n"); //svc 0x00000000
__asm__ (".int 0xe320f003\n"); //wfi
__asm__ (".int 0xe320f000\n"); //nop {0}
}
#endif //__TINYC__