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riscv64: simplify assembly constructs not supported by tcc. 

At the moment tcc does not support assembler instructions
with C expression operands. As a workaround read values
directly from stack.

* lib/linux/riscv64-mes-tcc/_exit.c
* lib/linux/riscv64-mes-tcc/_write.c
* lib/linux/riscv64-mes-tcc/syscall.c
This commit is contained in:
Andrius Štikonas 2023-10-04 23:23:05 +01:00
parent 44de0ec1c4
commit eea9f759ee
3 changed files with 28 additions and 52 deletions
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6
lib/linux/riscv64-mes-tcc/_exit.c
View File

@ -28,12 +28,10 @@
void
_exit (int code)
{
register long __a7 asm ("a7") = SYS_exit;
register long __a0 asm ("a0") = code;
asm volatile (
"addi a7, zero, 93\n\t"
"ld a0, s0, -24\n\t"
"ecall\n\t"
: // no outputs
: "r" (__a0), "r" (__a7)
);
// not reached
_exit (0);

11
lib/linux/riscv64-mes-tcc/_write.c
View File

@ -28,14 +28,11 @@
ssize_t
_write (int filedes, void const *buffer, size_t size)
{
register long __a7 asm ("a7") = (long) SYS_write;
register long __a0 asm ("a0") = (long) filedes;
register long __a1 asm ("a1") = (long) buffer;
register long __a2 asm ("a2") = (long) size;
asm volatile (
"addi a7, zero, 64\n\t"
"ld a0, s0, -24\n\t"
"ld a1, s0, -32\n\t"
"ld a2, s0, -40\n\t"
"ecall\n\t"
: "+r" (__a0)
: "r" (__a7), "r" (__a1), "r" (__a2)
);
return (ssize_t)__a0;
}

63
lib/linux/riscv64-mes-tcc/syscall.c
View File

@ -27,89 +27,70 @@
long
__sys_call (long sys_call)
{
register long __a7 asm ("a7") = sys_call;
register long __a0 asm ("a0");
asm volatile (
asm volatile (
"ld a7, s0, -24\n\t"
"ecall\n\t"
: "=r" (__a0)
: "r" (__a7)
);
return __a0;
}
long
__sys_call1 (long sys_call, long one)
{
register long __a7 asm ("a7") = sys_call;
register long __a0 asm ("a0") = one;
asm volatile (
"ld a7, s0, -24\n\t"
"ld a0, s0, -32\n\t"
"ecall\n\t"
: "+r" (__a0)
: "r" (__a7)
);
return __a0;
}
long
__sys_call2 (long sys_call, long one, long two)
{
register long __a7 asm ("a7") = sys_call;
register long __a0 asm ("a0") = one;
register long __a1 asm ("a1") = two;
asm volatile (
"ld a7, s0, -24\n\t"
"ld a0, s0, -32\n\t"
"ld a1, s0, -40\n\t"
"ecall\n\t"
: "+r" (__a0)
: "r" (__a7), "r" (__a1)
);
return __a0;
}
long
__sys_call3 (long sys_call, long one, long two, long three)
{
register long __a7 asm ("a7") = sys_call;
register long __a0 asm ("a0") = one;
register long __a1 asm ("a1") = two;
register long __a2 asm ("a2") = three;
asm volatile (
"ld a7, s0, -24\n\t"
"ld a0, s0, -32\n\t"
"ld a1, s0, -40\n\t"
"ld a2, s0, -48\n\t"
"ecall\n\t"
: "+r" (__a0)
: "r" (__a7), "r" (__a1), "r" (__a2)
);
return __a0;
}
long
__sys_call4 (long sys_call, long one, long two, long three, long four)
{
register long __a7 asm ("a7") = sys_call;
register long __a0 asm ("a0") = one;
register long __a1 asm ("a1") = two;
register long __a2 asm ("a2") = three;
register long __a3 asm ("a3") = four;
asm volatile (
"ld a7, s0, -24\n\t"
"ld a0, s0, -32\n\t"
"ld a1, s0, -40\n\t"
"ld a2, s0, -48\n\t"
"ld a3, s0, -56\n\t"
"ecall\n\t"
: "+r" (__a0)
: "r" (__a7), "r" (__a1), "r" (__a2), "r" (__a3)
);
return __a0;
}
long
__sys_call5 (long sys_call, long one, long two, long three, long four, long five)
{
register long __a7 asm ("a7") = sys_call;
register long __a0 asm ("a0") = one;
register long __a1 asm ("a1") = two;
register long __a2 asm ("a2") = three;
register long __a3 asm ("a3") = four;
register long __a4 asm ("a4") = five;
asm volatile (
"ld a7, s0, -24\n\t"
"ld a0, s0, -32\n\t"
"ld a1, s0, -40\n\t"
"ld a2, s0, -48\n\t"
"ld a3, s0, -56\n\t"
"ld a4, s0, -64\n\t"
"ecall\n\t"
: "+r" (__a0)
: "r" (__a7), "r" (__a1), "r" (__a2), "r" (__a3), "r" (__a4)
);
return __a0;
}
// *INDENT-ON*