68 lines
1.5 KiB
C
68 lines
1.5 KiB
C
#if defined(__x86_64__)
|
|
#include "../int.h"
|
|
|
|
#define SYS_EXIT 60
|
|
void exit(int8_t status) {
|
|
asm volatile(
|
|
"syscall"
|
|
:
|
|
: "a"(SYS_EXIT), "D"(status)
|
|
:
|
|
);
|
|
for(;;);
|
|
}
|
|
|
|
#define SYS_WRITE 1
|
|
intptr_t write(int32_t fd, const void* buf, intptr_t size) {
|
|
intptr_t n_written = 0;
|
|
asm volatile (
|
|
"syscall\n"
|
|
"movq %0, %%rax\n"
|
|
: "=r"(n_written)
|
|
: "a"(SYS_WRITE), "D"(fd), "S"(buf), "d"(size) // RDI, RSI, RDX are used in x86-64 for write args
|
|
: "rcx", "r11"
|
|
);
|
|
return n_written;
|
|
}
|
|
|
|
#define SYS_READ 0
|
|
intptr_t read(int32_t fd, const void* buf, intptr_t size) {
|
|
intptr_t n_read = 0;
|
|
asm volatile (
|
|
"syscall\n"
|
|
"movq %0, %%rax\n"
|
|
: "=r"(n_read)
|
|
: "a"(SYS_READ), "D"(fd), "S"(buf), "d"(size) // RDI, RSI, RDX are used in x86-64 for write args
|
|
: "rcx", "r11", "memory"
|
|
);
|
|
return n_read;
|
|
}
|
|
|
|
#define SYS_FORK 57
|
|
uint32_t fork() {
|
|
uint64_t rtn;
|
|
asm volatile(
|
|
"syscall\n" // syscall
|
|
"movq %0, %%rax\n" // save return value
|
|
: "=r"(rtn)
|
|
: "a"(SYS_FORK)
|
|
:
|
|
);
|
|
return (uint32_t)rtn;
|
|
}
|
|
|
|
#define SYS_OPENAT 257
|
|
int32_t openat(int32_t fd, const char* filename, uint32_t flags, uint32_t mode) {
|
|
int32_t file;
|
|
asm volatile (
|
|
"mov %5, %%r10\n"
|
|
"syscall\n"
|
|
: "=a"(file)
|
|
: "a"(SYS_OPENAT), "D"(fd), "S"(filename), "d"(flags), "r"((uint64_t)mode) // RDI, RSI, RDX are used in x86-64 for write args
|
|
: "rcx", "r10", "r11"
|
|
);
|
|
return file;
|
|
}
|
|
|
|
#endif /* ifdef __x86_64__ */
|