64 lines
1.2 KiB
C
64 lines
1.2 KiB
C
// System call stubs.
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#include <inc/syscall.h>
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#include <inc/lib.h>
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static inline int32_t
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syscall(int num, int check, uint32_t a1, uint32_t a2, uint32_t a3, uint32_t a4, uint32_t a5)
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{
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int32_t ret;
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// Generic system call: pass system call number in AX,
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// up to five parameters in DX, CX, BX, DI, SI.
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// Interrupt kernel with T_SYSCALL.
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//
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// The "volatile" tells the assembler not to optimize
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// this instruction away just because we don't use the
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// return value.
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//
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// The last clause tells the assembler that this can
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// potentially change the condition codes and arbitrary
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// memory locations.
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asm volatile("int %1\n"
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: "=a" (ret)
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: "i" (T_SYSCALL),
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"a" (num),
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"d" (a1),
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"c" (a2),
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"b" (a3),
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"D" (a4),
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"S" (a5)
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: "cc", "memory");
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if(check && ret > 0)
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panic("syscall %d returned %d (> 0)", num, ret);
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return ret;
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}
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void
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sys_cputs(const char *s, size_t len)
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{
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syscall(SYS_cputs, 0, (uint32_t)s, len, 0, 0, 0);
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}
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int
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sys_cgetc(void)
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{
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return syscall(SYS_cgetc, 0, 0, 0, 0, 0, 0);
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}
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int
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sys_env_destroy(envid_t envid)
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{
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return syscall(SYS_env_destroy, 1, envid, 0, 0, 0, 0);
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}
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envid_t
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sys_getenvid(void)
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{
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return syscall(SYS_getenvid, 0, 0, 0, 0, 0, 0);
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}
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