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// Routines to let C code use special x86 instructions.
#ifndef __ASSEMBLER__
static inline uchar
inb(ushort port)
{
uchar data;
asm volatile("in %1,%0" : "=a" (data) : "d" (port));
return data;
}
static inline void
insl(int port, void *addr, int cnt)
{
asm volatile("cld; rep insl" :
"=D" (addr), "=c" (cnt) :
"d" (port), "0" (addr), "1" (cnt) :
"memory", "cc");
}
static inline void
outb(ushort port, uchar data)
{
asm volatile("out %0,%1" : : "a" (data), "d" (port));
}
static inline void
outw(ushort port, ushort data)
{
asm volatile("out %0,%1" : : "a" (data), "d" (port));
}
static inline void
outsl(int port, const void *addr, int cnt)
{
asm volatile("cld; rep outsl" :
"=S" (addr), "=c" (cnt) :
"d" (port), "0" (addr), "1" (cnt) :
"cc");
}
static inline void
stosb(void *addr, int data, int cnt)
{
asm volatile("cld; rep stosb" :
"=D" (addr), "=c" (cnt) :
"0" (addr), "1" (cnt), "a" (data) :
"memory", "cc");
}
static inline void
stosl(void *addr, int data, int cnt)
{
asm volatile("cld; rep stosl" :
"=D" (addr), "=c" (cnt) :
"0" (addr), "1" (cnt), "a" (data) :
"memory", "cc");
}
static inline void
lgdt(void *p)
{
asm volatile("lgdt (%0)" : : "r" (p) : "memory");
}
static inline void
lidt(void *p)
{
asm volatile("lidt (%0)" : : "r" (p) : "memory");
}
static inline void
ltr(ushort sel)
{
asm volatile("ltr %0" : : "r" (sel));
}
static inline uint64
readeflags(void)
{
uint64 eflags;
asm volatile("pushf; pop %0" : "=r" (eflags));
return eflags;
}
static inline void
loadgs(ushort v)
{
asm volatile("movw %0, %%gs" : : "r" (v));
}
static inline void
cli(void)
{
asm volatile("cli");
}
static inline void
sti(void)
{
asm volatile("sti");
}
static inline uint
xchg(volatile uint *addr, uint newval)
{
uint result;
// The + in "+m" denotes a read-modify-write operand.
asm volatile("lock; xchgl %0, %1" :
"+m" (*addr), "=a" (result) :
"1" (newval) :
"cc");
return result;
}
static inline uint
rcr2(void)
{
uint64 val;
asm volatile("mov %%cr2,%0" : "=r" (val));
return val;
}
static inline void
lcr3(uint64 val)
{
asm volatile("mov %0,%%cr3" : : "r" (val));
}
static inline void
writegs(uint16 v)
{
__asm volatile("movw %0, %%gs" : : "r" (v));
}
//PAGEBREAK: 36
// Layout of the trap frame built on the stack by the
// hardware and by trapasm.S, and passed to trap().
struct trapframe {
uint64 rax;
uint64 rbx;
uint64 rcx;
uint64 rdx;
uint64 rbp;
uint64 rsi;
uint64 rdi;
uint64 r8;
uint64 r9;
uint64 r10;
uint64 r11;
uint64 r12;
uint64 r13;
uint64 r14;
uint64 r15;
uint64 trapno;
uint64 err;
uint64 rip;
uint16 cs;
uint16 padding[3];
uint64 rflags;
uint64 rsp;
uint64 ss;
}__attribute__((packed));
struct sysframe {
// arguments
uint64 rdi;
uint64 rsi;
uint64 rdx;
uint64 r10;
uint64 r8;
uint64 r9;
// callee-saved registers
uint64 r15;
uint64 r14;
uint64 r13;
uint64 r12;
uint64 rbx;
uint64 rbp;
// return value
uint64 rax;
// syscall registers
uint64 r11; // eflags
uint64 rcx; // rip
uint64 rsp;
}__attribute__((packed));
#endif
#define TF_CS 144 // offset in trapframe for saved cs
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