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// Basic low-level x86 32-bit calls //
// reading and writing ports
.global x86_outb // 8 bit out
.global x86_inb // 8 bit in
.global x86_outw // 16 bit out
.global x86_inw // 16 bit in
.global x86_outl // 32 bit out
.global x86_inl // 32 bit in
// interrupts
.global x86_cli // disable interrupts
.global x86_sti // enable interrupts
// xchg
.global x86_xchg // exchange (for semaphors etc.)
// invlpg
.global x86_invlpg // invalidate translation lookaside buffer (tlb)
// control registers
.global x86_get_cr
.global x86_set_cr
x86_outb:
mov 4(%esp), %edx
mov 8(%esp), %eax
outb %al,%dx
ret
x86_inb:
mov 4(%esp), %edx
inb %dx,%al
ret
x86_outw:
mov 4(%esp), %edx
mov 8(%esp), %eax
outw %ax,%dx
ret
x86_inw:
mov 4(%esp), %edx
inw %dx,%ax
ret
x86_outl:
mov 4(%esp), %edx
mov 8(%esp), %eax
outl %eax,%dx
ret
x86_inl:
mov 4(%esp), %edx
inl %dx,%eax
ret
x86_cli:
cli
ret
x86_sti:
sti
ret
x86_xchg:
// -- uint8_t result;
// --
// -- // The + in "+m" denotes a read-modify-write operand.
// -- asm volatile("lock xchgb %0, %1" :
// -- "+m" (*addr), "=a" (result) :
// -- "1" (val) :
// -- "cc");
// --
// -- return result;
// -- }
ret
x86_get_cr:
mov 4(%esp), %ecx
cmp $0,%ecx
je get_cr0
cmp $2,%ecx
je get_cr2
cmp $3,%ecx
je get_cr3
cmp $4,%ecx
je get_cr4
ret
x86_set_cr:
mov 4(%esp), %ecx
mov 8(%esp), %eax
cmp $0,%ecx
je set_cr0
cmp $2,%ecx
je set_cr2
cmp $3,%ecx
je set_cr3
cmp $4,%ecx
je set_cr4
ret
get_cr0:
mov %cr0,%eax
ret
get_cr2:
mov %cr2,%eax
ret
get_cr3:
mov %cr3,%eax
ret
get_cr4:
mov %cr4,%eax
ret
set_cr0:
mov %eax,%cr0
ret
set_cr2:
mov %eax,%cr2
ret
set_cr3:
mov %eax,%cr3
ret
set_cr4:
mov %eax,%cr4
ret
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