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This commit is contained in:
Justin C. Miller
2018-05-20 01:03:04 -07:00
parent 814d6f1de6
commit 24ccf65aba
4 changed files with 158 additions and 26 deletions
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97
src/kernel/interrupts.s
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@@ -150,3 +150,100 @@ irq_handler_prelude:
section .isrs
%include "interrupt_isrs.inc"
extern syscall_handler
syscall_handler_prelude:
push 0 ; ss, doesn't matter here
push rsp
pushf
push 0 ; cs, doesn't matter here
push rcx ; user rip
push 0 ; bogus interrupt
push 0 ; bogus errorcode
push_all_and_segments
call syscall_handler
pop_all_and_segments
add rsp, 16 ; ignore bogus interrupt / error
pop rcx ; user rip
add rsp, 32 ; ignore cs, flags, rsp, ss
o64 sysret
global syscall_enable
syscall_enable:
; IA32_EFER - set bit 0, syscall enable
mov rcx, 0xc0000080
rdmsr
or rax, 0x1
wrmsr
; IA32_STAR - cs for syscall
mov rcx, 0xc0000081
mov rax, 0 ; not used
mov rdx, 0x00180008 ; GDT:3 (user code), GDT:1 (kernel code)
wrmsr
; IA32_LSTAR - RIP for syscall
mov rcx, 0xc0000082
lea rax, [rel syscall_handler_prelude]
mov rdx, rax
shr rdx, 32
wrmsr
; IA32_FMASK - FLAGS mask inside syscall
mov rcx, 0xc0000084
mov rax, 0x200
mov rdx, 0
wrmsr
ret
global taskA
taskA:
push rbp
mov rbp, rsp
push 0x123456789abcdef0
push 0x0fedcba987654321
.loop:
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
syscall
nop
nop
nop
nop
nop
nop
jmp .loop