124 lines
3.5 KiB
NASM
124 lines
3.5 KiB
NASM
;=----------------------------------------------------------------------------=;
|
|
; OS on Kaleid ;
|
|
; ;
|
|
; Desc: System call & userspace related functions ;
|
|
; ;
|
|
; ;
|
|
; Copyright © 2018-2021 The OS/K Team ;
|
|
; ;
|
|
; This file is part of OS/K. ;
|
|
; ;
|
|
; OS/K is free software: you can redistribute it and/or modify ;
|
|
; it under the terms of the GNU General Public License as published by ;
|
|
; the Free Software Foundation, either version 3 of the License, or ;
|
|
; (at your option) any later version. ;
|
|
; ;
|
|
; OS/K is distributed in the hope that it will be useful, ;
|
|
; but WITHOUT ANY WARRANTY; without even the implied warranty of ;
|
|
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;
|
|
; GNU General Public License for more details. ;
|
|
; ;
|
|
; You should have received a copy of the GNU General Public License ;
|
|
; along with OS/K. If not, see <https://www.gnu.org/licenses/>. ;
|
|
;=----------------------------------------------------------------------------=;
|
|
|
|
[BITS 64]
|
|
|
|
%include "kaleid/kernel/ke/cpuf.inc"
|
|
|
|
global KeJumpToUserspace
|
|
global KeSyscall
|
|
global syscallPreHandler
|
|
extern _KeSyscallHandler
|
|
|
|
|
|
;;
|
|
;; System call pre-handler
|
|
;;
|
|
syscallPreHandler:
|
|
push rax ; rax
|
|
push rbx
|
|
push rcx
|
|
push 0 ; rdx
|
|
push 0 ; rsi
|
|
push 0 ; rdi
|
|
push rbp
|
|
push r8
|
|
push r9
|
|
push 0 ; r10
|
|
push r11
|
|
push r12
|
|
push r13
|
|
push r14
|
|
push r15
|
|
mov rax, cr8
|
|
push rax
|
|
mov rax, cr4
|
|
push rax
|
|
mov rax, cr3
|
|
push rax
|
|
mov rax, cr2
|
|
push rax
|
|
mov rax, cr0
|
|
push rax
|
|
mov rcx, 0xC0000080
|
|
rdmsr
|
|
push rax
|
|
|
|
; Call the C routine to dispatch interrupts
|
|
cld ; DF must be cleared by the caller
|
|
mov r8, rsp ; First argument points to the processor state
|
|
mov rbp, 0 ; Terminate stack traces here
|
|
|
|
call _KeSyscallHandler
|
|
|
|
; pop the control registers
|
|
add rsp, 48
|
|
; pop registers except return value
|
|
pop r15
|
|
pop r14
|
|
pop r13
|
|
pop r12
|
|
pop r11
|
|
pop r10
|
|
pop r9
|
|
pop r8
|
|
pop rbp
|
|
pop rdi
|
|
pop rsi
|
|
pop rdx
|
|
pop rcx
|
|
pop rbx
|
|
; pop rax without overwriting
|
|
add rsp, 8
|
|
; pop the error code, interrupt id
|
|
add rsp, 16
|
|
|
|
iretq
|
|
|
|
;;
|
|
;; To get ring3 code running
|
|
;;
|
|
KeJumpToUserspace:
|
|
|
|
; rdi = user args
|
|
; rsi = entry point in user space
|
|
; rdx = user space stack
|
|
|
|
; Build a fake iret frame
|
|
push QWORD 0x23 ; Selector 0x20 (User Data) + RPL 3
|
|
push rdx ; User space stack
|
|
push QWORD 0x202 ; rflags = interrupt enable + reserved bit
|
|
push QWORD 0x1B ; Selector 0x18 (User Code) + RPL 3
|
|
push rsi ; Entry point in user space
|
|
|
|
iretq
|
|
|
|
|
|
;;
|
|
;; Syscall trigger
|
|
;;
|
|
KeSyscall:
|
|
int 0x80
|
|
ret
|