51 lines
2.4 KiB
NASM
51 lines
2.4 KiB
NASM
;=----------------------------------------------------------------------------=;
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; OS on Kaleid ;
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; ;
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; Desc: System call & userspace related functions ;
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; ;
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; ;
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; Copyright © 2018-2021 The OS/K Team ;
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; ;
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; This file is part of OS/K. ;
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; ;
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; OS/K is free software: you can redistribute it and/or modify ;
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; it under the terms of the GNU General Public License as published by ;
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; the Free Software Foundation, either version 3 of the License, or ;
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; (at your option) any later version. ;
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; ;
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; OS/K is distributed in the hope that it will be useful, ;
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; but WITHOUT ANY WARRANTY; without even the implied warranty of ;
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; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;
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; GNU General Public License for more details. ;
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; ;
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; You should have received a copy of the GNU General Public License ;
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; along with OS/K. If not, see <https://www.gnu.org/licenses/>. ;
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;=----------------------------------------------------------------------------=;
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[BITS 64]
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%include "kaleid/kernel/ke/cpuf.inc"
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global KeJumpToUserspace
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KeJumpToUserspace:
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# rdi = user args
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# rsi = entry point in user space
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# rdx = user space stack
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mov rax, 0x1b ; Selector 0x18 (User Data) + RPL 3
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mov ds, ax
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mov es, ax
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# Build a fake iret frame
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push rax # Selector 0x18 (User Data) + RPL 3
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push rdx # User space stack
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push 0x202 # rflags = interrupt enable + reserved bit
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push 0x23 # Selector 0x20 (User Code) + RPL 3
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push rsi # Entry point in user space
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xor rax, rax
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iretq
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