1/*
2 * Copyright (c) 2018 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files
6 * (the "Software"), to deal in the Software without restriction,
7 * including without limitation the rights to use, copy, modify, merge,
8 * publish, distribute, sublicense, and/or sell copies of the Software,
9 * and to permit persons to whom the Software is furnished to do so,
10 * subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23
24#include <asm.h>
25
26#define SYSCALL_ENTRY_SIZE 0x04
27.global _current_stack
28
29FUNCTION (x86_syscall)
30        #copy stack from uthread
31        mov $_current_stack,%esp
32        mov (%esp),%esp
33        sti
34        push %ebx /* Ring 3 return address */
35        push %ebp /* Ring 3 esp */
36
37        push %ecx
38        push %edx
39        push %esi
40        push %edi
41
42        /* syscall table is long. Multiplocation to find offset */
43        mov $SYSCALL_ENTRY_SIZE, %ecx
44        mul %ecx  /* Result is stored in eax */
45        mov $syscall_table, %edx
46        add %edx, %eax
47        call (%eax)
48
49        pop %edi
50        pop %esi
51        pop %edx
52        pop %ecx
53
54        pop %ecx  /* pop esp */
55        pop %edx  /* pop eip */
56
57        sysexit
58