1 | // Copyright 2019 The Marl Authors. |
2 | // |
3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
4 | // you may not use this file except in compliance with the License. |
5 | // You may obtain a copy of the License at |
6 | // |
7 | // https://www.apache.org/licenses/LICENSE-2.0 |
8 | // |
9 | // Unless required by applicable law or agreed to in writing, software |
10 | // distributed under the License is distributed on an "AS IS" BASIS, |
11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
12 | // See the License for the specific language governing permissions and |
13 | // limitations under the License. |
14 | |
15 | #if defined(__i386__) |
16 | |
17 | #define MARL_BUILD_ASM 1 |
18 | #include "osfiber_asm_x86.h" |
19 | |
20 | // void marl_fiber_swap(marl_fiber_context* from, const marl_fiber_context* to) |
21 | // esp+4: from |
22 | // esp+8: to |
23 | .text |
24 | .global marl_fiber_swap |
25 | .align 4 |
26 | marl_fiber_swap: |
27 | // Save context 'from' |
28 | movl 4(%esp), %eax |
29 | |
30 | // Store callee-preserved registers |
31 | movl %ebx, MARL_REG_EBX(%eax) |
32 | movl %ebp, MARL_REG_EBP(%eax) |
33 | movl %esi, MARL_REG_ESI(%eax) |
34 | movl %edi, MARL_REG_EDI(%eax) |
35 | |
36 | movl (%esp), %ecx /* call stores the return address on the stack before jumping */ |
37 | movl %ecx, MARL_REG_EIP(%eax) |
38 | lea 4(%esp), %ecx /* skip the pushed return address */ |
39 | movl %ecx, MARL_REG_ESP(%eax) |
40 | |
41 | // Load context 'to' |
42 | movl 8(%esp), %ecx |
43 | |
44 | // Load callee-preserved registers |
45 | movl MARL_REG_EBX(%ecx), %ebx |
46 | movl MARL_REG_EBP(%ecx), %ebp |
47 | movl MARL_REG_ESI(%ecx), %esi |
48 | movl MARL_REG_EDI(%ecx), %edi |
49 | |
50 | // Load stack pointer |
51 | movl MARL_REG_ESP(%ecx), %esp |
52 | |
53 | // Load instruction pointer, and jump |
54 | movl MARL_REG_EIP(%ecx), %ecx |
55 | jmp *%ecx |
56 | |
57 | #endif // defined(__i386__) |
58 | |