git.joshuawise.com / netwatch.git / blame
| Commit | Line | Data |
|---|---|---|
| 3c4e084d JP |
1 | # pagingstub-asm.s |
| 2 | # Paging-enable helper routines | |
| 3 | # NetWatch system management mode administration console | |
| 4 | # | |
| 5 | # Copyright (c) 2008 Jacob Potter and Joshua Wise. All rights reserved. | |
| 6 | # This program is free software; you can redistribute and/or modify it under | |
| 7 | # the terms found in the file LICENSE in the root of this source tree. | |
| 9e2a82e4 JP |
8 | |
| 9 | .globl set_cr0 | |
| 10 | ||
| 11 | set_cr0: | |
| 12 | mov 4(%esp), %eax # Load argument | |
| 13 | movl %eax, %cr0 # Set CR0 | |
| 14 | pushw %cs # Push 16 bits of %CS | |
| 15 | pushl $set_cr0_cont # Push 32 bits of %EIP | |
| 16 | ljmp *(%esp) # "Far jump" (both %CS and %EIP from stack) | |
| 17 | set_cr0_cont: # Hey, here we are! | |
| 18 | addl $6, %esp # Un-do 48 bits of pushing | |
| 19 | ret | |
| 20 | ||
| 8e404e68 JP |
21 | |
| 22 | .globl ps_switch_stack | |
| 23 | ps_switch_stack: | |
| 24 | mov 4(%esp), %eax | |
| 25 | mov 8(%esp), %esp | |
| 4e3ef36b JW |
26 | # Put a sentinel value (FEEDFACE) at the top of the stack |
| 27 | mov $0xCEFAEDFE, %edx | |
| 28 | push %edx | |
| 29 | push %edx | |
| 30 | push %edx | |
| 31 | push %edx | |
| 8e404e68 JP |
32 | call *%eax |
| 33 | rsm |