diff options
Diffstat (limited to 'swtch.S')
| -rw-r--r-- | swtch.S | 36 |
1 files changed, 15 insertions, 21 deletions
@@ -1,32 +1,26 @@ -# void swtch(struct context *old, struct context *new); +# void swtch(struct context **old, struct context **new); # # Save current register context in old # and then load register context from new. .globl swtch swtch: - # Save old registers movl 4(%esp), %eax + movl 8(%esp), %edx - popl 0(%eax) # %eip - movl %esp, 4(%eax) - movl %ebx, 8(%eax) - movl %ecx, 12(%eax) - movl %edx, 16(%eax) - movl %esi, 20(%eax) - movl %edi, 24(%eax) - movl %ebp, 28(%eax) + # Save old callee-save registers + pushl %ebp + pushl %ebx + pushl %esi + pushl %edi - # Load new registers - movl 4(%esp), %eax # not 8(%esp) - popped return address above - - movl 28(%eax), %ebp - movl 24(%eax), %edi - movl 20(%eax), %esi - movl 16(%eax), %edx - movl 12(%eax), %ecx - movl 8(%eax), %ebx - movl 4(%eax), %esp - pushl 0(%eax) # %eip + # Switch stacks + movl %esp, (%eax) + movl (%edx), %esp + # Load new callee-save registers + popl %edi + popl %esi + popl %ebx + popl %ebp ret |