# # Copyright (c) 2001-2004 Jakub Jermar # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions # are met: # # - Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # - Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in the # documentation and/or other materials provided with the distribution. # - The name of the author may not be used to endorse or promote products # derived from this software without specific prior written permission. # # THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR # IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES # OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. # IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT # NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF # THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. # #include #include #include .text ## Save current CPU context # # Save CPU context to the context_t variable # pointed by the 1st argument. Returns 1 in EAX. # FUNCTION_BEGIN(context_save_arch) movl 0(%esp), %eax # save pc value into eax movl 4(%esp), %edx # address of the context variable to save context to # save registers to given structure movl %esp, CONTEXT_OFFSET_SP(%edx) # %esp -> ctx->sp movl %eax, CONTEXT_OFFSET_PC(%edx) # %eip -> ctx->pc movl %ebx, CONTEXT_OFFSET_EBX(%edx) # %ebx -> ctx->ebx movl %esi, CONTEXT_OFFSET_ESI(%edx) # %esi -> ctx->esi movl %edi, CONTEXT_OFFSET_EDI(%edx) # %edi -> ctx->edi movl %ebp, CONTEXT_OFFSET_EBP(%edx) # %ebp -> ctx->ebp mov vreg_ptr, %ecx movl %gs:VREG_TP(%ecx), %ecx movl %ecx, CONTEXT_OFFSET_TP(%edx) xorl %eax, %eax # context_save returns 1 incl %eax ret FUNCTION_END(context_save_arch) ## Restore saved CPU context # # Restore CPU context from context_t variable # pointed by the 1st argument. Returns 0 in EAX. # FUNCTION_BEGIN(context_restore_arch) movl 4(%esp), %eax # address of the context variable to restore context from # restore registers from given structure movl CONTEXT_OFFSET_SP(%eax), %esp # ctx->sp -> %esp movl CONTEXT_OFFSET_PC(%eax), %edx # ctx->pc -> \pc movl CONTEXT_OFFSET_EBX(%eax), %ebx # ctx->ebx -> %ebx movl CONTEXT_OFFSET_ESI(%eax), %esi # ctx->esi -> %esi movl CONTEXT_OFFSET_EDI(%eax), %edi # ctx->edi -> %edi movl CONTEXT_OFFSET_EBP(%eax), %ebp # ctx->ebp -> %ebp movl %edx, 0(%esp) # put saved pc on stack mov vreg_ptr, %ecx movl CONTEXT_OFFSET_TP(%eax), %edx movl %edx, %gs:VREG_TP(%ecx) xorl %eax, %eax # context_restore returns 0 ret