diff options
Diffstat (limited to 'contrib/syslinux/syslinux-4.03/core/callback.inc')
| -rw-r--r-- | contrib/syslinux/syslinux-4.03/core/callback.inc | 215 |
1 files changed, 0 insertions, 215 deletions
diff --git a/contrib/syslinux/syslinux-4.03/core/callback.inc b/contrib/syslinux/syslinux-4.03/core/callback.inc deleted file mode 100644 index d98d800..0000000 --- a/contrib/syslinux/syslinux-4.03/core/callback.inc +++ /dev/null @@ -1,215 +0,0 @@ -;; ----------------------------------------------------------------------- -;; -;; Copyright 1994-2009 H. Peter Anvin - All Rights Reserved -;; Copyright 2009 Intel Corporation; author: H. Peter Anvin -;; -;; This program is free software; you can redistribute it and/or modify -;; it under the terms of the GNU General Public License as published by -;; the Free Software Foundation, Inc., 53 Temple Place Ste 330, -;; Boston MA 02111-1307, USA; either version 2 of the License, or -;; (at your option) any later version; incorporated herein by reference. -;; -;; ----------------------------------------------------------------------- - -;; -;; callback.inc -;; -;; Callbacks from 32-bit mode to 16-bit mode -;; - -; -; 16-bit intcall/farcall handling code -; - -; -; 32-bit support code -; - bits 32 - section .text - -; -; Intcall/farcall invocation. We manifest a structure on the real-mode stack, -; containing the com32sys_t structure from <com32.h> as well as -; the following entries (from low to high address): -; - Target offset -; - Target segment -; - Return offset -; - Return segment (== real mode cs == 0) -; - Return flags -; - global core_farcall -core_farcall: - mov eax,[esp+1*4] ; CS:IP - jmp core_syscall - - global core_intcall -core_intcall: - movzx eax,byte [esp+1*4] ; INT number - mov eax,[eax*4] ; Get CS:IP from low memory - -core_syscall: - pushfd ; Save IF among other things... - push ebx - push ebp - push esi - push edi - push dword [CallbackSP] - - cld - - movzx edi,word [word RealModeSSSP] - movzx ebx,word [word RealModeSSSP+2] - sub edi,54 ; Allocate 54 bytes - mov [word RealModeSSSP],di - shl ebx,4 - add edi,ebx ; Create linear address - - mov esi,[esp+8*4] ; Source regs - xor ecx,ecx - mov cl,11 ; 44 bytes to copy - rep movsd - - ; EAX is already set up to be CS:IP - stosd ; Save in stack frame - mov eax,.rm_return ; Return seg:offs - stosd ; Save in stack frame - mov eax,[edi-12] ; Return flags - and eax,0x200ed7 ; Mask (potentially) unsafe flags - mov [edi-12],eax ; Primary flags entry - stosw ; Return flags - - mov bx,.rm - jmp enter_rm ; Go to real mode - - bits 16 - section .text16 -.rm: - mov ax,sp - add ax,9*4+4*2 - mov [CallbackSP],ax - pop gs - pop fs - pop es - pop ds - popad - popfd - retf ; Invoke routine - -.rm_return: - ; We clean up SP here because we don't know if the - ; routine returned with RET, RETF or IRET - mov sp,[cs:CallbackSP] - pushfd - pushad - push ds - push es - push fs - push gs - mov ebx,.pm_return - jmp enter_pm - - ; On return, the 44-byte return structure is on the - ; real-mode stack, plus the 10 additional bytes used - ; by the target address (see above.) - bits 32 - section .text -.pm_return: - movzx esi,word [word RealModeSSSP] - movzx eax,word [word RealModeSSSP+2] - mov edi,[esp+9*4] ; Dest regs - shl eax,4 - add esi,eax ; Create linear address - and edi,edi ; NULL pointer? - jnz .do_copy -.no_copy: mov edi,esi ; Do a dummy copy-to-self -.do_copy: xor ecx,ecx - mov cl,11 ; 44 bytes - rep movsd ; Copy register block - - add dword [word RealModeSSSP],54 - ; Remove from stack - - pop dword [CallbackSP] - pop edi - pop esi - pop ebp - pop ebx - popfd - ret ; Return to 32-bit program - -; -; Cfarcall invocation. We copy the stack frame to the real-mode stack, -; followed by the return CS:IP and the CS:IP of the target function. -; The value of IF is copied from the calling routine. -; - global core_cfarcall -core_cfarcall: - pushfd ; Save IF among other things... - push ebx - push ebp - push esi - push edi - push dword [CallbackSP] - - cld - mov ecx,[esp+9*4] ; Size of stack frame - - movzx edi,word [word RealModeSSSP] - movzx ebx,word [word RealModeSSSP+2] - mov [word CallbackSP],di - sub edi,ecx ; Allocate space for stack frame - and edi,~3 ; Round - sub edi,4*3 ; Return pointer, return value, EFLAGS - mov [word RealModeSSSP],di - shl ebx,4 - add edi,ebx ; Create linear address - - mov eax,[esp+5*4] ; EFLAGS from entry - and eax,0x202 ; IF only - stosd - mov eax,[esp+7*4] ; CS:IP - stosd ; Save to stack frame - mov eax,.rm_return ; Return seg:off - stosd - mov esi,[esp+8*4] ; Stack frame - mov eax,ecx ; Copy the stack frame - shr ecx,2 - rep movsd - mov ecx,eax - and ecx,3 - rep movsb - - mov bx,.rm - jmp enter_rm - - bits 16 - section .text16 -.rm: - popfd - retf -.rm_return: - mov sp,[cs:CallbackSP] - mov esi,eax - mov ebx,.pm_return - jmp enter_pm - - bits 32 - section .text -.pm_return: - mov eax,esi - ; EDX already set up to be the RM return value - pop dword [CallbackSP] - pop ebx - pop ebp - pop esi - pop edi - popfd - ret - - bits 16 - section .bss16 - alignb 4 -CallbackSP resd 1 ; SP saved during callback - - bits 16 - section .text16 |