/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
*
* 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; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
.arch i386
.section ".text16", "awx", @progbits
.section ".text16.data", "aw", @progbits
.section ".data16", "aw", @progbits
/****************************************************************************
* !PXE structure
****************************************************************************
*/
.section ".text16.data"
.globl ppxe
.align 16
ppxe:
.ascii "!PXE" /* Signature */
.byte pxe_length /* StructLength */
.byte 0 /* StructCksum */
.byte 0 /* StructRev */
.byte 0 /* reserved_1 */
.word undiheader, 0 /* UNDIROMID */
.word 0, 0 /* BaseROMID */
.word pxe_entry_sp, 0 /* EntryPointSP */
.word pxe_entry_esp, 0 /* EntryPointESP */
.word -1, -1 /* StatusCallout */
.byte 0 /* reserved_2 */
.byte SegDescCnt /* SegDescCnt */
.word 0 /* FirstSelector */
pxe_segments:
.word 0, 0, 0, _data16_size /* Stack */
.word 0, 0, 0, _data16_size /* UNDIData */
.word 0, 0, 0, _text16_size /* UNDICode */
.word 0, 0, 0, _text16_size /* UNDICodeWrite */
.word 0, 0, 0, 0 /* BC_Data */
.word 0, 0, 0, 0 /* BC_Code */
.word 0, 0, 0, 0 /* BC_CodeWrite */
.equ SegDescCnt, ( ( . - pxe_segments ) / 8 )
.equ pxe_length, . - ppxe
.size ppxe, . - ppxe
/* Define undiheader=0 as a weak symbol for non-ROM builds */
.section ".weak"
.weak undiheader
undiheader:
/****************************************************************************
* PXENV+ structure
****************************************************************************
*/
.section ".text16.data"
.globl pxenv
.align 16
pxenv:
.ascii "PXENV+" /* Signature */
.word 0x0201 /* Version */
.byte pxenv_length /* Length */
.byte 0 /* Checksum */
.word pxenv_entry, 0 /* RMEntry */
.long 0 /* PMEntry */
.word 0 /* PMSelector */
.word 0 /* StackSeg */
.word _data16_size /* StackSize */
.word 0 /* BC_CodeSeg */
.word 0 /* BC_CodeSize */
.word 0 /* BC_DataSeg */
.word 0 /* BC_DataSize */
.word 0 /* UNDIDataSeg */
.word _data16_size /* UNDIDataSize */
.word 0 /* UNDICodeSeg */
.word _text16_size /* UNDICodeSize */
.word ppxe, 0 /* PXEPtr */
.equ pxenv_length, . - pxenv
.size pxenv, . - pxenv
/****************************************************************************
* pxenv_entry (16-bit far call)
*
* PXE API call PXENV+ entry point
*
* Parameters:
* %es:di : Far pointer to PXE parameter structure
* %bx : PXE API call
* Returns:
* %ax : PXE exit status
* Corrupts:
* none
****************************************************************************
*/
.section ".text16"
.code16
pxenv_entry:
pushl $pxe_api_call
pushw %cs
call prot_call
addl $4, %esp
lret
.size pxenv_entry, . - pxenv_entry
/****************************************************************************
* pxe_entry
*
* PXE API call !PXE entry point
*
* Parameters:
* stack : Far pointer to PXE parameter structure
* stack : PXE API call
* Returns:
* %ax : PXE exit status
* Corrupts:
* none
****************************************************************************
*/
.section ".text16"
.code16
pxe_entry:
pxe_entry_sp:
/* Preserve original %esp */
pushl %esp
/* Zero high word of %esp to allow use of common code */
movzwl %sp, %esp
jmp pxe_entry_common
pxe_entry_esp:
/* Preserve %esp to match behaviour of pxe_entry_sp */
pushl %esp
pxe_entry_common:
/* Save PXENV+ API call registers */
pushw %es
pushw %di
pushw %bx
/* Load !PXE parameters from stack into PXENV+ registers */
addr32 movw 18(%esp), %bx
movw %bx, %es
addr32 movw 16(%esp), %di
addr32 movw 14(%esp), %bx
/* Make call as for PXENV+ */
pushw %cs
call pxenv_entry
/* Restore PXENV+ registers */
popw %bx
popw %di
popw %es
/* Restore original %esp and return */
popl %esp
lret
.size pxe_entry, . - pxe_entry
/****************************************************************************
* pxe_int_1a
*
* PXE INT 1A handler
*
* Parameters:
* %ax : 0x5650
* Returns:
* %ax : 0x564e
* %es:bx : Far pointer to the PXENV+ structure
* CF cleared
* Corrupts:
* none
****************************************************************************
*/
.section ".text16"
.code16
.globl pxe_int_1a
pxe_int_1a:
pushfw
cmpw $0x5650, %ax
jne 1f
/* INT 1A,5650 - PXE installation check */
pushw %cs
popw %es
movw $pxenv, %bx
movw $0x564e, %ax
popfw
clc
lret $2
1: /* INT 1A,other - pass through */
popfw
ljmp *%cs:pxe_int_1a_vector
.section ".text16.data"
.globl pxe_int_1a_vector
pxe_int_1a_vector: .long 0
