diff options
Diffstat (limited to 'roms/ipxe/src/arch/i386/interface/pxe/pxe_entry.S')
| -rw-r--r-- | roms/ipxe/src/arch/i386/interface/pxe/pxe_entry.S | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/roms/ipxe/src/arch/i386/interface/pxe/pxe_entry.S b/roms/ipxe/src/arch/i386/interface/pxe/pxe_entry.S new file mode 100644 index 00000000..6274264f --- /dev/null +++ b/roms/ipxe/src/arch/i386/interface/pxe/pxe_entry.S @@ -0,0 +1,217 @@ +/* + * 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., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + * + */ + +FILE_LICENCE ( GPL2_OR_LATER ) + + .arch i386 + +/**************************************************************************** + * !PXE structure + **************************************************************************** + */ + .section ".text16.data", "aw", @progbits + .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_memsz /* Stack */ + .word 0, 0, 0, _data16_memsz /* UNDIData */ + .word 0, 0, 0, _text16_memsz /* UNDICode */ + .word 0, 0, 0, _text16_memsz /* 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", "a", @nobits + .weak undiheader +undiheader: + +/**************************************************************************** + * PXENV+ structure + **************************************************************************** + */ + .section ".text16.data", "aw", @progbits + .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_memsz /* StackSize */ + .word 0 /* BC_CodeSeg */ + .word 0 /* BC_CodeSize */ + .word 0 /* BC_DataSeg */ + .word 0 /* BC_DataSize */ + .word 0 /* UNDIDataSeg */ + .word _data16_memsz /* UNDIDataSize */ + .word 0 /* UNDICodeSeg */ + .word _text16_memsz /* 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 + **************************************************************************** + */ + /* Wyse Streaming Manager server (WLDRM13.BIN) assumes that + * the PXENV+ entry point is at UNDI_CS:0000; apparently, + * somebody at Wyse has difficulty distinguishing between the + * words "may" and "must"... + */ + .section ".text16.null", "ax", @progbits + .code16 +pxenv_null_entry: + jmp pxenv_entry + + .section ".text16", "ax", @progbits + .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", "ax", @progbits + .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 + * %edx : Physical address of the PXENV+ structure + * CF cleared + * Corrupts: + * none + **************************************************************************** + */ + .section ".text16", "ax", @progbits + .code16 + .globl pxe_int_1a +pxe_int_1a: + pushfw + cmpw $0x5650, %ax + jne 1f + /* INT 1A,5650 - PXE installation check */ + xorl %edx, %edx + movw %cs, %dx + movw %dx, %es + movw $pxenv, %bx + shll $4, %edx + addl $pxenv, %edx + movw $0x564e, %ax + pushw %bp + movw %sp, %bp + andb $~0x01, 8(%bp) /* Clear CF on return */ + popw %bp + popfw + iret +1: /* INT 1A,other - pass through */ + popfw + ljmp *%cs:pxe_int_1a_vector + + .section ".text16.data", "aw", @progbits + .globl pxe_int_1a_vector +pxe_int_1a_vector: .long 0 |