BCOS 80x86 Common PC BIOS Module File Format Specification

BCOS 80x86 Common PC BIOS Module File Format Specification
Version 1.0
(Preliminary Draft)

Contents

1                Overview
2                General File Structure
3                File Format
3.1                Generic File Header
3.2                Extended Header
3.3                Executable Code and Data

1   Overview

The Common PC BIOS Module is a simple executable file that is used to complete the firmware specific part of boot on behalf of boot loaders designed for the PC BIOS (so that code doesn't need to be duplicated in each of these boot loaders).

2   General File Structure

The basic structure of the file is described in Figure 2.1: File Layout.

Figure 2.1 - File Layout

3   File Format

3.1   Generic File Header

This is the native file format header defined in BCOS Native File Format Specification.

3.2   Extended Header

The extended header follows the generic file header, and is described in Table 3.1: Extended Header Format.

Offset

Size

Description

0x00000020

2 bytes

Offset within code segment for entry point

Table 3.1 - Extended Header Format

Note: Refer to Common PC BIOS Module Transition State Specification, Section 5.1: Common PC BIOS Module Entry Point for complete details of the Common PC BIOS Module's entry point.

3.3 Executable Code and Data

The boot loader is responsible for complying with the Common PC BIOS Module Transition State Specification before starting Common PC BIOS Module. The Common PC BIOS Module is responsible for complying with the BCOS Transition State 1 Specification before starting the (firmware independant) Boot Manager.

Generated on Tue Sep 22 05:34:46 2009