"Get EDID" Boot Floppy

"Get EDID" Boot Floppy
File: util/getedid/0index.asm

Copyright © Brendan Trotter 2008

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Overview

This index file determines the layout of all other source files in memory. The final binary is a 1440 KiB floppy image that can be used to obtain the EDID information from the monitor, create a file (in the native file format - see BCOS EDID File Format Specification) and store this file on the floppy starting from the third sector. This allows the EDID information to be copied from the floppy disk into a normal file (and then included in a Boot Image).

WARNING: This code is a quick hack!

21: %include "asm.inc"

Assembler Setup

27:       ORG 0x7C00
28:
29:       BITS 16
30:       CPU 386
31:
32:       section .bss
33: BSS_START:
34:       section .text

Start of Binary and Entry Point

41: ;Input
42: ; dl BIOS device number
43:
44: jmp 0x000:START

BIOS Parameter Block

50:                   times ($$-$+0x00B) nop
51:
52:                   dw 0x0200               ;0x00B, Bytes per sector
53:                   db 1                    ;0x00D, Sectors per cluster
54:                   dw 80*18*2              ;0x00E, Sectors in reserved area
55:                   db 0                    ;0x010, Number of copies of FAT
56:                   db 0                    ;0x011, Number of root directory entries (low byte)
57: STACK_TOP:
58:                   db 0                    ;0x011, Number of root directory entries (high byte)
59:                   dw 80*18*2              ;0x013, Total number of sectors
60:                   db 0                    ;0x015, Media descriptor
61:                   dw 0                    ;0x016, Number of sectors per FAT
62: sectorsPerTrack:  dw 18                   ;0x018, Number of sectors per track
63: totalHeads:       dw 2                    ;0x01A, Number of heads
64:                   dd 80*18*2              ;0x01C, Number of hidden sectors
65:                   dd 80*18*2              ;0x020, Total number of sectors

Source Code - Part 1

72: %include "init.asm"
73: %include "abort.asm"
74: %include "video/init.asm"
75: %include "video/print.asm"
76: %include "data1.asm"

Bootable Marker

82: times ($$-$+0x01FE) db 0x00
83: dw 0xAA55

Source Code - Part 2

89: %include "data2.asm"
90: %include "getedid.asm"
91: %include "header.asm"
92: %include "write.asm"

The End

Here we define a few labels that are used later.

101:       align 512
102:       section .bss
103:       alignb 16
104: BSS_END:

Generated on Sat Aug 1 16:05:47 2009