+++ /dev/null
-/* biossums.c --- written by Eike W. for the Bochs BIOS */
-/* adapted for the LGPL'd VGABIOS by vruppert */
-
-#include <stdlib.h>
-#include <stdio.h>
-
-typedef unsigned char byte;
-
-void check( int value, char* message );
-
-#define LEN_BIOS_DATA 0x8000
-#define MAX_OFFSET (LEN_BIOS_DATA - 1)
-
-
-#define BIOS_OFFSET 0x7FFF
-
-long chksum_bios_get_offset( byte* data, long offset );
-byte chksum_bios_calc_value( byte* data, long offset );
-byte chksum_bios_get_value( byte* data, long offset );
-void chksum_bios_set_value( byte* data, long offset, byte value );
-
-
-#define PMID_LEN 20
-#define PMID_CHKSUM 19
-
-long chksum_pmid_get_offset( byte* data, long offset );
-byte chksum_pmid_calc_value( byte* data, long offset );
-byte chksum_pmid_get_value( byte* data, long offset );
-void chksum_pmid_set_value( byte* data, long offset, byte value );
-
-
-byte bios_data[LEN_BIOS_DATA];
-
-
-int main( int argc, char* argv[] ) {
-
- FILE* stream;
- long offset, tmp_offset;
- byte cur_val = 0, new_val = 0;
- int hits;
-
-
- if( argc != 2 ) {
- printf( "Error. Need a file-name as an argument.\n" );
- exit( EXIT_FAILURE );
- }
-
- if(( stream = fopen( argv[1], "rb" )) == NULL ) {
- printf( "Error opening %s for reading.\n", argv[1] );
- exit( EXIT_FAILURE );
- }
- if( fread( bios_data, 1, LEN_BIOS_DATA, stream ) >= LEN_BIOS_DATA ) {
- printf( "Error reading max. 32767 Bytes from %s.\n", argv[1] );
- fclose( stream );
- exit( EXIT_FAILURE );
- }
- fclose( stream );
-
- hits = 0;
- offset = 0L;
- while( (tmp_offset = chksum_pmid_get_offset( bios_data, offset )) != -1L ) {
- offset = tmp_offset;
- cur_val = chksum_pmid_get_value( bios_data, offset );
- new_val = chksum_pmid_calc_value( bios_data, offset );
- printf( "\nPMID entry at: 0x%4lX\n", offset );
- printf( "Current checksum: 0x%02X\n", cur_val );
- printf( "Calculated checksum: 0x%02X ", new_val );
- hits++;
- }
- if( hits == 1 && cur_val != new_val ) {
- printf( "Setting checksum." );
- chksum_pmid_set_value( bios_data, offset, new_val );
- }
- if( hits >= 2 ) {
- printf( "Multiple PMID entries! No checksum set." );
- }
- if( hits ) {
- printf( "\n" );
- }
-
-
- offset = 0L;
- offset = chksum_bios_get_offset( bios_data, offset );
- cur_val = chksum_bios_get_value( bios_data, offset );
- new_val = chksum_bios_calc_value( bios_data, offset );
- printf( "\nBios checksum at: 0x%4lX\n", offset );
- printf( "Current checksum: 0x%02X\n", cur_val );
- printf( "Calculated checksum: 0x%02X ", new_val );
- if( cur_val != new_val ) {
- printf( "Setting checksum." );
- chksum_bios_set_value( bios_data, offset, new_val );
- }
- printf( "\n" );
-
-
- if(( stream = fopen( argv[1], "wb" )) == NULL ) {
- printf( "Error opening %s for writing.\n", argv[1] );
- exit( EXIT_FAILURE );
- }
- if( fwrite( bios_data, 1, LEN_BIOS_DATA, stream ) < LEN_BIOS_DATA ) {
- printf( "Error writing 32KBytes to %s.\n", argv[1] );
- fclose( stream );
- exit( EXIT_FAILURE );
- }
- fclose( stream );
-
- return( EXIT_SUCCESS );
-}
-
-
-void check( int okay, char* message ) {
-
- if( !okay ) {
- printf( "\n\nError. %s.\n", message );
- exit( EXIT_FAILURE );
- }
-}
-
-
-long chksum_bios_get_offset( byte* data, long offset ) {
-
- return( BIOS_OFFSET );
-}
-
-
-byte chksum_bios_calc_value( byte* data, long offset ) {
-
- int i;
- byte sum;
-
- sum = 0;
- for( i = 0; i < MAX_OFFSET; i++ ) {
- sum = sum + *( data + i );
- }
- sum = -sum; /* iso ensures -s + s == 0 on unsigned types */
- return( sum );
-}
-
-
-byte chksum_bios_get_value( byte* data, long offset ) {
-
- return( *( data + BIOS_OFFSET ) );
-}
-
-
-void chksum_bios_set_value( byte* data, long offset, byte value ) {
-
- *( data + BIOS_OFFSET ) = value;
-}
-
-
-byte chksum_pmid_calc_value( byte* data, long offset ) {
-
- int i;
- int len;
- byte sum;
-
- len = PMID_LEN;
- check( offset + len <= MAX_OFFSET, "PMID entry length out of bounds" );
- sum = 0;
- for( i = 0; i < len; i++ ) {
- if( i != PMID_CHKSUM ) {
- sum = sum + *( data + offset + i );
- }
- }
- sum = -sum;
- return( sum );
-}
-
-
-long chksum_pmid_get_offset( byte* data, long offset ) {
-
- long result = -1L;
-
- while( offset + PMID_LEN < MAX_OFFSET ) {
- offset = offset + 1;
- if( *( data + offset + 0 ) == 'P' && \
- *( data + offset + 1 ) == 'M' && \
- *( data + offset + 2 ) == 'I' && \
- *( data + offset + 3 ) == 'D' ) {
- result = offset;
- break;
- }
- }
- return( result );
-}
-
-
-byte chksum_pmid_get_value( byte* data, long offset ) {
-
- check( offset + PMID_CHKSUM <= MAX_OFFSET, "PMID checksum out of bounds" );
- return( *( data + offset + PMID_CHKSUM ) );
-}
-
-
-void chksum_pmid_set_value( byte* data, long offset, byte value ) {
-
- check( offset + PMID_CHKSUM <= MAX_OFFSET, "PMID checksum out of bounds" );
- *( data + offset + PMID_CHKSUM ) = value;
-}