- biossums utility for the Bochs BIOS adapted for the LGPL'd VGABIOS

- VESA3 PMINFO checksum calculated in the source
- 24 bpp mode entries fixed (patch from Fabrice Bellard)

3 files changed, 216 insertions, 8 deletions

diff --git a/Makefile b/Makefile
index 7e6633f..9138c55 100644
--- a/Makefile
+++ b/Makefile
@@ -13,12 +13,12 @@ VGABIOS_DATE = "-DVGABIOS_DATE=\"$(RELDATE)\""
 all: bios cirrus-bios
 
 
-bios: vgabios.bin vgabios.debug.bin 
+bios: biossums vgabios.bin vgabios.debug.bin 
 
 cirrus-bios: vgabios-cirrus.bin vgabios-cirrus.debug.bin 
 
 clean:
-	/bin/rm -f  *.o *.s *.ld86 \
+	/bin/rm -f  biossums *.o *.s *.ld86 \
           temp.awk.* vgabios*.orig _vgabios_* _vgabios-debug_* core vgabios*.bin vgabios*.txt $(RELEASE).bin *.bak
 
 dist-clean: clean
@@ -38,6 +38,7 @@ vgabios.bin: vgabios.c vgabios.h vgafonts.h vgatables.h vbe.h vbe.c vbetables.h
 	as86 _vgabios_.s -b vgabios.bin -u -w- -g -0 -j -O -l vgabios.txt
 	rm -f _vgabios_.s _vgabios_.c vgabios.s
 	mv vgabios.bin VGABIOS-lgpl-latest.bin
+	./biossums VGABIOS-lgpl-latest.bin
 	ls -l VGABIOS-lgpl-latest.bin
 
 vgabios.debug.bin: vgabios.c vgabios.h vgafonts.h vgatables.h vbe.h vbe.c vbetables.h
@@ -47,6 +48,7 @@ vgabios.debug.bin: vgabios.c vgabios.h vgafonts.h vgatables.h vbe.h vbe.c vbetab
 	as86 _vgabios-debug_.s -b vgabios.debug.bin -u -w- -g -0 -j -O -l vgabios.debug.txt
 	rm -f _vgabios-debug_.s _vgabios-debug_.c vgabios-debug.s
 	mv vgabios.debug.bin VGABIOS-lgpl-latest.debug.bin
+	./biossums VGABIOS-lgpl-latest.debug.bin
 	ls -l VGABIOS-lgpl-latest.debug.bin
 
 vgabios-cirrus.bin: vgabios.c vgabios.h vgafonts.h vgatables.h clext.c
@@ -56,6 +58,7 @@ vgabios-cirrus.bin: vgabios.c vgabios.h vgafonts.h vgatables.h clext.c
 	as86 _vgabios-cirrus_.s -b vgabios-cirrus.bin -u -w- -g -0 -j -O -l vgabios.cirrus.txt
 	rm -f _vgabios-cirrus_.s _vgabios-cirrus_.c vgabios-cirrus.s
 	mv vgabios-cirrus.bin VGABIOS-lgpl-latest.cirrus.bin
+	./biossums VGABIOS-lgpl-latest.cirrus.bin
 	ls -l VGABIOS-lgpl-latest.cirrus.bin
 
 vgabios-cirrus.debug.bin: vgabios.c vgabios.h vgafonts.h vgatables.h clext.c
@@ -65,4 +68,8 @@ vgabios-cirrus.debug.bin: vgabios.c vgabios.h vgafonts.h vgatables.h clext.c
 	as86 _vgabios-cirrus-debug_.s -b vgabios.cirrus.debug.bin -u -w- -g -0 -j -O -l vgabios.cirrus.debug.txt
 	rm -f _vgabios-cirrus-debug_.s _vgabios-cirrus-debug_.c vgabios-cirrus-debug.s
 	mv vgabios.cirrus.debug.bin VGABIOS-lgpl-latest.cirrus.debug.bin
+	./biossums VGABIOS-lgpl-latest.cirrus.debug.bin
 	ls -l VGABIOS-lgpl-latest.cirrus.debug.bin
+
+biossums: biossums.c
+	gcc -o biossums biossums.c
diff --git a/biossums.c b/biossums.c
new file mode 100644
index 0000000..bb1d0ad
--- /dev/null
+++ b/biossums.c
@@ -0,0 +1,200 @@
+/* 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;
+}
diff --git a/clext.c b/clext.c
index d842add..e0ff9ac 100644
--- a/clext.c
+++ b/clext.c
@@ -244,10 +244,10 @@ cirrus_mode_t cirrus_modes[] =
    cseq_1024x768x16,cgraph_svgacolor,ccrtc_1024x768x16,16,
    6,5,10,5,5,5,0,1,15},
 
- {0xe0,800,600,24,0xe5,
+ {0x78,800,600,24,0xe5,
    cseq_800x600x24,cgraph_svgacolor,ccrtc_800x600x24,24,
    6,8,16,8,8,8,0,0,0},
- {0xe1,1024,768,24,0xe5,
+ {0x79,1024,768,24,0xe5,
    cseq_1024x768x24,cgraph_svgacolor,ccrtc_1024x768x24,24,
    6,8,16,8,8,8,0,0,0},
 
@@ -283,7 +283,7 @@ unsigned short cirrus_vesa_modelist[] = {
 // 800x600x16
   0x114, 0x65,
 // 800x600x24
-  0x115, 0xe0,
+  0x115, 0x78,
 // 1024x768x8
   0x105, 0x60,
 // 1024x768x15
@@ -291,7 +291,7 @@ unsigned short cirrus_vesa_modelist[] = {
 // 1024x768x16
   0x117, 0x74,
 // 1024x768x24
-//0x118, 0xe1,
+//0x118, 0x79,
 // invalid
   0xffff,0xffff
 };
@@ -1517,8 +1517,9 @@ cirrus_vesa_selB800_data:
 cirrus_vesa_selC000_data:
   dw 0xC000 ;; sel_C0000
 cirrus_vesa_is_protected_mode:
-  db 0x00 ;; is_protected_mode
-  db 0x00 ;; check_sum
+  ;; protected mode flag and checksum
+  dw (~((0xf2 + (cirrus_vesa_pmbios_entry >> 8) + (cirrus_vesa_pmbios_entry) \
+     + (cirrus_vesa_pmbios_init >> 8) + (cirrus_vesa_pmbios_init)) & 0xff) << 8) + 0x01
 ASM_END
 #endif // CIRRUS_VESA3_PMINFO