[coreboot] [Bug?] 3 different bytes in VGAbios after upgrade to coreboot

Vladimir quickcracktime at gmail.com
Sun Jun 7 02:12:06 CEST 2015


Thank you very much for solving this riddle!
And one more question for Rudolf: please tell, are you using atomDis
utility to disassemble atombios into C code? Or there are some other
special tools, which probably have more recent versions? (latest version of
atomDis is already 4 years old...)

On 3 June 2015 at 20:27, Rudolf Marek <r.marek at assembler.cz> wrote:

> Hi all,
>
> First byte after IBM is usually a checksum. So in fact only two bytes
> differ.
> Now you may ask what it is... and it is a IOBASE :)
>
> typedef struct _ATOM_ROM_HEADER
> {
>   ATOM_COMMON_TABLE_HEADER sHeader;
>   UCHAR> uaFirmWareSignature[4];    /*Signature to distinguish between
> Atombios
> and non-atombios,atombios should init it as "ATOM", don't change the
> position */
>   USHORT usBiosRuntimeSegmentAddress;
>   USHORT usProtectedModeInfoOffset;
>   USHORT usConfigFilenameOffset;
>   USHORT usCRC_BlockOffset;
>   USHORT usBIOS_BootupMessageOffset;
>   USHORT usInt10Offset;
>   USHORT usPciBusDevInitCode;
>   USHORT usIoBaseAddress; <---------------this changes
>
> I guess IOBASE of PCI device changes also...
>
>   USHORT usSubsystemVendorID;
>   USHORT usSubsystemID;
>   USHORT usPCI_InfoOffset;.
>   USHORT usMasterCommandTableOffset; /*Offset for SW to get all command
> table
> offsets, Don't change the position */
>   USHORT usMasterDataTableOffset;   /*Offset for SW to get all data table
> offsets, Don't change the position */
>   UCHAR  ucExtendedFunctionCode;
>   UCHAR  ucReserved;
> }ATOM_ROM_HEADER;
>
> You can use atomDis to dump it I guess (Did not check if it dumps also the
> header.
>
> Thanks
> Rudolf
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.coreboot.org/pipermail/coreboot/attachments/20150607/214e321c/attachment.html>


More information about the coreboot mailing list