Firmware Test Suite - apicinstance test

This test checks that the Standard BIOS 32-bit Service Directory header is sanely configured.

Example output from this test:

Check BIOS32 Service Directory.
Test 1 of 1: Check BIOS32 Service Directory.
This test tries to find and sanity check the BIOS32 Service Directory as defined
in the Standard BIOS 32-bit Service Directory Proposal, Revision 0.4 May 24,
1993, Phoenix Technologies Ltd and also the PCI BIOS specification.
Found BIOS32 Service Directory at 0x000f2550
  Signature  : _32_
  Entry Point: 0x000fc200
  Revsion    : 0x00
  Length     : 0x01
  Checksum   : 0x0b

PASSED: Test 1, Service Directory Entry Point 0x000fc200 is not in high memory.
PASSED: Test 1, Service Directory Length is 1 (1 x 16 bytes) as expected.
PASSED: Test 1, Service Directory Revision is 0x00 and is supported by the
PASSED: Test 1, Service Directory checksum passed.


sudo fwts bios32 -

..runs the test on your machine and dumps the output to stdout.

Explanation of test results

Certain test results may require a little more explanation. This section will try and give some context to specific test failures.

Error ID



Service Directory Entry Point is in high memory and hence cannot be used by the kernel.


Service Directory structure is the wrong size, it should be 16 bytes long.


Service Directory revision is not recognised and may not be supported by the kernel.


Service Directory checksum error.


Multiple Service Directories were found, there should be just one.

FirmwareTestSuite/Reference/bios32 (last edited 2016-01-11 07:25:12 by anthonywong)