analog_programmer wrote on 2023-12-31, 15:40:
I'll gladly test your newer patched BIOS version for Shuttle HOT-596A board when it's ready.
Hi analog_programmer,
The new HOT-569A patch J.3 BIOS version is ready and I sent you a download link via PM.
Please let us know how this new BIOS works.
P.S. Some stupid question: If your HDD volume compatibility BIOS patches are almost the same as the ones applied by the BIOS Patcher software, why BIOS Patcher applies its HDD-patches over already manually patched by you BIOSes? I've never used such HDD-volume double patched BIOSes, just tried what more will be autopatched (mostly for adding support for more CPUs) and noticed this strange BIOS Patcher behavior.
My BIOS patching method involves making a good disassembly listing of the BIOS, then analyze what needs to be changed. Then I edit the BIOS firmware directly in machine code with a hexeditor, followed by another run through the disassembler to check the result, and to see if I got it right. This method is indeed quite time consuming but works on both compressed and uncompressed BIOSes and allows me to catch unique bugs.
The BIOS patcher tool from apple_rom works by adding compressed modules with the patches to the compressed BIOS image. The patches are then applied in Shadow RAM during each boot-up. A quite clever approach for compressed BIOSes and this usually works well. But there have been several cases where it bricked a system, but luckily the developer(s) have put in a fall-back feature that allows you to boot with the original BIOS. Just hold down the “–“ (minus) key on the numeric keypad during boot and the patches are not applied.
Now when you run the BIOS Patcher tool on one of my patched BIOSes, the program may not recognize the bug because I changed the original code.
Then the tool will either not apply that particular patch, or tries to patch my patch. The later can result in unpredictable behaviour.
Regards, Jan