Windows 9x QuickInstall Update Blog

[oerg866]

This is a test!

[oerg866]

Time to use this blog thing!

Update on Intel 865/875 Hang Issue

So, I've been looking into this Intel 865/875 USB issue (more precisely, anything with ICH5) in more detail...

The reported symptom is: Installation hangs during Hardware Detection or Installation hangs on boot or USB controller driver doesn't load properly.

After many attempts with the kernel debugger and correspondence with @LordOfMice, I've decided: I'm officially too stupid to fix it :\

The problem lies in the BIOS interrupt handler for the internal SATA device. To my understanding, it doesn't seem to be designed to share interrupts with other devices, and in Enhanced SATA mode, one of the UHCI controllers and the EHCI controller share the same IRQ. This problem doesn't occur in "Primary/Secondary IDE" mode, as it always uses IRQ 14, as is typical for an IDE controller.

The problem can be circumvented by disabling the USB controller or by running the SATA controller in Primary/Secondary IDE mode (or compatibility mode or however your BIOS may call it).

This isn't an issue under NT-based systems or Linux of course, since they are all entirely 32-bit, but Windows 9x keeps the storage driver in real mode until just before the desktop loads, so the IRQ handler in the BIOS is still relevant.

You may ask: How did nobody notice this back then? But consider this: Windows 9x was never bootable in Enhanced SATA Mode (potentially 6 IDE devices), because the ESDI_506.PDR was never designed for that. Back then, you would always install in compatibility mode on these boards if you even had a SATA drive in 2003/2004. So... problem broken, as you can see...

Instead, I've added a new module called "hwquirks" to the installer, which runs a sequence of checks after the installation is configured. If one of them triggers, the user is informed and has the option to cancel.