I'm thinking about trying coreboot on the Compaq Evo T20 thin client. This is a Geode GX1 machine with CS5530 companion chip and National Semiconductor DP83815 ethernet card. It has 48MB of flash memory and 64 MB of RAM (soldered). The superiotool from coreboot can't find any evidence of super-I/O. The mainboard contains a chip that looks like a socketed PLCC BIOS chip, Winbond 29C020... with a sticker on top giving credit to Wyse Tech 01'V9.0. The keyboard and mouse use a USB 1.1 interface. `lspci` says 00:13.0 USB Controller: Compaq ... ZFMicro Chipset USB (rev 06)
Expert advice on these questions would be very welcome:
1. Does coreboot support this setup? (Particularly the USB devices?)
2. What advantages will coreboot offer over the manufacturer's original BIOS? E.g., will I get a BIOS control screen I can use to change settings until they work?
3. I don't have too much time to indulge in hardware hacking. I'm hoping for an approach that would not require me to even open the Evo's case! And this might be possible: like the Wyse Winterm, the Evo boots from on-board flash memory that can be rewritten using 'netxfer'. One of the files that netxfer delivers to the thin client is called "the BIOS" by people who know these things. Tradition among users like me is to treat that file with great respect, making sure an exact copy of the factory original is present whenever other files in the bundle are replaced. Here's my main question: can I replace that file (named ulc_code.ce, size 4 MB) with something from coreboot and use 'netxfer' to get a working alternative to the factory BIOS? What can I test before trying this to make sure I don't turn my little device into a brick? Are there some magic bytes or signatures to look for in the factory-file to confirm that it really is some kind of BIOS, and that program execution starts from the same location in the commercial file as it will in coreboot? What else should I be watching for?
Thanks in advance for any comments or pointers.
Philip