Sunday, March 21, 2010

back to OpenBIOS

Since SS-5 OBP works pretty well, I think it's a good time to get back to OpenBIOS: it's free (as in speech), and can support more than 256 MiBs RAM.  Theoretically Ross's SPARCStation-20 OBP supports up to 2 GiB RAM, but frankly speaking I think having a more or less hardware-precise SS-5 is enough.

The very first experience has shown that bootblk loads ufsboot successfully, but then it hangs. I'm feeling myself getting back few months in the past. Back then I was debugging pretty much similar routines in the bootblk, but the main job was done by Mitch Bradley. I sort of hoped I skipped the necessity to learn the gory details of the UFS filesystem. Ok, back to school. ;-) . My very first long shot:

$ strings sun4m/ufsboot
 ['] find-device catch if 2drop true else current-device device-end then swap l!

Trying to find out whether this sentence works I found out that OpenBIOS doesn't support input lines longer than 80 characters! It would be interesting to find out whether it's just a console limitation, or the API too. If it's an API limitation it may be exactly the bug that prevents Solaris from booting.

Another observing:

0 > " /openprom" ['] find-device  ok
3 > . . . -29a594 9 -264cec  ok

  • "ok" is not a prompt, but a response. I don't think it's important.
  • It operates with signed hexadecimals. This looks pretty weird. Here comes the same question again: is this just a console representation, or another API bug.

Gonna check it with OpenBIOS developers.

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