From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <38FBA3AA.3864AAA0@execpc.com> Date: Mon, 17 Apr 2000 18:52:10 -0500 From: Joseph Garcia MIME-Version: 1.0 To: Tim Wojtulewicz CC: "linuxppc-dev@lists.linuxppc.org" Subject: Re: setpramboot problems References: <38E6B0BF.1A3FECC5@execpc.com> <38FB9AF7.4E541642@dana.ucc.nau.edu> Content-Type: text/plain; charset=iso-2022-jp Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Tim Wojtulewicz wrote: > I'm having a small problem wit h SetPRAMBoot. This is most likely an error on my > part (doh!). I used it to set the boot PRAM so I could boot back to macos. The > values I used were 2 0 0 9. I'm thinking this is /dev/hda9. Is this incorrect? > Anyways, I tried to use the zap-PRAM keys to reset the thing, but it doesn't > recognize that I'm holding them down, and just boots directly back to linux. > Tried to boot from a cd, computer ignores that I'm holding C down. System is a > Pismo Powerbook, Linux PPC 2000, with Ben's 2.2.15-pre14 kernel. Any ideas? yaBoot is probably what you use on a pismo, which is an OF booter. setpramboot might not effect that. I think 'C' might be another of the MacOS ROM things, like the PRAM boot value. Using OF directly can bypass the ROM, but im not sure exactly how yaBoot works. Though a few issues have popped up with setpramboot. This weekend, I got my hands on some other systems. I found that the linux kernel maps NVRAM differently on NewWorld systems (OF >= 3.0), which includes the 101/lombard. As a result, the 4 bytes setpramboot modifies are in a different location. What the kernel does also seems to break nvsetenv. using hexdump on /dev/nvram, the PRAM boot location is on line 0x1370 with oldworld, and 0x1220 with newworld if i recall correctly. Any kernel maintainers know why this happens? (running Paul's 2.2.15pre17, dmesg lists where various nvram sections are mapped, so the kernel knows that the address is different) Regarding setpramboot, its definitely still a work in progress. I still have yet to figure out the meaning of the code when the bus is scsi. the ata setting makes sense, but the SCSI setting is still cryptic. fyi, even if scsi, 'System Disk' still only changes those 4 bytes, so a simple cut and paste of known correct values would work. Maybe I should put a hexcode option in the /etc/pramtab. I might have a chance update setpramboot this weekend. Thanks. -- Joseph P. Garcia jpgarcia@execpc.com jpgarcia@lidar.ssec.wisc.edu CS Undergraduate Student Employee - Systems Programmer University of Wisconsin - Madison UW Lidar Group "Did you ever notice how the Chinese Abacus, with 2 '5' beads and 5 '1' beads, is perfect for hexidecimal math?" ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/