Joerg Schilling wrote: >Cyril Plisko <cyril.plisko at gmail.com> wrote: > > > > >>It sounds like it is possible. However, I do not understand these things >>enough >>to have a clear opinion. On SPARC, when I hit Stop-A I get back to "ok" prompt >>and have an OBP working. However, not all of the facilities are available >>at that point (AFAIR) until I reset-all it. >> >>
Not only when Stop+A'ing a running system (bootet Solaris kernel), but the same behaviour also appears after a full, proper shutdown with # init 0 or # halt (for example) So it is more than just a catched exception. A sparc system has to be "reset-all" (or "reset" on certain older OBP's) in order to be fully functioning again, after a kernel had been loaded before. > >I believe that the OF on Sparc knows which commands would be dangerous to the >booted program (Solaris) and forbid them. > > Yes and no, rather no. Yes: It does give a warning on certain commands, i.e. "probe-scsi" or "probe-scsi-all". I get the following (OpenBoot 4.16.4 / SB2000): ok probe-scsi This command may hang the system if a Stop-A or halt command has been executed. Please type reset-all or reset te system before executing this command. Do you wish to continue? (y/n) So you have at least choice on thos catched commands. However, some dangerous commands are not catched at all. Just do a "probe-all" on a Blade 2000 and everything seems to be dead. I then realized, that just vga was hanging, keyboard still worked. (was a booted, running Sol10_03/05 system) There were worse problems with some versions of Sol9_sparc where you would even get to any ok prompt, but where the system would be forced to dump and reboot when you hit Stop+A or halted / init 0 'ed the machine / bug was USB-framework related). Then I halted another Blade 2000 with "init 0". The same here (same as on a still running/fully booted box, interestingly) : Got a warning on "probe-scsi-all". Got no warning on "probe-all". This time not VGA was black, but I permanently got USB / kbd timeout errors. Then the kernel paniced (Why is that beast still running at all, after a "halt"???) and reboot was forced. Even different situation on VOF on prep, though: #0) No Stop+A or friend found, did it exist on PowerPC ?? Probably not. #1) No way to get back from a booted system to any ok promt. Not even after doing a "init 0" or halt. martin >J?rg > > >
