Power-Up 2-7
The SROM contents are loaded into each CPU’s I-cache and executed on power-
up/reset. After testing the caches on each processor chip, it tests the path to the
XSROM. Once this path is tested and deemed reliable, layers of the XSROM are
loaded sequentially into the processor chip on each CPU. None of the SROM or
XSROM power-up tests are run from memory—all run from the caches in the CPU
chip, thus providing excellent diagnostic isolation. Later power-up tests, run under
the console, are used to complete testing of the I/O subsystem.
There are two console programs: the SRM console and the AlphaBIOS console, as
detailed in the AlphaServer 1200 System User’s Guide (EK–1200?–UG). By default,
the SRM console is always loaded and I/O system tests are run under it before the
system loads AlphaBIOS. To load AlphaBIOS, the os_type environment variable
must be set to NT and “halt assertion” must be clear. Otherwise, the SRM console
continues to run.
