11 Sep
2003
11 Sep
'03
11:05 p.m.
When Linux boots, it assumes the BIOS is brain-dead and reconfigures everything. The BCSR and IMMR will be relocated to what makes sense for that operating environment.
This is not enirely true for PPC Linux. It is true for x86. On PPC, Linux assumes that the BIOS or bootloader initalizes all the board or CPU specific hardware. Like the FCCs for ehternet, serial ports (for initial debug output), IO pins used by FCCs, and serial ports.(linux doesn't touch thesse)
Some of the meory map (specifically where the IMMR and to a lesser extent BCSR) Linux depends on the bootloader to tell it where they are.