[U-Boot-Users] Memory Caching in Interrupt mode

[Sharad Gupta <sharad@buckeye.ece.drexel.edu>]

Hi All,

I am using UBoot as a firmware and boot loader for a custom development 
board based on MPC7455.

I understand UBoot is not intended for use in interrupt modes, but I 
thought it does no harm in outputting some text on serial console 
everytime an interrupt comes in, say a timer interrupt (every 1 sec). I 
am using BDI2000 to start debugging at 0x900. But my problem is that 
since address translation is turned off while processing interrupts, I 
am not able to write to the serial port address since processor caches 
it and does not really push it out to the serial port. I am using 
ns16550 driver and the serial port is at 0x60000000.

Whats the work around for this problem ?

1. Shall I turn the address translation on, but I am not sure if its 
safe to do that, and even if I do that where exactly should I do that, 
in timer_interrupt routine or transfer_to_handler routine ?
2. Or shall i disable the data caches while processing interrupts ?


Thanks
Sharad.