Does DiskonChip work on IDT RC32334 CPU(MIPS)?

David Woodhouse dwmw2 at
Mon Oct 22 07:06:51 EDT 2001

changyj at said:
>  My embedded linux system is MIPS(IDT RC32334 RISC CPU). The BIOS can
> detect DiskOnChip at 0xB2000000 address.

> How do I setup the physical address of DiskOnChip for  Memory
> Technology Device Subsystem in Linux ?  Is the address same as
> 0xB2000000?

It works on the Momenco Ocelot MIPS board - all the endianness funnies have 
been worked out. Check that 0xb2000000 is a _physical_ address, not a 
virtual address - it looks suspicious for a MIPS system, where normally 
only addresses under 0x20000000 are easily accessible. 

Also check how the DiskOnChip is wired up - whether its registers are 1 
byte, 2 bytes or 4 bytes apart as the CPU sees them. Look at the various 
forms of the ReadDOC_() and WriteDOC_() macros in include/linux/mtd/doc2000.h
and pick the correct one (or experiment).

Make sure the bus controller is set up properly for the wiring of the 
DiskOnChip too - for the Ocelot, we had to do that ourself, because the 
boot loader didn't (see the last two lines of momenco_ocelot_setup() in 


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