I downloaded U-boot from CVS on Nov 14th and have compiled and run this on a TQM8540 board (with a Rev 2 MPC8540 chip).
However, I started stepping through this with the CodeWarrior debugger (and a FreeScale USB TAP - COP version) find that the "isync" in the following code from start.S is actually causing Interrupt 14 to be executed (TLBInstructionException).
/* * Invalidate MMU L1/L2 * * Note: There is a fixup earlier for Errata CPU4 on * Rev 1 parts that must precede this MMU invalidation. */ li r2, 0x001e mtspr MMUCSR0, r2 isync <------------------- Interrupt
Without CodeWarrior, I do eventually see the U-Boot command line appear on the serial port (however it did take several seconds after power on, more than I expected).
Checking the 8540RM manual, I see that there appear to be only two bits that need to be set to invalidate cache (page 633 on MMUCSR0).
Can anyone on the explain the presence of
0x001e
as opposed to
0x0006
in the above code?
Any suggestions as to why this exception arises. Has anyone seen it with An Abatron BDI2000 or not - as the case may be.
Thanks,
Charles.
-------------------------------------------------------------------------- Dr Charles J Gillan The Institute of Electronics, Communications and Information Technology (ECIT), Queen's University Belfast, Titanic Quarter Queens Road, Queens Island, Belfast, BT3 9DT Northern Ireland, UK Tel: +44 (0) 2890 971847 Fax: +44 (0) 2890 971702 --------------------------------------------------------------------------