On Fri, Jul 09, 2004 at 06:50:00PM +0000, S C wrote: > Using MontaVista Linux 3.1 on a Toshiba RBTx4938 board. Using YAMON, when I > download the kernel via the debug ethernet port it runs fine. If I download > the kernel via the Tx4938 inbuilt ethernet controller, it crashes! If you're using a Montavista kernel you should report to Montavista. We don't have the source so any comment here is speculation. > The crash is occuring inside the function r4k_flush_icache_range(). > > I tried 'flush -i' and 'flush -d' on YAMON after the download but before > the 'go', but that didn't help. I also tried completely disabling caches > and loading/running uncached, but it gave the same error. > > Now, the final twist! Using an ICE, I set a breakpoint at the > r4k_flush_icache_range function. Then I loaded the kernel as usual, ran it > with the ICE, stepped through a few instructions inside the > r4k_flush_icache_range function and then did a 'cont'. The kernel now > booted fine! As already pointed out by the other poster Niels Sterrenburg using a debugger unavoidably changes the state of the system to be debugged. For at least some of the TX49xx processors there is a problem under certain circumstances if a flush of an I-cache line flushes that cache instruction itself. Make sure you're not getting hit by that one. Ralf
