----- Original Message ----- From: "Haavard Skinnemoen" <[EMAIL PROTECTED]> To: "Martin Jarman" <[EMAIL PROTECTED]> Cc: <u-boot@lists.denx.de> Sent: Friday, October 10, 2008 12:43 PM Subject: Re: [U-Boot] Special memory test Question
> Haavard Skinnemoen <[EMAIL PROTECTED]> wrote: >> to start at physical address zero and scribble over the entire physical >> address range of the processor until it eventually tries to access an >> invalid physical address and gets a bus error exception. > > Actually, that's wrong. It won't scribble over anything since it only > does reads. But it will access an invalid address and get a bus error > exception eventually. > >> Nope, it's a user error. Try running this command instead: >> >> loop.b 10400000 4 >> >> It's been running on my board for several minutes without crashing. > > Btw, that command won't actually test the SDRAM since do_mem_loop() > accesses cacheable memory. The first access will load the data into the > dcache, and subsequent accesses will simply read it from the dcache and > not cause any memory accesses. > > What is this command supposed to test anyway? It's highly unlikely that > it will find any SDRAM problems by simply reading an address without > checking the result... > > Haavard Thank you for your replies, and I accept my 'user error' (head hung in shame) and can confirm the test appears to run correctly when called with the proper arguments. I note Wolfgang has answered your question about what the test is for. best regards Martin Jarman _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
