On 05/10/2013 07:06:47 AM, Tom Rini wrote:
On Sun, Apr 28, 2013 at 04:53:08PM -0000, Kuo-Jung Su wrote:
From: Kuo-Jung Su dantesu@faraday-tech.com
With MMU/D-Cache enabled, data might be retained at d-cache rather than at DRAM when we execute 'go' command, and some of the bare-metal softwares would always invalidate the entire data cache at start-up, and then leads to a data lost issue. Furthermore, the U-Boot not only relocates itself but also updates symbol table at start-up, which means the i-cache might also be dirty, so it would be better to invalidates the i-cache alone with d-cache flush.
This patch is designed to fix the issues above. It has been verified at ARM based systems, and should also work at other platforms.
This patch has a few not trivially solvable problems. First, the only weak version of invalidate_icache_all is in common/cmd_cache.c. The only defined version of the function is for ARMv7 CPUs. So, everyone that is not ARMv7 and does not have CONFIG_CMD_CACHE will not build now.
And I'm not seeing a globally defined CONFIG to say "Yes, we are ARMv7" or "Yes, we have icache to invalidate".
This actually seems related to the cache flush issue that Freescale folks brought up a few weeks ago. Or maybe that's my pre-coffee brain talking.
Yes, it's the same issue that we were talking about. mpc85xx does have flush_dcache() and invalidate_icache() which could be used for this, though they're currently missing the "_all" suffix.
-Scott