Hello Jean-Michel and Greg, Please add "coldfire' in the title and the explanation of this patch. Best regards Philippe On Wed, Sep 04, 2024 at 04:26:14PM +0200, Jean-Michel Hautbois wrote:
Some of the internal SoC registers have a higher priority over the MMU virtual mappings. The SRAM bank is one of them. If the bootloader enables the internal SRAM at address 0x80000000, virtual memory access at this address will not hit the MMU - so no TLB data misses would occurr. Since 0x80000000 is the virtual start address of all applications that bit of memory is getting stomped over with inconsistent code and data access. Fix it by disabling the internal SRAM at startup. Signed-off-by: Greg Ungerer <gerg@xxxxxxxxxxxxxx> Tested-by: Jean-Michel Hautbois <jeanmichel.hautbois@xxxxxxxxxx> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@xxxxxxxxxx> --- arch/m68k/coldfire/head.S | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/m68k/coldfire/head.S b/arch/m68k/coldfire/head.S index c6d7fd28c6023..3901a49c47c89 100644 --- a/arch/m68k/coldfire/head.S +++ b/arch/m68k/coldfire/head.S @@ -207,6 +207,10 @@ _start: movec %d0,%CACR nop + movel #0,%d0 + movec %d0,%rambar + nop + #ifdef CONFIG_MMU /* * Identity mapping for the kernel region. --- base-commit: 431c1646e1f86b949fa3685efc50b660a364c2b6 change-id: 20240904-fix-cf-virt-mem-sram-abadb27fff2f Best regards, -- Jean-Michel Hautbois <jeanmichel.hautbois@xxxxxxxxxx>
