The memory map is initialized via ArmConfigureMmu, which builds the initial translation tables. This code is in ArmPkg\Library\ArmMmuLib\Arm\ArmMmuLibCore.c, and it does "FillTranslationTable()". This occurs in PEI/SEC before MMU is first enabled. This code does not just use sections -- it uses PopulateLevel2PageTable to create page tables for regions that are not modulo 1MB in size.
The start of my memory map has: Base 0x00000000 Size 0x00018000 Attr ARM_MEMORY_REGION_ATTRIBUTE_DEVICE Which is the only region that matters really. I know the ArmMmuLib was recently changed/moved. Perhaps this is a side effect of that change? Can the mover of that code comment? It seems strange that Arm's code would set itself up one way but then assume another setup. K2 -----Original Message----- From: Ard Biesheuvel [mailto:ard.biesheu...@linaro.org] Sent: Wednesday, September 21, 2016 10:21 AM To: Kurt Kennett <kurt.kenn...@microsoft.com> Cc: edk2-devel <edk2-devel@lists.01.org> Subject: Re: [edk2] Problem with Arm Mmu code in CpuDxe On 21 September 2016 at 17:09, Kurt Kennett <kurt.kenn...@microsoft.com> wrote: > I am having a problem on my system (assert), and during investigation I may > have found a problem with the Arm CpuDxe Mmu code that may affect all ARM > platform users. > > CpuDxeInitialize is the entry point, and pretty soon after entry it does: > > SyncCacheConfig (&mCpu); > > This calls into: > ArmPkg\Drivers\CpuDxe\Arm\Mmu.c > > The code asserts that the Mmu is enabled, gets the memory space map, then > starts to process the page tables by getting the TTBR0 base address. Before the assert, there is a comment that says // This code assumes MMU is enabled and filed [sic] with section translations I don't know if this is a reasonable thing to assume, and how you end up violating this assumption, but it does explain why the code does not work correctly. What does your memory map look like? _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
