On 19 September 2018 at 15:55, Vladimir Olovyannikov <
[email protected]> wrote:
> Hi All,
>
>
>
> I need UEFI experts help on the problem with Armv8 board on warm UEFI
> reset.
>
> Cold reset works fine.
>
>
>
> Here is how I set up a warm reset:
>
>
>
> STATIC
>
> EFI_STATUS
>
> ShutdownUefiBootServices (
>
> VOID
>
> )
>
> {
>
> EFI_STATUS Status;
>
> UINTN MemoryMapSize;
>
> EFI_MEMORY_DESCRIPTOR *MemoryMap;
>
> UINTN MapKey;
>
> UINTN DescriptorSize;
>
> UINT32 DescriptorVersion;
>
> UINTN Pages;
>
>
>
> MemoryMap = NULL;
>
> MemoryMapSize = 0;
>
> Pages = 0;
>
>
>
> do {
>
> Status = gBS->GetMemoryMap (
>
> &MemoryMapSize,
>
> MemoryMap,
>
> &MapKey,
>
> &DescriptorSize,
>
> &DescriptorVersion
>
> );
>
> if (Status == EFI_BUFFER_TOO_SMALL) {
>
>
>
> Pages = EFI_SIZE_TO_PAGES (MemoryMapSize) + 1;
>
> MemoryMap = AllocatePages (Pages);
>
>
>
> //
>
> // Get System MemoryMap
>
> //
>
> Status = gBS->GetMemoryMap (
>
> &MemoryMapSize,
>
> MemoryMap,
>
> &MapKey,
>
> &DescriptorSize,
>
> &DescriptorVersion
>
> );
>
> }
>
>
>
> // Don't do anything between the GetMemoryMap() and ExitBootServices()
>
> if (!EFI_ERROR(Status)) {
>
> Status = gBS->ExitBootServices (gImageHandle, MapKey);
>
> if (EFI_ERROR(Status)) {
>
> FreePages (MemoryMap, Pages);
>
> MemoryMap = NULL;
>
> MemoryMapSize = 0;
>
> }
>
> }
>
> } while (EFI_ERROR(Status));
>
>
>
> return Status;
>
> }
>
>
>
> Then perform
>
> ArmCleanDataCache ();
>
> ArmInvalidateDataCache ();
>
> ArmDisableInstructionCache ();
>
> ArmInvalidateInstructionCache ();
>
These don't do anything useful on ARM. You can only reliably perform cache
maintenance by virtual address.
ArmDisableMmu ();
>
>
>
... so after this call returns, all bets are off with regards to whether
what is popped from the stack is actually what we pushed when we entered
the function.
> Then jump to start of FV:
>
>
>
> typedef
>
> VOID
>
> (EFIAPI *START_FV)(
>
> VOID
>
> );
>
> StartOfFv = (START_FV)(UINTN)PcdGet64(PcdFvBaseAddress);
>
> StartOfFv ();
>
>
>
> Now this is what happens on warm reset:
>
> reset -c warm
>
> 1. Until ArmEnableMmu() gets called, everything works as expected.
>
> Here is the stack right before ArmEnableMmu() is called:
>
> ArmConfigureMmu+0x4f8
>
> InitMmu+0x24
>
> MemoryPeim+0x440
>
> PrePiMain+0x114
>
> PrimaryMain+0x68
>
> CEntryPoint+0xC4
>
> EL2:0x00000000800008BC
>
> ----- End of stack info -----
>
>
>
> 2. Here is the stack as soon as Mmu is enabled with ArmEnableMmu() :
>
> ArmConfigureMmu+0x4fc <-- This one is correct, at line 745 in
> ArmConfigureMmu() in ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
> (return EFI_SUCCESS)
>
> _ModuleEntryPoint+0x24 <-- Wrong. This points directly to
> ASSERT(FALSE); and to CpuDeadLoop() in DxeCoreEntryPoint.c, lines 59-60.
>
> El2:0x000000008E5E8300 <-- Absolutely bogus
>
> --- End of stack info ---
>
>
>
> So, as soon as ArmEnableMmu() exits, execution jumps directly to
> CpuDeadLoop() in DxeCoreEntryPoint of _ModuleEntryPoint().
>
>
>
> Would be grateful for any advice.
>
>
>
> Thank you,
>
> Vladimir
>
>
>
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