thanks olivier and Leif.

ganapat

On Wed, Apr 2, 2014 at 11:08 PM, Olivier Martin olivier.martin@arm.comwrote:

Hi Ganapat,

The issue is actually in GetEnvironmentVariable(). The function should have copied the default value to reflect the behaviour of value loaded from RUNTIME_SERVICES.GetVariable().

I fixed the issue in SVN rev 15427 (2nd April 2014).

Thanks a lot for having reported the issue,

Olivier

*From:* linaro-uefi-bounces@lists.linaro.org [mailto: linaro-uefi-bounces@lists.linaro.org] *On Behalf Of *Ganapatrao Kulkarni *Sent:* 01 April 2014 06:57 *To:* linaro-uefi@lists.linaro.org *Subject:* Re: [Linaro-uefi] ARM64: seeing FDT DevicePath node Corruption!!

any comments?

On Mon, Mar 24, 2014 at 5:10 PM, Ganapatrao Kulkarni gpkulkarni@gmail.com wrote:

In my case, both variables DefaultFdtDevicePath and FdtDevicePath are holding the same address. this is because the function gRT->GetVariable (as called from GetEnvironmentVariable) returing status as 14(EFI_NOT_FOUND) and hence code setting FdtDevicePath same as DefaultFdtDevicePath (This is rootcause for the issue what i explained in previous email).

IMHO, it is a potential bug to execute FreePool (DefaultFdtDevicePath) unconditionally.

the probable fix could be,

diff --git a/ArmPlatformPkg/Bds/BootOption.c b/ArmPlatformPkg/Bds/BootOption.c index edd193e..be93d28 100644 --- a/ArmPlatformPkg/Bds/BootOption.c +++ b/ArmPlatformPkg/Bds/BootOption.c @@ -90,6 +90,7 @@ BootOptionStart ( Status = GetEnvironmentVariable ((CHAR16 *)L"Fdt", &gArmGlobalVariableGuid, DefaultFdtDevicePath, &FdtDevicePathSize, (VOID **)&FdtDevicePath); ASSERT_EFI_ERROR(Status);

•  if (DefaultFdtDevicePath != FdtDevicePath)
     FreePool (DefaultFdtDevicePath);
   }
   Status = BdsBootLinuxFdt (BootOption->FilePathList,
  
  
  

please comment?

regards Ganapat

On Sun, Mar 23, 2014 at 11:50 PM, Ganapatrao Kulkarni gpkulkarni@gmail.com wrote:

...

Hi,

I am trying to port edk2 to our ARM64 platform simulator and seeing strange behaviour.

I see the content of FdtDevicePath is getting changed, after executing the function BdsLoadImage() to load the Linux Image file. Because of this, when BdsLoadImage function is called to load the fdt.dtb file, the execution goes in infinite loop.

After debugging, i am seeing that, it is happenig due to corrution of FDT device path.

Before the BdsLoadImage() called to load Linux Image file, the FDT device path(0xFBC8B918) content is valid, ie DevicePathFdt->Type = 1. DevicePathFdt ->SubType= 4. DevicePathFdt->Lenght[0] = 20.

After the Linux Image is loaded, it is changes as below, DevicePathFdt->Type = 112 DevicePathFdt ->SubType= 111 DevicePathFdt->Lenght[0] = 100

further debugging, i see this happening by below lines of code, in

function

...

CoreLocateHandle(), MdeModulePkg/Core/Dxe/Hand/Locate.c

// // Increase the resulting buffer size, and if this handle // fits return it // ResultSize += sizeof(Handle); if (ResultSize <= *BufferSize) { *ResultBuffer = Handle; <= this line is corrupting the devicepath of FDT. ResultBuffer += 1; } }

Not able to understand what causing this corruption. Any clue on what is going wrong? Any suggestions for further debugging?

BTW, I am using edk2 source from git://git.linaro.org/uefi/linaro-edk2.git, branch master

thanks Ganapat