[U-Boot] [PATCH v2 07/11] sandbox: Map host memory for efi_loader

Heinrich Schuchardt xypron.glpk at gmx.de
Thu Jun 14 19:21:49 UTC 2018


On 06/14/2018 09:02 PM, Simon Glass wrote:
> Hi Alex,
> 
> On 14 June 2018 at 12:22, Alexander Graf <agraf at suse.de> wrote:
>> With efi_loader we do not control payload applications, so we can not
>> teach them about the difference between virtual and physical addresses.
>>
>> Instead, let's just always map host virtual addresses in the efi memory
>> map. That way we can be sure that all memory allocation functions always
>> return consumable pointers.
>>
>> Signed-off-by: Alexander Graf <agraf at suse.de>
>>
>> ---
>>
>> v1 -> v2:
>>
>>   - only compile efi_add_known_memory if efi_loader is enabled
>> ---
>>  arch/sandbox/cpu/cpu.c | 20 ++++++++++++++++++++
>>  1 file changed, 20 insertions(+)
> 
> NAK.
> 
> You should not point sandbox pointers into the EFI tables. I know it
> looks like a clever shortcut, but it is not correct. It will mess up
> logging and debugging, since those pointers bear no easily accessible
> relationship to U-Boot address.

Hello Simon,

why do we need this Babylonic confusion of addresses which do not point
to valid memory and pointers that are not valid addresses where
everybody is getting lost?

Simply use only addresses with there mmap'ed values and get rid of all
conversions. Use your board file to adjust kernel_addr_r and the like to
the address range that Linux offered you.

Best regards

Heinrich

> 
> Please start from my v7 patch. I'm happy to help do this correctly.
> But, again, I think it should come after we have basic sandbox EFI
> support applied.
> 
> Regards,
> Simon
> 



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