[U-Boot] [PATCH v2] efi_loader: Check machine type in the image header

[Heinrich Schuchardt]

On 04/06/2018 01:23 AM, Alexander Graf wrote:
> 
> 
> On 06.04.18 01:03, Heinrich Schuchardt wrote:
>> On 04/06/2018 12:43 AM, Alexander Graf wrote:
>>>
>>>
>>> On 05.04.18 23:28, Ivan Gorinov wrote:
>>>> Check FileHeader.Machine to make sure the EFI executable image is built
>>>> for the same architecture. For example, 32-bit U-Boot on x86 will print
>>>> an error message instead of loading an x86_64 image and crashing.
>>>>
>>>> Signed-off-by: Ivan Gorinov <ivan.gorinov at intel.com>
>>>> ---
>>>>  include/pe.h                      | 24 ++++++++++++++++++++++++
>>>>  lib/efi_loader/efi_image_loader.c | 24 ++++++++++++------------
>>>>  2 files changed, 36 insertions(+), 12 deletions(-)
>>>>
>>>> diff --git a/include/pe.h b/include/pe.h
>>>> index c3a19ce..0dc33f0 100644
>>>> --- a/include/pe.h
>>>> +++ b/include/pe.h
>>>> @@ -38,11 +38,35 @@ typedef struct _IMAGE_DOS_HEADER {
>>>>  #define IMAGE_DOS_SIGNATURE		0x5A4D     /* MZ   */
>>>>  #define IMAGE_NT_SIGNATURE		0x00004550 /* PE00 */
>>>>  
>>>> +#define IMAGE_FILE_MACHINE_I386		0x014c
>>>>  #define IMAGE_FILE_MACHINE_ARM		0x01c0
>>>>  #define IMAGE_FILE_MACHINE_THUMB	0x01c2
>>>>  #define IMAGE_FILE_MACHINE_ARMNT	0x01c4
>>>>  #define IMAGE_FILE_MACHINE_AMD64	0x8664
>>>>  #define IMAGE_FILE_MACHINE_ARM64	0xaa64
>>>> +#define IMAGE_FILE_MACHINE_RISCV32	0x5032
>>>> +#define IMAGE_FILE_MACHINE_RISCV64	0x5064
>>>> +
>>>> +#if defined(CONFIG_ARM64)
>>>> +#define TARGET_PE_MACHINE_TYPE IMAGE_FILE_MACHINE_ARM64
>>>> +#elif defined(CONFIG_ARM)
>>>> +#define TARGET_PE_MACHINE_TYPE IMAGE_FILE_MACHINE_THUMB
>>>
>>> Are you sure we always have thumb as machine type here? Aren't we
>>> compatible with either ARM or THUMB?
>>
>> The value 0x01c2 means ARM or THUMB
>> It is used by Linux, GRUB, iPXE.
> 
> I'm not sure that's fully accurate. ARM means some old legacy one, but
> ARMNT and THUMB can both be used, no?
> 
>   https://www.npmjs.com/package/binarycpu
> 
> What I'm trying to say is that a 1:1 matching might not be the only
> thing we want.

Revision 8.3 – February 6th, 2013 of the PECOFF spec is the most explicit:

IMAGE_FILE_MACHINE_ARMNT 0x1c4 ARMv7 (or higher) Thumb mode only
IMAGE_FILE_MACHINE_THUMB 0x1c2 ARM or Thumb (“interworking”)

EDK2 has only these values (with some names not matching the standard):

IMAGE_FILE_MACHINE_I386            0x014c
IMAGE_FILE_MACHINE_IA64            0x0200
IMAGE_FILE_MACHINE_EBC             0x0EBC
IMAGE_FILE_MACHINE_X64             0x8664
IMAGE_FILE_MACHINE_ARMTHUMB_MIXED  0x01c2
IMAGE_FILE_MACHINE_ARM64           0xAA64

On ARM only IMAGE_FILE_MACHINE_ARMTHUMB_MIXED and
IMAGE_FILE_MACHINE_ARMTHUMB_MIXED are IMAGE_FILE_MACHINE_EBC are
supported. But we do not support IMAGE_FILE_MACHINE_EBC.

So EDK2 would not be able load a 0x01c4 ARM binary.

Best regards

Heinrich