On 12.09.17 10:18, Heinrich Schuchardt wrote:
On 09/12/2017 05:00 AM, Bin Meng wrote:
Hi Heinrich,
On Sun, Sep 10, 2017 at 4:55 PM, Heinrich Schuchardt xypron.glpk@gmx.de wrote:
Variable EFI_LDS is set based on CONFIG_EFI_STUB_64BIT. It influences which lds script is used for compiling helloworld.efi. This results in building helloworld.efi failing on x86_64 if CONFIG_EFI_STUB_64BIT is not set. CONFIG_EFI_STUB_64BIT is only visible if EFI_STUB is selected. We should be able to compile a 64bit helloworld.efi irrespective of EFI_STUB.
With the patch the bitness of the efi build is taken from the architecture choice.
Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de
For proper testing https://lists.denx.de/pipermail/u-boot/2017-September/305184.html must be fixed.
So I send this as RFC.
Sorry I missed this. This does not go to the U-Boot ML. Did you intend to keep the discussion among us?
CC: U-Boot Mailing List u-boot@lists.denx.de
Alex, do you remember why CONFIG_EFI_STUB_64BIT was introduced in the first place.
The CONFIG_EFI_STUB_64BIT was introduced to support booting from a 64-bit EFI BIOS.
Would you ever use a stub with a different bitness than U-Boot?
Yes, for example U-Boot x86 32-bit to boot a 64-bit EFI payload.
My understanding is that the EFI stub is used if U-Boot is loaded as an EFI application.
It has nothing to do with the EFI application or driver loaded by U-boot's bootefi command, which I assume you reference as "to boot a 64-bit EFI payload".
A stub with different bitness than U-Boot would be needed if we wanted to load 64 bit U-Boot as a 32 bit EFI application or a 32 bit U-Boot as a 64 bit EFI application. Is this required in any scenario?
That's what Bin just explained, no? Running U-Boot on x86 as 32bit binary was/is quite common, but usually you're running on a 64bit UEFI implementation.
Or you want to run 64-bit U-Boot on an older Mac which only has 32bit UEFI...
Alex