Hi Alex, Heinrich,
At present not all interfaces in lib/efi_loader/efi_runtime.c are declared as __efi_runtime. But only declaring those as __efi_runtime is not enough. The data these interfaces use should be declared as __efi_runtime_data too. More worse, any U-Boot APIs called by these interfaces should be __efi_runtime and __efi_runtime_data respectively.
Eventually we need mark the RAM where the whole U-Boot image lives as runtime service code and data and end up leaving whole U-Boot image in the RAM after kernel boots?
Right now I am testing booting Linux on Intel Galileo with 'bootefi' and kernel just hangs during the boot. Initial debugging shows that kernel crashes when calling runtime service efi_set_virtual_address_map().
Regards, Bin