When do I need to specify add_efi_memmap as kernel argument in UEFI/EFI boot?

Question

Sencha Touch Architect is giving me this error when I set-up a store, a rest proxy and then try and load data into the store.

TypeError: 'null' is not an object (evaluating 'reader.getReaderType')

Has anyone had this issue or knows a work-around?

Solution 1

Boot loaders, or Grub for that matter, rebuilds the memory map like e820, I guess this is the reason why you are seeing different values between GRUB and the EFI stub loader.

There is a comment in the Linux source code which says that EFI allows "more than the max 128 entries that can fit in the e820 legacy (zeropage) memory map.". This seems not to be the case according to the numbers you posted, hence I doubt that adding add_efi_memmap is helpful... However, it certainly doesn't hurt to parse this table too...

Solution 2

If your Linux distribution successfully EFI STUB boots, there is no need to use add_efi_memmap. This kernel command line option is rarely needed nowadays - UEFI firmware and Linux kernel support for same has significantly improved since 2009 era.