Comment # 6 on bug 954126 from Andrei Borzenkov

OK, I found bootmgfw.efi, and it confirms it. The problem is in
grub2-efi-chainload-harder.patch that adds check for valid PE32+ header; but
this check is wrong.

  if (grub_memcmp (pe32->signature, "PE\0\0", 4) != 0

pe32 header is not located at fixed address. pe32 is of type grub_pe32_header
and expects header at offset 0x80; but botomgfw.efi has header at offset 0xe0.
See PE COFF specification. Code should fetch header address at fixed offset
0x3b.

Cc patch author.