On 07/09/2014 08:44 AM, Michael Brown wrote: > > It is possible to create a .bss section in the PE/COFF header: iPXE does > this. For example: > > objdump -x bin-x86_64-efi/ipxe.efi > > Sections: > Idx Name Size VMA LMA File off Algn > 0 .text 00081948 0000000000001000 0000000000001000 000002c0 2**4 > CONTENTS, ALLOC, LOAD, READONLY, CODE > 1 .rodata 0002bf5e 0000000000082960 0000000000082960 00081c20 2**2 > CONTENTS, ALLOC, LOAD, DATA > 2 .data 0001fdf0 00000000000ae8c0 00000000000ae8c0 000adb80 2**4 > CONTENTS, ALLOC, LOAD, DATA > 3 .bss 000a27ac 00000000000ce700 00000000000ce700 00000000 2**4 > ALLOC > 4 .reloc 00001388 0000000000170ec0 0000000000170ec0 000cd980 2**2 > CONTENTS, ALLOC, LOAD, READONLY, DATA > 5 .debug 00000040 0000000000172260 0000000000172260 000ced20 2**0 > CONTENTS, READONLY, DEBUGGING > > If the bootloader is using the EFI handover protocol (rather than > calling the PE entry point), how is it (currently) supposed to know how > much memory to provide beyond the end of the bzImage file? > Since that means you are "bzImage aware" you can look at the fields for this in the bzImage header: init_size, kernel_alignment, relocatable_kernel, min_alignment, and pref_address. (init_size is the important one, obviously, but a misaligned kernel may require additional space for adjustment.) -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
