Dear Robin,
in message 413D346D.2030606@tait.co.nz you wrote:
For example, on powerpc, the hello_world binary is 90% nulls with just a few words on the end.
Yes, ther eis a pretty huge gap between the .sdata2 and .data segments:
-> objdump -h hello_world
hello_world: file format elf32-big
Sections: Idx Name Size VMA LMA File off Algn 0 .text 00000228 00040000 00040000 00010000 2**2 CONTENTS, ALLOC, LOAD, READONLY, CODE 1 .rodata 00000098 00040228 00040228 00010228 2**2 CONTENTS, ALLOC, LOAD, READONLY, DATA 2 .sdata2 00000000 000402c0 000402c0 000102c0 2**2 ^^^^^^^^^^^^^^^^^^ CONTENTS, ALLOC, LOAD, READONLY, DATA 3 .data 00000000 000502c0 000502c0 000102c0 2**0 ^^^^^^^^^^^^^^^^^^ CONTENTS, ALLOC, LOAD, DATA 4 .got2 00000028 000502c0 000502c0 000102c0 2**0 CONTENTS, ALLOC, LOAD, DATA 5 .sdata 00000000 000502e8 000502e8 000102e8 2**2 CONTENTS, ALLOC, LOAD, DATA 6 .sbss 00000000 000502e8 000502e8 000102e8 2**0 CONTENTS 7 .bss 00000000 000502e8 000502e8 000102e8 2**0 ALLOC 8 .comment 0000007a 00000000 00000000 000102e8 2**0 CONTENTS, READONLY ...
How can I truncate this to make the code more space efficient or change the link order to not have this vast embedded block of wasted space?
Use a linker script which optimizes the size of the segments.
It appears to be associated with libgcc so perhaps there is a way of
No, this has nothing to do with libgcc. It's more a question of how you link the image.
forcing these functions to be inlined? Is there a way of avoiding them altogether or perhaps since U-Boot has already included them, maybe more vectors to gain access to them?
This is not the problem.
Best regards,
Wolfgang Denk