Relocation base address is always zero also when defining memory regions in linker script

[Johannes Krottmayer]

Hi!

Don't know where to ask this question. Also tried it on
Stackoverflow for a few months, but unfortunately didn't
get an answer. So therefore I try it here. Hope somebody
can clarify my question.

I'm working on a bare-metal project (simple operating
system kernel) targeting AArch64. Currently I have
defined multiple memory regions in my linker script:

MEMORY {
     RAM_LOCORE (rwx) : ORIGIN = 0x0000000041000000, LENGTH = 2M
     RAM_HICORE (rwx) : ORIGIN = 0xFFFF000041000000, LENGTH = 2M
     RAM_LOKERN (rwx) : ORIGIN = 0x0000000041200000, LENGTH = 256M
     RAM_HIKERN (rwx) : ORIGIN = 0xFFFF000041200000, LENGTH = 256M
}

I have implemented relocation support for the type
R_AARCH64_RELATIVE before the kernel starts in assembly.

The calculation for R_AARCH64_RELATIVE should be the following:
Fixed Address = Base Address + Offset + Addend

But I'm wondering why the base address is always zero. Here the
current relocation entries with 'readelf':

Relocati
on section '.rela.dyn' at offset 0x2000 contains 20 entries:
   Offset          Info           Type           Sym. Value    Sym. Name 
+ Addend
0000410001a8  000000000403 R_AARCH64_RELATIV                    41002000
0000410001b0  000000000403 R_AARCH64_RELATIV 
-ffffbedfe8b0
0000410002e0  000000000403 R_AARCH64_RELATIV                    41002000
0000410002e8  000000000403 R_AARCH64_RELATIV                    41003000
0000410002f8  000000000403 R_AARCH64_RELATIV                    41004000
000041000358  000000000403 R_AARCH64_RELATIV                    41005000
000041000360  000000000403 R_AARCH64_RELATIV                    41006000
ffff0000412017c0  000000000403 R_AARCH64_RELATIV 
-ffffaee00000
ffff0000412017c8  000000000403 R_AARCH64_RELATIV 
-ffffaf600000
ffff000041201900  000000000403 R_AARCH64_RELATIV 
-ffffbedec000
ffff000041201908  000000000403 R_AARCH64_RELATIV 
-ffffbedebb04
ffff000041201920  000000000403 R_AARCH64_RELATIV 
-ffffbee00000
ffff000041213008 
 000000000403 R_AARCH64_RELATIV 
-ffffbedf2000
ffff000041213010  000000000403 R_AARCH64_RELATIV 
-ffffbedf0000
ffff000041213018  000000000403 R_AARCH64_RELATIV 
-ffffbedebcf0
ffff000041213020  000000000403 R_AARCH64_RELATIV 
-ffffafe00000
ffff000041213028  000000000403 R_AARCH64_RELATIV 
-ffffbedf1ff0
ffff000041213030  000000000403 R_AARCH64_RELATIV 
-ffffbedefff0
ffff000041213038  000000000403 R_AARCH64_RELATIV 
-ffffbedeb000
ffff000041213040  000000000403 R_AARCH64_RELATIV 
-ffffbedec000

What's missing in my linker script? Can be the base address also defined
in linker script?

-- 
Kind regards,

Johannes K.

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