The linker supports Procedure Linkage Table (PLT)
generation for multiple load regions containing code when in Base
Platform mode (--base_platform).
To turn on PLT generation when in Base Platform mode use --pltgot=. You can use the option option that
generates PLT sequences--pltgot_opts=crosslr to
add entries in the PLT for calls between RELOC load-regions.
PLT generation for multiple Load Regions is only supported for --pltgot=direct.
The --pltgot_opts=crosslr option is useful
when you have multiple load regions that might be moved relative
to each other when the image is dynamically loaded. The linker generates
a PLT for each load region so that calls do not have to be extended
to reach a distant PLT.
Placement of linker generated PLT sections:
When there is only one load region there is one PLT. The linker creates a section called
.pltwith an objectanon$$obj.o.When there are multiple load regions, a PLT section is created for each load region that requires one. By default, the linker places the PLT section in the first execution region containing code. You can override this by specifying the exact PLT section name in the scatter file.
For example, a load region with name
LR Name.plt_with an object ofLR_NAMEanon$$obj.o. To precisely name this PLT section in a scatter file, use the selector:anon$$obj.o(.plt_LR_NAME)
Be aware of the following:
The linker gives an error message if the PLT for load region
LR_NAMELR_NAMEThe linker gives an error message if load region
LR_NAMERELOCand non-RELOCexecution regions. This is because it cannot guarantee that theRELOCexecution regions are able to reach the PLT at run-time.--pltgot=indirectand--pltgot=sbrelare not supported for multiple load regions.
See also- Concepts
- Reference
Linker Reference:
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