genode

History

Norman Feske 7f73e5e879 base: hide internals of the Thread API This patch moves details about the stack allocation and organization the base-internal headers. Thereby, I replaced the notion of "thread contexts" by "stacks" as this term is much more intuitive. The fact that we place thread-specific information at the bottom of the stack is not worth introducing new terminology. Issue #1832		2016-03-07 12:34:46 +01:00
..
include	ldso: Support for RISC-V	2016-02-26 11:36:51 +01:00
spec	ldso: Support for RISC-V	2016-02-26 11:36:51 +01:00
startup
debug.cc
dependency.cc
exception.cc
file.cc
linker.ld
linux-32.ld
main.cc	base: hide internals of the Thread API	2016-03-07 12:34:46 +01:00
README
shared_object.cc
symbol.map
test.cc

README

This directory contains Genode's dynamic linker (ldso)


Usage
-----

To build a shared library instead of a regular static library, you just need to
declare 'SHARED_LIB = yes' in the library-description file.  When doing so, a
'<libname>.lib.so' file will be generated and installed in the
'<build-dir>/bin/' directory.  For building an executable that uses a shared
library, no special precautions are needed. The build system will automatically
detect the use of shared libraries, concludes that the binary must be
dynamically linked, and will use the correct linker script.  When loading a
dynamically linked program, the dynamic linker 'ldso.lib.so' and all used shared
objects must be loaded as well.

The linker can be configured through the '<config>' node when loading a dynamic
binary. Currently there are to configurations options, 'ld_bind_now="yes"'
causes the linker to resolve all symbol references on program loading.
'ld_verbose="yes"' outputs library load informations before starting the
program.

Configuration snippet:

!<!-- bind immediately, no library informations -->
!<start name="dynamic_binary">
!  <resource name="RAM" quantum="1M" />
!  <config ld_bind_now="yes" ld_verbose="no">
!  </config>
!</start>

Debugging dynamic binaries with GDB stubs
-----------------------------------------

! # go to directory containing the binaries
! cd <build/dir>/bin
!
! # start GDB with binary to debug
! gdb <binary name>
!
! # break in main routine
! b main
!
! # inspect loaded shared libraries
! info sharedlibrary
!
! # load shared symbols of shared libraries (if not already loaded)
! share
!
! # from here you can debug within libraries

:Known issues:

GDB 7.2 has a regression bug in its line information parser. These issue has
been fixed with version 7.3.