genode/repos/base/src/lib/ldso
Norman Feske cfdbccc5c2 Remove blocking calls from root and parent RPCs
This is a redesign of the root and parent interfaces to eliminate
blocking RPC calls.

- New session representation at the parent (base/session_state.h)
- base-internal root proxy mechanism as migration path
- Redesign of base/service.h
- Removes ancient 'Connection::KEEP_OPEN' feature
- Interface change of 'Child', 'Child_policy', 'Slave', 'Slave_policy'
- New 'Slave::Connection'
- Changed child-construction procedure to be compatible with the
  non-blocking parent interface and to be easier to use
- The child's initial LOG session, its binary ROM session, and the
  linker ROM session have become part of the child's envirenment.
- Session upgrading must now be performed via 'env.upgrade' instead
  of performing a sole RPC call the parent. To make RAM upgrades
  easier, the 'Connection' provides a new 'upgrade_ram' method.

Issue #2120
2016-11-25 16:06:42 +01:00
..
include Remove blocking calls from root and parent RPCs 2016-11-25 16:06:42 +01:00
spec Clean ldso from using deprecated APIs 2016-11-08 15:26:32 +01:00
startup base: avoid use of deprecated base/printf.h 2016-08-29 17:27:10 +02:00
debug.cc Clean ldso from using deprecated APIs 2016-11-08 15:26:32 +01:00
dependency.cc Clean ldso from using deprecated APIs 2016-11-08 15:26:32 +01:00
exception.cc Clean ldso from using deprecated APIs 2016-11-08 15:26:32 +01:00
linker.ld base: Genode's dynamic linker 2014-11-12 14:44:15 +01:00
linux-32.ld ldso: Make truly self relocatable 2015-12-10 13:16:25 +01:00
main.cc ldso: initialize ELF object before relocating 2016-11-25 15:27:28 +01:00
README base: Genode's dynamic linker 2014-11-12 14:44:15 +01:00
shared_object.cc Clean ldso from using deprecated APIs 2016-11-08 15:26:32 +01:00
symbol.map Supplement base/log.h with raw output function 2016-06-22 12:21:42 +02:00
test.cc base: Genode's dynamic linker 2014-11-12 14:44:15 +01:00

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.