Commit Graph

8 Commits

Author SHA1 Message Date
Norman Feske
ff28ed0f8c base: avoid superfluous postprocessing of ldso
Even though the binary patching of ldso must be performed only once,
this postprocessing step was executed on each run because the
postprocess.tag rule is phony (the tag file is never created).
This patch removes this phony behavior by creating the tag file.

Issue #3974
2021-01-25 14:00:43 +01:00
Norman Feske
a98f78afd9 ldso: avoid 'dd' output in build log
This patch is a follow-up commit for "ld: load dynamic linker at static
address on Linux". It suppresses the stderr output of 'dd' when marking
the ELF binary as executable.

Issue #3479
2019-08-28 14:18:45 +02:00
Sebastian Sumpf
2fc6cedcc0 ld: load dynamic linker at static address on Linux
* move stack area to static address at beginning of binary
* set ELF type of linker from shared to executable

fixes #3479
2019-08-21 13:25:25 +02:00
Norman Feske
80ef5fa73c Enable use of 'check_abi' in build system
This patch invokes the 'check_abi' tool for each shared library that
implements an ABI.

Issue #2639
2018-01-17 12:14:42 +01:00
Christian Helmuth
ddfd3c0d7e linux: stack-area handling with recent Linux kernels
We moved the stack-area segment 128 MiB behind text and data to comply
with assumptions in the kernel ELF loader.

This commit also reenables static binaries on linux and removes the
unused stack_area.stdlib.ld script.

Fixes #2521
2017-10-05 17:40:00 +02:00
Norman Feske
4da52517c1 Simpify startup of dynamically linked binaries
This patch removes the component_entry_point library, which used to
proved a hook for the libc to intercept the call of the
'Component::construct' function. The mechansim has several shortcomings
(see the discussion in the associated issue) and was complex. So we
eventually discarded the approach in favor of the explicit handling of
the startup.

A regular Genode component provides a 'Component::construct' function,
which is determined by the dynamic linker via a symbol lookup.
For the time being, the dynamic linker falls back to looking up a 'main'
function if no 'Component::construct' function could be found.

The libc provides an implementation of 'Component::construct', which
sets up the libc's task handling and finally call the function
'Libc::Component::construct' from the context of the appllication task.
This function is expected to be provided by the libc-using application.
Consequently, Genode components that use the libc have to implement the
'Libc::Component::construct' function.

The new 'posix' library provides an implementation of
'Libc::Component::construct' that calls a main function. Hence, POSIX
programs that merely use the POSIX API merely have to add 'posix' to the
'LIBS' declaration in their 'target.mk' file. Their execution starts at
'main'.

Issue #2199
2017-01-13 13:06:52 +01:00
Norman Feske
9ea4a491d6 ld: generate symbol map from base/lib/symbols/ld
This patch removes the manually maintained symbol map from the dynamic
linker. This way, the symbol map stays in sync with the ABI and - more
importantly - no longer uses wildcards. So the symbols exported by the
dynamic linker are strictly limited by the ABI.

Issue #2190
2016-12-23 16:53:17 +01:00
Norman Feske
f54c85e045 Genode application binary interface (ABI)
This patch decouples the kernel-specific implementation of the dynamic
linker from its kernel-agnostic binary interface. The name of the
kernel-specific dynamic linker binary now corresponds to the kernel,
e.g., 'ld-linux.lib.so' or 'ld-nova.lib.so'. Applications are no longer
linked directly against a concrete instance of the dynamic linker but
against a shallow stub called 'ld.lib.so'. This stub contains nothing
but the symbols provided by the dynamic linker. It thereby represents
the Genode ABI.

At system-integration time, the kernel-specific run/boot_dir back ends
integrate the matching the kernel-specific variant of the dynamic linker
as 'ld.lib.so' into the boot image.

The ABI symbol file for the dynamic linker is located at
'base/lib/symbols/ld'. It contains the joint ABI of all supported
architectures. The new utility 'tool/abi_symbols' eases the creation of
such an ABI symbol file for a given shared library. Its result should be
manually inspected and edited as needed.

The patch removes the 'syscall' library from 'base_libs.mk' to avoid
polluting the kernel-agnostic ABI with kernel-specific interfaces.

Issue #2190
Issue #2195
2016-12-23 16:50:28 +01:00