Apache NuttX is a mature, real-time embedded operating system (RTOS) https://nuttx.apache.org/
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Marco Casaroli 0518ccb9ca libs/libc/elf, binfmt: Describe the GOT by base and size, not by index.
gotindex named the .got section header, and every user then reached through
shdr[] for what it actually wanted.  Only one of the five wanted the index.

gotbase and gotsize say it directly.  gotsize is the extent of .got and is
also what says the object has one, and gotbase is where the GOT ended up:
the placed address of .got for an ordinary object, or DT_PLTGOT for an FDPIC
one, which libelf_bind() already reads.  Both are set in libelf_loadfile(),
after the sections are placed, so gotbase is the address the object will be
read at rather than the one it was linked for.

The GOT walk in libelf_loadfile() now runs only when there is a base, which
also keeps it off an FDPIC object.  An FDPIC object's sections are never
placed, so .got carried a link time sh_addr there, and the walk read and
wrote through it.  Its GOT is relocated through its own relocations.

The check that gates libelf_xipacquire() runs before the load, when neither
field is set, so it looks the section up by name.  It hands the index it
found to libelf_loadfile(), which is the only reason that function takes
one: the object is searched once, not twice.

One behaviour changes: a .got that exists but is empty now reads as no GOT.
There is nothing for any of the five users to do with an empty one.

Built for pimoroni-pico-2-plus with CONFIG_PIC, CONFIG_ELF and
CONFIG_LIBC_ELF, and for mps3-an547:bl, which is the board that read the
index.  Run on QEMU with mps3-an547:picostest, which loads PIC ELF modules
from a romfs: hello prints, and ostest reaches the timed mutex test, the
same as before the change.

Assisted-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
2026-09-08 16:31:16 -03:00
.github tools/ci: remove obsolete testrun harness 2026-09-02 11:44:23 -03:00
arch libs/libc/elf: Place an FDPIC object's segments independently. 2026-09-08 16:31:16 -03:00
audio audio: limit the buffer count guard to shared ring requests 2026-08-05 07:58:53 +02:00
binfmt libs/libc/elf, binfmt: Describe the GOT by base and size, not by index. 2026-09-08 16:31:16 -03:00
boards libs/libc/elf, binfmt: Describe the GOT by base and size, not by index. 2026-09-08 16:31:16 -03:00
cmake cmake: parse EXTRAFLAGS with separate_arguments. 2026-09-01 09:19:27 +08:00
crypto tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-07-28 21:26:03 -03:00
Documentation Documentation/rp2040: document fastboot_usb config for waveshare boards 2026-09-08 08:22:37 -03:00
drivers drivers/mtd/gd25.c: ensure the device is not in power down mode 2026-09-08 08:59:33 +08:00
dummy
fs libs/libc/elf: Place an FDPIC object's segments independently. 2026-09-08 16:31:16 -03:00
graphics graphics/nxterm: consume SGR escape sequences 2026-08-23 10:46:02 +08:00
include libs/libc/elf, binfmt: Describe the GOT by base and size, not by index. 2026-09-08 16:31:16 -03:00
libs libs/libc/elf, binfmt: Describe the GOT by base and size, not by index. 2026-09-08 16:31:16 -03:00
mm cmake: Use NUTTX(_DIR/_BIN_DIR) instead CMAKE(_SRC_DIR/_BIN_DIR) 2026-08-09 11:13:08 -03:00
net net/tcp: add configurable delayed ACK threshold 2026-09-08 09:00:19 +08:00
openamp cmake: Use NUTTX(_DIR/_BIN_DIR) instead CMAKE(_SRC_DIR/_BIN_DIR) 2026-08-09 11:13:08 -03:00
pass1 tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-07-28 21:26:03 -03:00
sched arch/atomic: remove up_testset in spinlock 2026-09-08 08:58:54 +08:00
syscall fs: rename PSEUDOFS_SOFTLINKS to FS_LINKS 2026-08-27 01:12:33 +08:00
tools tools/pynuttx: Update the preemption field annotations. 2026-09-07 21:06:53 +08:00
video video/videomode: Fix EDID parsing and formatting of video mode dumps 2026-08-29 11:09:11 -03:00
wireless wireless/bluetooth: fix inverted MTU cap in bt_conn_send() 2026-08-30 10:48:18 -03:00
.asf.yaml github: master branch protection tune. 2025-05-07 18:37:13 -05:00
.codespell-ignore-lines arch/arm: Reserve r10 via ARCHCFLAGS and hoist the PIC module flags. 2026-07-24 23:09:08 +08:00
.codespellrc Revert "zbus: Add linker support and documentation for the zbus port" 2026-08-30 10:45:19 -03:00
.editorconfig .editorconfig: fix character encoding property specification 2025-11-28 19:12:13 +08:00
.gitignore boards/risc-v/eic7700x: Adopt the common board layout. 2026-08-19 01:40:57 +08:00
.gitmessage docs/contributing: Add a commit message template 2025-06-03 17:33:24 +08:00
.pre-commit-config.yaml pre-commit: enable codespell checks 2025-05-05 12:34:39 +08:00
.yamllint
AUTHORS AUTHORS: add Jorge Guzman 2026-08-25 08:43:13 -04:00
CMakeLists.txt arch, boards, cmake: Build C++ ELF modules without __cxa_atexit. 2026-09-04 15:44:24 -03:00
CONTRIBUTING.md contributing: Add requirement for 'Assisted-by' commit field 2026-07-12 09:42:28 +08:00
INVIOLABLES.md
Kconfig include/nuttx: Add link-time iterable sections infrastructure 2026-08-27 01:04:05 +08:00
LICENSE libs/libdsp: Add Matrix operations 2026-07-11 14:55:59 -03:00
Makefile !boards: enforce secure ROMFS passwd and TEA key setup 2026-07-09 22:41:11 +08:00
NOTICE
README.md ci/testing: Add MemBrowse Integration 2026-06-18 12:07:41 -03:00
ReleaseNotes Documentation: move ReleaseNotes 2023-09-26 20:41:00 +08:00

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Apache NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the primary governing standards in NuttX are POSIX and ANSI standards. Additional standard APIs from Unix and other common RTOSs (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()).

For brevity, many parts of the documentation will refer to Apache NuttX as simply NuttX.

Getting Started

First time on NuttX? Read the Getting Started guide! If you don't have a board available, NuttX has its own simulator that you can run on terminal.

Documentation

You can find the current NuttX documentation on the Documentation Page.

Alternatively, you can build the documentation yourself by following the Documentation Build Instructions.

The old NuttX documentation is still available in the Apache wiki.

Supported Boards

NuttX supports a wide variety of platforms. See the full list on the Supported Platforms page.

Contributing

If you wish to contribute to the NuttX project, read the Contributing guidelines for information on Git usage, coding standard, workflow and the NuttX principles.

License

The code in this repository is under either the Apache 2 license, or a license compatible with the Apache 2 license. See the License Page for more information.