nuttx/tools/.gitignore
Marco Casaroli 8d08885d0f tools/nxflat: Import the NXFLAT thunk generator.
An NXFLAT module reaches the base firmware through a "thunk" file: one
assembly stub per imported function, generated by mknxflat.  That tool
has always lived outside this repository, in the NuttX buildroot NXFLAT
toolchain, so building an NXFLAT module needs a separate checkout and a
separate build of a tool that links against libbfd.

libbfd is why it stayed out.  It is GPL, which an Apache project cannot
depend on, and it is awkward to obtain besides -- a stock binutils
install often ships libbfd without the libiberty it needs to link.  But
the dependency was never deep.  mknxflat used libbfd for eight calls,
all of them opening the file and walking the symbol table; it never
relocates or rewrites anything.  That is replaced here by reading the
ELF symbol table directly, which removes the dependency outright and
costs about a hundred lines.

The emitted text is unchanged.  The format strings live in the .def
files, which are carried here byte-for-byte from upstream, and the
selection rule for what becomes a thunk is the upstream one: everything
undefined that is not explicitly an object.  Symbol typing cannot be
trusted for this -- imported functions are routinely emitted as
STT_NOTYPE rather than STT_FUNC, while a weakly defined object does
appear as an undefined object -- so the test is on what a symbol is not.

Upstream chose the instruction set at compile time through an "arch"
symlink pointing at either arm/ or thumb2/.  A symlink cannot be carried
in the repository, and one host binary has to serve boards of both
flavours, since lpc31xx is ARM while lpc17xx, tiva, stm32f1 and rp23xx
are Thumb-2.  That choice becomes a runtime "-a" option.  The "-f"
option, which read further command line arguments from a file, is
dropped; nothing in the tree used it.

This commit changes no output.  Against the upstream tool, for both
architectures, with and without -w, over modules exercising the plain,
weak and non-returning thunk paths, the generated thunk files are
byte-identical.

Assisted-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
2026-08-06 01:38:23 +08:00

25 lines
276 B
Text

/b16
/bdf-converter
/cmpconfig
/configure
/convert-comments
/detab
/gencromfs
/initialconfig
/mkconfig
/mknxflat
/mkdeps
/cnvwindeps
/logparser
/lowhex
/mksymtab
/mksyscall
/mkversion
/mkpasswd
/nxstyle
/rmcr
/incdir
/.k2h-body.dat
/.k2h-apndx.dat
/jlink-nuttx.so
__pycache__