nuttx/Documentation/platforms
Marco Casaroli f565c81c3b Documentation, boards/rp23xx: Describe FDPIC and add a test configuration.
Documentation/os/binfmt/fdpic.rst covers what an FDPIC module is and what
it adds over the position independent ELF support already in the tree, how
the loader places one, where shared libraries come from and how they are
found, which entry points resolve a function descriptor and the rules for
adding another, and how to build a module and a library.  A comparison
table places it against NXFLAT and PIC ELF, and the reference section
records the object layout and the relocations.

pimoroni-pico-2-plus:xipfs-fdpic is the configuration the series was tested
on: xipfs on the board's QSPI flash, the ELF loader with CONFIG_FDPIC, and
apps/examples/fdpicxip with apps/testing/fs/xipfs.

CONFIG_DEFAULT_TASK_STACKSIZE is 4096 there rather than the rp23xx default
of 2048.  Both sides of the loader need it: a module that calls into the
firmware's printf family overflows 2048, and with no MPU that is a lockup
rather than a diagnostic.  CONFIG_ELF_STACKSIZE follows it, and
apps/testing/fs/xipfs sizes its own task from it.

CONFIG_HAVE_CXXINITIALIZE is set because crt0 runs the constructors of a
module only with it, and the xipfs suite checks that they ran.

Assisted-by: Claude Code:claude-opus-5-5
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
2026-10-08 14:24:34 -03:00
..
arm Documentation, boards/rp23xx: Describe FDPIC and add a test configuration. 2026-10-08 14:24:34 -03:00
arm64 Documentation/qemu-armv8a: Note fork() and the semihosting flag. 2026-10-08 09:35:07 -03:00
avr Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
ceva
hc Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
mips Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
misoc Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
or1k Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
renesas Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
risc-v Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
sim Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
sparc Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
tricore Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
x86 Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
x86_64 Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
xtensa Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
z16 Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
z80 Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00
index.rst Documentation: brand new layout for NuttX documentation. 2026-10-08 01:40:54 +08:00