ricardgb opened a new pull request, #19401:
URL: https://github.com/apache/nuttx/pull/19401
## Summary
The pico-sdk-derived rp23xx linker scripts place `.got`/`.got.plt` as
**orphan
sections after the `.data` output section**, so the boot-time `.data` copy —
which runs to `_edata` — never copies the GOT into RAM. Any
position-independent
(`-fPIC`) object linked into an application then reads an **uninitialised
GOT full
of NULLs**: the first GOT-indirected access branches to 0 and the board
hardfaults
before `main()`.
This is not hypothetical — a `-fPIC` static library is enough. In my case a
NuttX
app linking a `-fPIC` `liboqs.a` (whose SHA3 dispatch reads its function
pointers
through the GOT) wedged the board deterministically on its first crypto call.
The fix folds `*(.got)`/`*(.got.plt)` into the `.data{}` section, before
`_edata`,
in all three boot-mode scripts (`memmap_default` / `memmap_copy_to_ram` /
`memmap_no_flash`) for every rp23xx board, so the GOT is initialised in RAM
by the
standard startup copy.
## Impact
- Fixes a boot-time hardfault for any `-fPIC` library linked into an rp23xx
app.
- **No effect on non-PIC images** — the GOT is empty, so the added sections
copy
zero bytes.
- Applies uniformly to `raspberrypi-pico-2`, `xiao-rp2350` and
`pimoroni-pico-2-plus`.
## Testing
Reproduced and fixed on a Raspberry Pi Pico 2 W. With the original scripts,
an app
linking a `-fPIC` `liboqs.a` hardfaulted on its first hardware crypto call
(traced
to a NULL GOT-indirected dispatch pointer; the ELF showed `.got` landing
exactly at
`_edata`, i.e. outside the copied range). After folding `.got` into `.data`,
the
GOT is populated in RAM and the same app runs correctly.
---
*Disclosure: this change was prepared by an AI agent (Claude Code) at the
direction
of the author, who root-caused and tested it on hardware before submission.*
🤖 Generated with [Claude Code](https://claude.com/claude-code)
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