Fishwaldo opened a new pull request, #3708:
URL: https://github.com/apache/nuttx-apps/pull/3708
## Summary
* `examples/fbcon` does not build in a kernel build. It asks the registry
of built-in applications for the stack size and priority to spawn its
shell with, and a kernel build has no such registry, so the reference
does not resolve.
* A kernel build's programs are ELF files in a filesystem, which is
exactly what the `posix_spawn()` below already handles, PATH search and
all. There is nothing for the registry to tell it.
* fbcon now consults the registry only where there is one, and takes the
stack size and priority from this example's own configuration otherwise.
* Companion to apache/nuttx-apps#3707, which puts libnx on the kernel-build
link line. Both are needed for fbcon specifically; this one is fbcon's
own defect, that one affects every NX application. Neither depends on the
other to be correct, but fbcon needs both to link.
* No related issue filed.
## Impact
* Is new feature added? Is existing feature changed? **NO.** Build fix.
* Impact on user? **YES, positive**, and confined to this example. Where a
builtin registry exists the behaviour is byte-for-byte what it was; the
new path is reached only where the registry does not exist, which is
where fbcon previously did not compile.
* Impact on build? **NO** beyond fbcon compiling where it did not.
* Impact on hardware? **NO.**
* Impact on documentation? **NO.**
* Impact on security? **NO.**
* Impact on compatibility? **NO.**
* Build-mode dependence? **YES, `CONFIG_BUILD_KERNEL` only**, in the sense
that the guarded path is reached only where `CONFIG_BUILTIN` is unset,
which is the kernel-build case. Flat and protected builds keep the
registry lookup unchanged.
## Testing
I confirm that changes are verified on local setup and works as intended:
* Build Host: macOS 26.5.1, arm64 (Apple Silicon), xPack riscv-none-elf-gcc
15.2.0
* Target: RISC-V, ESWIN EIC7700X EVB (downstream board port, not yet
upstream), kernel build, HDMI framebuffer at 1080p60
Testing logs before change, linking `examples/fbcon` with
apache/nuttx-apps#3707 already applied so that libnx is no longer the
obstacle:
```
/Users/fish/github/nuttx/libs/libc/builtin/lib_builtin_forindex.c:56:(.text.builtin_for_index+0x0):
undefined reference to `g_builtin_count'
riscv-none-elf-ld:
/Users/fish/github/nuttx/libs/libc/builtin/lib_builtin_forindex.c:58:(.text.builtin_for_index+0x12):
undefined reference to `g_builtins'
make[3]: *** [/Users/fish/github/apps/bin/fbcon] Error 1
```
Testing logs after change: fbcon builds, starts, and renders its console on
the framebuffer, spawning a shell whose prompt appears on the monitor:
```
[CPU0] display: /dev/fb0 1080p60
##### CMD 1: fbcon &
fbcon [0:100]
##### END 1 (ok, 1.57s)
```
With glyph rendering traced, showing it drawing to the framebuffer:
```
##### CMD 1: fbcon
[CPU2] fbcon_renderglyph: ch=H [48]
[CPU2] fbcon_renderglyph: ch=e [65]
[CPU2] fbcon_renderglyph: ch=l [6c]
[CPU2] fbcon_renderglyph: ch=o [6f]
```
## PR verification Self-Check
* [x] This PR introduces only one functional change.
* [x] I have updated all required description fields above.
* [x] My PR adheres to Contributing Guidelines and Documentation.
* [ ] My PR is still work in progress (not ready for review).
* [x] My PR is ready for review and can be safely merged into a codebase.
---
*Claude (claude-opus-5) assisted with diagnosing this and with authoring the
code comment and this PR description. The commit carries an `Assisted-by:`
tag
per
[CONTRIBUTING.md](https://github.com/apache/nuttx/blob/master/CONTRIBUTING.md)
ยง1.5.*
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
