first_time_install.sh applies patches/rpi-rgb-led-matrix/0001-bulk-setimage.patch just before building the Python binding and reverts it afterwards (and from the EXIT trap), so the submodule stays at its pinned commit. The patch copies each image row with one bulk FrameCanvas::SetPixels call and writes the bit planes branch-free: on a 512x64 Pi 4 the frame copy went from 6.57 ms to 2.21 ms. A patch that no longer applies is reported and skipped. Existing installs get it on a rebuild (RPI_RGB_FORCE_REBUILD=1).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The pinned rpi-rgb-led-matrix commit emits the ARMv7-only `dmb ishst`
instruction in lib/rp1/rp1_rio_backend.cc, guarded only by __arm__, so the
build fails on every ARMv6 board ("selected processor does not support
`dmb ishst' in ARM mode"). Bump the pin to upstream 1ee4f76, which merges
12d839f (guard on __ARM_ARCH >= 7) plus docs only.
The installer also needed two changes for that bump to reach anyone:
- git pull never moves an existing submodule checkout, so a device that
already failed would keep building the broken commit. The build step now
moves the checkout forward to the pin — never backward or sideways (a
`git submodule update --remote` checkout is left alone), and never fatal.
- The submodule git commands ran as root on the user's clone (git's SUDO_UID
exemption allows it), leaving .git/modules/rpi-rgb-led-matrix-master
root-owned and the user unable to run git in it. They now run as the
project directory's owner, and root-owned leftovers are handed back.
Root-owned installs keep running as root.
test/test_install_rgb_checkout.py covers the non-root sync scenarios under
the installer's strict mode, checks that every called _helper is defined
before use, and pins the one-shot-install.sh -> first_time_install.sh
contract. Verified the tests fail on five deliberate mutations. Root/owner
scenarios were exercised manually under WSL Ubuntu, and the library was
cross-compiled for arm1176jzf-s at both pins (old: rp1_rio_backend.cc fails
at line 120; new: 16/16 sources compile).
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
