Toolchain.defs adds --fixed-r10 to CFLAGS under CONFIG_PIC, but nearly
every board Make.defs includes that file and then assigns
CFLAGS := $(ARCHCFLAGS) $(ARCHOPTIMIZATION) $(ARCHCPUFLAGS) ...
with ':=', which discards it. 266 of the 269 ARM board files assign
CFLAGS that way; the remaining three delegate to a shared makefile that
does the same thing.
The flag is what keeps the base firmware from allocating r10, the
register a PIC module reaches its own data through. Losing it is silent
and the symptom is remote from the cause: the build succeeds, and only a
callback from base firmware into module code -- qsort() with a module
comparison function is the standard case -- misbehaves, reading its data
through a register the firmware has since felt free to reuse.
Adding it to ARCHCFLAGS puts it on the far side of that ':=', which
re-expands ARCHCFLAGS, so every board picks it up with no board changes
at all.
A module is the other side of the --fixed-r10 contract: it gets r10 via
-mpic-register=r10, and GCC rejects both on one command line with
"unable to use 'r10' for PIC register". Every ARM board carried the
same three lines to set that up:
ARCHPICFLAGS = -fpic -msingle-pic-base -mpic-register=r10
CPICFLAGS = $(ARCHPICFLAGS) $(CFLAGS)
CXXPICFLAGS = $(ARCHPICFLAGS) $(CXXFLAGS)
They move to arch/arm/src/common/Toolchain.defs, which also filters
--fixed-r10 back out of CPICFLAGS, CXXPICFLAGS, CELFFLAGS and
CXXELFFLAGS in one place instead of each board having to know about the
interaction. ARCHPICFLAGS uses '?=' and the derived flags use deferred
'=', so a board can still override or append after including the file,
and CFLAGS is whatever the board finally set it to.
Two boards keep a definition because they genuinely differ: am67 adds
-ffixed-r10 and tiva conditionally adds -mno-pic-data-is-text-relative.
tlsr82 previously appended -fpic to an unset variable, so only -fpic
ever reached its compiler; it now inherits the standard set, verified
against tc32-elf-gcc 4.5.1.tc32-elf-1.5 (Telink TC32 v2.0), whose
ARM-derived backend honors -msingle-pic-base and -mpic-register=r10.
The mps2, mps3, qemu-armv7a, qemu-armv7r, fvp and mcx-nxxx families
referenced ARCHPICFLAGS without ever defining it, so their CPICFLAGS
carried no PIC flags at all; they get the standard set too.
Also adds the missing space in
CXXELFFLAGS = $(CXXFLAGS)-fvisibility=hidden -mlong-calls
which ran the last token of CXXFLAGS into -fvisibility=hidden, yielding
a single malformed token such as -DNDEBUG-fvisibility=hidden.
Also exempts the pre-existing "*.siz" gsize comment in Toolchain.defs
from codespell, which reads "siz" as a misspelling and fires for any
patch touching the file, since checkpatch scans whole files rather than
changed lines.
Before, with CONFIG_PIC=y: CFLAGS has --fixed-r10: NO
After: CFLAGS has --fixed-r10: YES
CPICFLAGS/CELFFLAGS: filtered out
Assisted-by: Claude Code:claude-opus-4-8
Assisted-by: Claude Code:claude-fable-5
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
Added initial support for Seeed Studio XIAO RA4M1 Board. Initial
support to NuttShell via Serial, gpio and userleds. Also two
configurations is available: nsh for basic NuttShell access and
combo for gpio and userleds.
Signed-off-by: Rodrigo Sim <rcsim10@gmail.com>
