Marco Casaroli db011db3ac arch/arm: Reserve r10 via ARCHCFLAGS and hoist the PIC module flags. ... 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>		2026-07-24 23:09:08 +08:00
..
kwikstik-k40.ld	boards/arm/kinetis: migrate to SPDX identifier	2024-11-10 01:12:34 +08:00
Make.defs	arch/arm: Reserve r10 via ARCHCFLAGS and hoist the PIC module flags.	2026-07-24 23:09:08 +08:00