https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107032
Christophe Lyon <clyon at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |clyon at gcc dot gnu.org --- Comment #1 from Christophe Lyon <clyon at gcc dot gnu.org> --- At quick glance, I think this is caused by the definition of CLEAR_INSN_CACHE in gcc/config/arm/uclinux-eabi.h: /* Clear the instruction cache from `beg' to `end'. This makes an inline system call to SYS_cacheflush. */ #undef CLEAR_INSN_CACHE #define CLEAR_INSN_CACHE(BEG, END) \ { \ register unsigned long _beg __asm ("a1") = (unsigned long) (BEG); \ register unsigned long _end __asm ("a2") = (unsigned long) (END); \ register unsigned long _flg __asm ("a3") = 0; \ register unsigned long _scno __asm ("r7") = 0xf0002; \ __asm __volatile ("swi 0x0 @ sys_cacheflush" \ : "=r" (_beg) \ : "0" (_beg), "r" (_end), "r" (_flg), "r" (_scno)); \ } which makes explicit use of r7. This code has been like that since it was committed in 2007.... So I suspect nobody ever tried to build this configuration.