On 2026-04-28 18:04:47+0100, Stafford Horne wrote: > On Tue, Apr 28, 2026 at 05:48:51PM +0200, Thomas Weißschuh wrote: > > Add support for OpenRISC / or1k to nolibc. > > > > _start() uses the same wrapper construct as in arch-sh.h. > > libgcc is necessary as OpenRISC is missing 64-bit multiplication. > > There are a few minor issues with this patch.
Thanks for taking a look! > Could you give any background for this? What are you working on? > Just getting more coverage in the test suite? I have no specific goal. In general I'd like for nolibc to support all architectures which are supported by Linux. > Do you have any results for or1k, considering one of the issues I > highlighted before I am not sure this will compile as is. This compiled fine for me and ran the full nolibc testsuite. More details below. With "highlighted before", do you mean "below"? > > Signed-off-by: Thomas Weißschuh <[email protected]> > > --- > > tools/include/nolibc/Makefile | 2 +- > > tools/include/nolibc/arch-openrisc.h | 176 > > +++++++++++++++++++++++++ > > tools/include/nolibc/arch.h | 2 + > > tools/testing/selftests/nolibc/Makefile.nolibc | 5 + > > tools/testing/selftests/nolibc/run-tests.sh | 4 +- > > 5 files changed, 187 insertions(+), 2 deletions(-) (...) > > +#define __nolibc_syscall0(num) > > \ > > +({ > > \ > > + register long _num __asm__ ("r11") = (num); \ > > + register long _ret __asm__ ("r11"); \ > > + \ > > + __asm__ volatile ( \ > > + "l.sys 1\n" \ > > + "l.nop\n" \ > > We do not need l.nop for l.sys instructions. They do not have a delay-slot > line > branches. Ack, I'll remove them. > > + : "=r"(_ret) \ > > + : "r"(_num) \ > > + : "r3", "r4", "r5", "r6", "r7", "r8", \ > > + _NOLIBC_SYSCALL_CLOBBERLIST \ > > + ); \ > > + _ret; \ > > +}) (...) > > +#ifndef NOLIBC_NO_RUNTIME > > +/* startup code */ > > +void _start_wrapper(void); > > +void __attribute__((weak,noreturn)) > > +__nolibc_entrypoint __nolibc_no_stack_protector > > +_start_wrapper(void) > > +{ > > + __asm__ volatile ( > > + ".global _start\n" /* The C function will have a > > prologue, */ > > + ".type _start, @function\n" /* corrupting "sp" > > */ > > + ".weak _start\n" > > + "_start:\n" > > + > > + "l.or r3,sp,sp\n" /* save stack pointer to 3, as > > arg1 of _start_c */ > > What is sp here? There is no sp alias in OpenRISC, should it be r1? Does > this > compile? It compiles and works with my fairly modern GCC. It is translated to 'r1'. If it is not idiomatic, I'll change it to r1. > > > + "l.jal _start_c\n" /* transfer to c runtime > > */ > > + "l.nop\n" > > The l.or can go in the delay slot. Ack. > Also, preferrably we use spaces between args, and a space to indicate a delay > slot e.g. > > "l.jal _start_c\n" > "l.or r3, r1, r1\n" I'd prefer to keep this aligned with the rest of nolibc instead of aligning it with the arch/openrisc/ code. > > + > > + ".size _start, .-_start\n" > > + ); > > + __nolibc_entrypoint_epilogue(); > > +} > > +#endif /* NOLIBC_NO_RUNTIME */ (...) > The rest looks ok to me. Thanks! Thomas
