/* * Copyright (C) 2016-2017 Andes Technology, Inc. * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball. */ /* Copyright (C) 2011-2013 Free Software Foundation, Inc. Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library. If not, see <http://www.gnu.org/licenses/>. */ #include <stdarg.h> #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <ucontext.h> /* makecontext sets up a stack and the registers for the user context. The stack looks like this: +-----------------------+ | padding as required | +-----------------------+ sp -> | parameter 7-n | +-----------------------+ The registers are set up like this: $r0 .. $r5: parameter 1 to 6 $r6 : uc_link $sp : stack pointer. */ void __makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) { extern void __startcontext (void); unsigned long int *sp; unsigned long *regptr; va_list ap; int i; sp = (unsigned long int *) ((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size); /* Allocate stack arguments. */ sp -= argc < 6 ? 0 : argc - 6; /* Keep the stack aligned. */ sp = (unsigned long int *) (((uintptr_t) sp) & -8L); ucp->uc_mcontext.nds32_r6 = (uintptr_t) ucp->uc_link; ucp->uc_mcontext.nds32_sp = (uintptr_t) sp; ucp->uc_mcontext.nds32_ipc = (uintptr_t) func; ucp->uc_mcontext.nds32_lp = (uintptr_t) &__startcontext; va_start (ap, argc); regptr = &ucp->uc_mcontext.nds32_r0; for (i = 0; i < argc; ++i) if (i < 6) *regptr++ = va_arg (ap, unsigned long int); else sp[i - 6] = va_arg (ap, unsigned long int); va_end (ap); } weak_alias (__makecontext, makecontext)