| /* Create new context. RISC-V version. |
| Copyright (C) 2001-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| 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 <sysdep.h> |
| #include <sys/asm.h> |
| #include <sys/ucontext.h> |
| #include <stdarg.h> |
| #include <assert.h> |
| |
| void |
| __makecontext (ucontext_t *ucp, void (*func) (void), int argc, |
| long int a0, long int a1, long int a2, long int a3, long int a4, |
| ...) |
| { |
| extern void __start_context (void) attribute_hidden; |
| long int i, sp; |
| |
| _Static_assert (REG_NARGS == 8, "__makecontext assumes 8 argument registers"); |
| |
| /* Set up the stack. */ |
| sp = ((long int) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size) & ALMASK; |
| |
| /* Set up the register context. |
| ra = s0 = 0, terminating the stack for backtracing purposes. |
| s1 = the function we must call. |
| s2 = the subsequent context to run. */ |
| ucp->uc_mcontext.__gregs[REG_RA] = 0; |
| ucp->uc_mcontext.__gregs[REG_S0] = 0; |
| ucp->uc_mcontext.__gregs[REG_S1] = (long int) func; |
| ucp->uc_mcontext.__gregs[REG_S2] = (long int) ucp->uc_link; |
| ucp->uc_mcontext.__gregs[REG_SP] = sp; |
| ucp->uc_mcontext.__gregs[REG_PC] = (long int) &__start_context; |
| |
| /* Put args in a0-a7, then put any remaining args on the stack. */ |
| ucp->uc_mcontext.__gregs[REG_A0 + 0] = a0; |
| ucp->uc_mcontext.__gregs[REG_A0 + 1] = a1; |
| ucp->uc_mcontext.__gregs[REG_A0 + 2] = a2; |
| ucp->uc_mcontext.__gregs[REG_A0 + 3] = a3; |
| ucp->uc_mcontext.__gregs[REG_A0 + 4] = a4; |
| |
| if (__glibc_unlikely (argc > 5)) |
| { |
| va_list vl; |
| va_start (vl, a4); |
| |
| long reg_args = argc < REG_NARGS ? argc : REG_NARGS; |
| for (i = 5; i < reg_args; i++) |
| ucp->uc_mcontext.__gregs[REG_A0 + i] = va_arg (vl, long); |
| |
| long int stack_args = argc - reg_args; |
| if (stack_args > 0) |
| { |
| sp = (sp - stack_args * sizeof (long int)) & ALMASK; |
| ucp->uc_mcontext.__gregs[REG_SP] = sp; |
| for (i = 0; i < stack_args; i++) |
| ((long int *) sp)[i] = va_arg (vl, long int); |
| } |
| |
| va_end (vl); |
| } |
| } |
| |
| weak_alias (__makecontext, makecontext) |