mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-03 02:11:08 +00:00
78 lines
2.4 KiB
C
78 lines
2.4 KiB
C
/* Create new context. OpenRISC version.
|
|
Copyright (C) 2022-2024 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
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <sysdep.h>
|
|
#include <stdarg.h>
|
|
#include <stdint.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 -> | parameters 7 to n |
|
|
+-----------------------+
|
|
|
|
The registers are set up like this:
|
|
r3-r8 : parameters 1 to 6
|
|
r14 : uc_link
|
|
r1 : stack pointer
|
|
r2 : frame pointer, set to NULL
|
|
*/
|
|
void
|
|
__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...)
|
|
{
|
|
extern void __startcontext (void);
|
|
unsigned long int *sp;
|
|
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) & -4L);
|
|
|
|
/* Keep uc_link in r14. */
|
|
ucp->uc_mcontext.__gprs[14] = (uintptr_t) ucp->uc_link;
|
|
/* Return address points to function __startcontext. */
|
|
ucp->uc_mcontext.__gprs[9] = (uintptr_t) &__startcontext;
|
|
/* Frame pointer is null. */
|
|
ucp->uc_mcontext.__gprs[2] = (uintptr_t) 0;
|
|
/* Restart in user-space starting at 'func'. */
|
|
ucp->uc_mcontext.__gprs[11] = (uintptr_t) func;
|
|
/* Set stack pointer. */
|
|
ucp->uc_mcontext.__gprs[1] = (uintptr_t) sp;
|
|
|
|
va_start (ap, argc);
|
|
for (i = 0; i < argc; ++i)
|
|
if (i < 6)
|
|
ucp->uc_mcontext.__gprs[i + 3] = va_arg (ap, unsigned long int);
|
|
else
|
|
sp[i - 6] = va_arg (ap, unsigned long int);
|
|
|
|
va_end (ap);
|
|
}
|
|
|
|
weak_alias (__makecontext, makecontext)
|