glibc/sysdeps/unix/sysv/linux/arm/aeabi_read_tp.S

56 lines
2.1 KiB
ArmAsm

/* Copyright (C) 2005-2017 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.
In addition to the permissions in the GNU Lesser General Public
License, the Free Software Foundation gives you unlimited
permission to link the compiled version of this file with other
programs, and to distribute those programs without any restriction
coming from the use of this file. (The GNU Lesser General Public
License restrictions do apply in other respects; for example, they
cover modification of the file, and distribution when not linked
into another program.)
Note that people who make modified versions of this file are not
obligated to grant this special exception for their modified
versions; it is their choice whether to do so. The GNU Lesser
General Public License gives permission to release a modified
version without this exception; this exception also makes it
possible to release a modified version which carries forward this
exception.
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>
/* GCC will emit calls to this routine under -mtp=soft. Linux has an
equivalent helper function (which clobbers fewer registers than
a normal function call) in a high page of memory; tail call to the
helper. */
.hidden __aeabi_read_tp
ENTRY (__aeabi_read_tp)
#ifdef ARCH_HAS_HARD_TP
mrc p15, 0, r0, c13, c0, 3
bx lr
#elif defined(__thumb2__)
movw r0, #0x0fe0
movt r0, #0xffff
bx r0
#else
mov r0, #0xffff0fff
sub pc, r0, #31
#endif
END (__aeabi_read_tp)