newlib/libgloss/sparc_leon/regwin_patch.c

83 lines
2.7 KiB
C

/*
* Copyright (c) 2011 Aeroflex Gaisler
*
* BSD license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <asm-leon/leon.h>
#include <asm-leon/leonstack.h>
#include <asm-leon/asmmacro.h>
extern volatile unsigned int __window_overflow_rettseq[3];
extern volatile unsigned int __window_overflow_slow1[2];
static unsigned int installed = 0;
static unsigned int save__window_overflow_rettseq[3];
int
install_winoverflow_hook (void (*func) (void))
{
if (installed)
{
return 0;
}
if (!installed)
{
/*
a7 50 00 00 rd %wim, %l3
ae 10 00 01 mov %g1, %l7
83 34 e0 01 srl %l3, 1, %g1
81 c4 40 00 jmp %l1
81 cc 80 00 rett %l2 */
save__window_overflow_rettseq[0] = __window_overflow_rettseq[0];
save__window_overflow_rettseq[1] = __window_overflow_rettseq[1];
save__window_overflow_rettseq[2] = __window_overflow_rettseq[2];
/*29 10 00 31 sethi %hi(0x4000c400), %l4
81 c5 22 48 jmp %l4 + 0x248
01 00 00 00 nop */
__window_overflow_rettseq[0] = ((((unsigned int) func) >> 10) & 0x3fffff) | 0x29000000; /* upper 22 */
__window_overflow_rettseq[1] = ((((unsigned int) func)) & 0x03ff) | 0x81c52000; /* lower 10 */
__window_overflow_rettseq[2] = 0x01000000; /* nop */
sparc_leon23_icache_flush ();
installed = 1;
}
return 0;
}
void
uninstall_winoverflow_hook ()
{
if (installed)
{
__window_overflow_rettseq[0] = save__window_overflow_rettseq[0];
__window_overflow_rettseq[1] = save__window_overflow_rettseq[1];
__window_overflow_rettseq[2] = save__window_overflow_rettseq[2];
sparc_leon23_icache_flush ();
installed = 0;
}
}