qemu-patch-raspberry4/linux-user/openrisc/target_cpu.h
Stafford Horne d89e71e873 target/openrisc: implement shadow registers
Shadow registers are part of the openrisc spec along with sr[cid], as
part of the fast context switching feature.  When exceptions occur,
instead of having to save registers to the stack if enabled the CID will
increment and a new set of registers will be available.

This patch only implements shadow registers which can be used as extra
scratch registers via the mfspr and mtspr if required.  This is
implemented in a way where it would be easy to add on the fast context
switching, currently cid is hardcoded to 0.

This is need for openrisc linux smp kernels to boot correctly.

Signed-off-by: Stafford Horne <shorne@gmail.com>
2017-05-04 09:39:01 +09:00

37 lines
1.1 KiB
C

/*
* OpenRISC specific CPU ABI and functions for linux-user
*
* Copyright (c) 2011-2012 Jia Liu <proljc@gmail.com>
*
* This 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 of the License, or (at your option) any later version.
*
* This 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 this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef OPENRISC_TARGET_CPU_H
#define OPENRISC_TARGET_CPU_H
static inline void cpu_clone_regs(CPUOpenRISCState *env, target_ulong newsp)
{
if (newsp) {
cpu_set_gpr(env, 1, newsp);
}
cpu_set_gpr(env, 11, 0);
}
static inline void cpu_set_tls(CPUOpenRISCState *env, target_ulong newtls)
{
cpu_set_gpr(env, 10, newtls);
}
#endif