Atmosphere/thermosphere/src/regs.h

73 lines
2.1 KiB
C

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __REGS_H__
#define __REGS_H__
/**
* Access to system registers.
*/
#define WRITE_SYSREG(sysreg, val, type) \
asm volatile ("msr "#sysreg", %0\n" : : "r"((type)(val)))
#define READ_SYSREG(sysreg, val, type) \
asm volatile ("mrs %0, "#sysreg"\n" : "=r"((type)(val)))
#define READ_SYSREG_32(sysreg, val) READ_SYSREG(sysreg, val, uint32_t)
#define WRITE_SYSREG_32(sysreg, val) WRITE_SYSREG(sysreg, val, uint32_t)
#define READ_SYSREG_64(sysreg, val) READ_SYSREG(sysreg, val, uint64_t)
#define WRITE_SYSREG_64(sysreg, val) WRITE_SYSREG(sysreg, val, uint64_t)
/**
* Returns the system's current Execution Level (EL).
*/
inline static uint32_t get_current_el(void) {
uint32_t val;
// Read the CurrentEl register, and extract the bits that tell us our EL.
READ_SYSREG_32(CurrentEl, val);
return val >> 2;
}
/**
* Sets the base address of the EL2 exception table.
*/
inline static void set_vbar_el2(void * address) {
WRITE_SYSREG_64(vbar_el2, (uint64_t)address);
}
/**
* Sets the address to 'return to' when leaving EL2.
*/
inline static void set_elr_el2(void * address) {
WRITE_SYSREG_64(elr_el2, (uint64_t)address);
}
/**
* Returns the MMU status bit from the SCTLR register.
*/
inline static uint32_t get_el2_mmu_status(void) {
uint32_t val;
// Read the CurrentEl register, and extract the bits that tell us our EL.
READ_SYSREG_32(sctlr_el2, val);
return val & 1;
}
#endif