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RIOT/cpu/riscv_common/riscv_init.c
2023-06-28 11:55:34 +02:00

62 lines
1.4 KiB
C

/*
* Copyright (C) 2020, Koen Zandberg <koen@bergzand.net>
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup cpu_riscv_common
* @{
*
* @file cpu.c
* @brief Common CPU initialization for RISC-V rv32i architecture
*
* @author Koen Zandberg <koen@bergzand.net>
* @}
*/
#include "cpu.h"
#include "cpu_conf_common.h"
#include "periph_cpu_common.h"
#ifdef MODULE_PMP_NOEXEC_RAM
#include "pmp.h"
#endif
#ifdef MODULE_PUF_SRAM
#include "puf_sram.h"
extern unsigned _sheap;
void riscv_puf_sram_init(void)
{
puf_sram_init((uint8_t *)&_sheap, SEED_RAM_LEN);
}
#endif /* MODULE_PUF_SRAM */
void riscv_fpu_init(void)
{
/* Enable FPU if present */
if (read_csr(misa) & (1 << ('F' - 'A'))) {
write_csr(mstatus, MSTATUS_FS); /* allow FPU instructions without trapping */
write_csr(fcsr, 0); /* initialize rounding mode, undefined at reset */
}
}
void riscv_init(void)
{
riscv_fpu_init();
riscv_irq_init();
#ifdef MODULE_PMP_NOEXEC_RAM
/* This marks the (main) RAM region as non
* executable. Using PMP entry 0.
*/
write_pmpaddr(0, make_napot(CPU_RAM_BASE, CPU_RAM_SIZE));
/* Lock & select NAPOT, only allow write and read */
set_pmpcfg(0, PMP_L | PMP_NAPOT | PMP_W | PMP_R);
#endif
}