// ################################################################################################# // # << NEORV32: neorv32_cpu.h - CPU Core Functions HW Driver >> # // # ********************************************************************************************* # // # BSD 3-Clause License # // # # // # Copyright (c) 2021, Stephan Nolting. All rights reserved. # // # # // # Redistribution and use in source and binary forms, with or without modification, are # // # permitted provided that the following conditions are met: # // # # // # 1. Redistributions of source code must retain the above copyright notice, this list of # // # conditions and the following disclaimer. # // # # // # 2. Redistributions in binary form must reproduce the above copyright notice, this list of # // # conditions and the following disclaimer in the documentation and/or other materials # // # provided with the distribution. # // # # // # 3. Neither the name of the copyright holder nor the names of its contributors may be used to # // # endorse or promote products derived from this software without specific prior written # // # permission. # // # # // # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS # // # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF # // # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE # // # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, # // # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE # // # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED # // # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING # // # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED # // # OF THE POSSIBILITY OF SUCH DAMAGE. # // # ********************************************************************************************* # // # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting # // ################################################################################################# /**********************************************************************//** * @file neorv32_cpu.h * @author Stephan Nolting * @brief CPU Core Functions HW driver header file. **************************************************************************/ #ifndef neorv32_cpu_h #define neorv32_cpu_h // prototypes int neorv32_cpu_irq_enable(uint8_t irq_sel); int neorv32_cpu_irq_disable(uint8_t irq_sel); uint64_t neorv32_cpu_get_cycle(void); void neorv32_cpu_set_mcycle(uint64_t value); uint64_t neorv32_cpu_get_instret(void); void neorv32_cpu_set_minstret(uint64_t value); uint64_t neorv32_cpu_get_systime(void); void neorv32_cpu_delay_ms(uint32_t time_ms); void __attribute__((naked)) neorv32_cpu_goto_user_mode(void); uint32_t neorv32_cpu_pmp_get_num_regions(void); uint32_t neorv32_cpu_pmp_get_granularity(void); int neorv32_cpu_pmp_configure_region(uint32_t index, uint32_t base, uint32_t size, uint8_t config); uint32_t neorv32_cpu_hpm_get_counters(void); uint32_t neorv32_cpu_hpm_get_size(void); /**********************************************************************//** * Prototype for "after-main handler". This function is called if main() returns. * * @param[in] return_code Return value of main() function. * @return Return value is irrelevant (there is no one left to check for it...). **************************************************************************/ extern int __neorv32_crt0_after_main(int32_t return_code) __attribute__ ((weak)); /**********************************************************************//** * Store unsigned word to address space if atomic access reservation is still valid. * * @note An unaligned access address will raise an alignment exception. * * @param[in] addr Address (32-bit). * @param[in] wdata Data word (32-bit) to store. * @return Operation status (32-bit, zero if success). **************************************************************************/ inline uint32_t __attribute__ ((always_inline)) neorv32_cpu_store_conditional(uint32_t addr, uint32_t wdata) { #if defined __riscv_atomic || defined __riscv_a register uint32_t reg_addr = addr; register uint32_t reg_data = wdata; register uint32_t reg_status; asm volatile ("sc.w %[status], %[da], (%[ad])" : [status] "=r" (reg_status) : [da] "r" (reg_data), [ad] "r" (reg_addr)); return reg_status; #else return 1; // always failing #endif } /**********************************************************************//** * Conditional store unsigned word to address space. * * @note An unaligned access address will raise an alignment exception. * * @param[in] addr Address (32-bit). * @param[in] wdata Data word (32-bit) to store. **************************************************************************/ inline void __attribute__ ((always_inline)) neorv32_cpu_store_unsigned_word(uint32_t addr, uint32_t wdata) { register uint32_t reg_addr = addr; register uint32_t reg_data = wdata; asm volatile ("sw %[da], 0(%[ad])" : : [da] "r" (reg_data), [ad] "r" (reg_addr)); } /**********************************************************************//** * Store unsigned half-word to address space. * * @note An unaligned access address will raise an alignment exception. * * @param[in] addr Address (32-bit). * @param[in] wdata Data half-word (16-bit) to store. **************************************************************************/ inline void __attribute__ ((always_inline)) neorv32_cpu_store_unsigned_half(uint32_t addr, uint16_t wdata) { register uint32_t reg_addr = addr; register uint32_t reg_data = (uint32_t)wdata; asm volatile ("sh %[da], 0(%[ad])" : : [da] "r" (reg_data), [ad] "r" (reg_addr)); } /**********************************************************************//** * Store unsigned byte to address space. * * @param[in] addr Address (32-bit). * @param[in] wdata Data byte (8-bit) to store. **************************************************************************/ inline void __attribute__ ((always_inline)) neorv32_cpu_store_unsigned_byte(uint32_t addr, uint8_t wdata) { register uint32_t reg_addr = addr; register uint32_t reg_data = (uint32_t)wdata; asm volatile ("sb %[da], 0(%[ad])" : : [da] "r" (reg_data), [ad] "r" (reg_addr)); } /**********************************************************************//** * Load unsigned word from address space and make reservation for atomic access. * * @note An unaligned access address will raise an alignment exception. * * @param[in] addr Address (32-bit). * @return Read data word (32-bit). **************************************************************************/ inline uint32_t __attribute__ ((always_inline)) neorv32_cpu_load_reservate_word(uint32_t addr) { register uint32_t reg_addr = addr; register uint32_t reg_data; #if defined __riscv_atomic || defined __riscv_a asm volatile ("lr.w %[da], 0(%[ad])" : [da] "=r" (reg_data) : [ad] "r" (reg_addr)); #else asm volatile ("lw %[da], 0(%[ad])" : [da] "=r" (reg_data) : [ad] "r" (reg_addr)); #endif return (uint32_t)reg_data; } /**********************************************************************//** * Load unsigned word from address space. * * @note An unaligned access address will raise an alignment exception. * * @param[in] addr Address (32-bit). * @return Read data word (32-bit). **************************************************************************/ inline uint32_t __attribute__ ((always_inline)) neorv32_cpu_load_unsigned_word(uint32_t addr) { register uint32_t reg_addr = addr; register uint32_t reg_data; asm volatile ("lw %[da], 0(%[ad])" : [da] "=r" (reg_data) : [ad] "r" (reg_addr)); return (uint32_t)reg_data; } /**********************************************************************//** * Load unsigned half-word from address space. * * @note An unaligned access address will raise an alignment exception. * * @param[in] addr Address (32-bit). * @return Read data half-word (16-bit). **************************************************************************/ inline uint16_t __attribute__ ((always_inline)) neorv32_cpu_load_unsigned_half(uint32_t addr) { register uint32_t reg_addr = addr; register uint32_t reg_data; asm volatile ("lhu %[da], 0(%[ad])" : [da] "=r" (reg_data) : [ad] "r" (reg_addr)); return (uint16_t)reg_data; } /**********************************************************************//** * Load unsigned byte from address space. * * @param[in] addr Address (32-bit). * @return Read data byte (8-bit). **************************************************************************/ inline uint8_t __attribute__ ((always_inline)) neorv32_cpu_load_unsigned_byte(uint32_t addr) { register uint32_t reg_addr = addr; register uint32_t reg_data; asm volatile ("lbu %[da], 0(%[ad])" : [da] "=r" (reg_data) : [ad] "r" (reg_addr)); return (uint8_t)reg_data; } /**********************************************************************//** * Read data from CPU configuration and status register (CSR). * * @param[in] csr_id ID of CSR to read. See #NEORV32_CSR_enum. * @return Read data (uint32_t). **************************************************************************/ inline uint32_t __attribute__ ((always_inline)) neorv32_cpu_csr_read(const int csr_id) { register uint32_t csr_data; asm volatile ("csrr %[result], %[input_i]" : [result] "=r" (csr_data) : [input_i] "i" (csr_id)); return csr_data; } /**********************************************************************//** * Write data to CPU configuration and status register (CSR). * * @param[in] csr_id ID of CSR to write. See #NEORV32_CSR_enum. * @param[in] data Data to write (uint32_t). **************************************************************************/ inline void __attribute__ ((always_inline)) neorv32_cpu_csr_write(const int csr_id, uint32_t data) { register uint32_t csr_data = data; asm volatile ("csrw %[input_i], %[input_j]" : : [input_i] "i" (csr_id), [input_j] "r" (csr_data)); } /**********************************************************************//** * Put CPU into "sleep" mode. * * @note This function executes the WFI instruction. * The WFI (wait for interrupt) instruction will make the CPU stall until * an interrupt request is detected. Interrupts have to be globally enabled * and at least one external source must be enabled (like the MTI machine * timer interrupt) to allow the CPU to wake up again. If 'Zicsr' CPU extension is disabled, * this will permanently stall the CPU. **************************************************************************/ inline void __attribute__ ((always_inline)) neorv32_cpu_sleep(void) { asm volatile ("wfi"); } /**********************************************************************//** * Enable global CPU interrupts (via MIE flag in mstatus CSR). **************************************************************************/ inline void __attribute__ ((always_inline)) neorv32_cpu_eint(void) { asm volatile ("csrrsi zero, mstatus, %0" : : "i" (1 << CSR_MSTATUS_MIE)); } /**********************************************************************//** * Disable global CPU interrupts (via MIE flag in mstatus CSR). **************************************************************************/ inline void __attribute__ ((always_inline)) neorv32_cpu_dint(void) { asm volatile ("csrrci zero, mstatus, %0" : : "i" (1 << CSR_MSTATUS_MIE)); } /**********************************************************************//** * Trigger breakpoint exception (via EBREAK instruction). **************************************************************************/ inline void __attribute__ ((always_inline)) neorv32_cpu_breakpoint(void) { asm volatile ("ebreak"); } /**********************************************************************//** * Trigger "environment call" exception (via ECALL instruction). **************************************************************************/ inline void __attribute__ ((always_inline)) neorv32_cpu_env_call(void) { asm volatile ("ecall"); } #endif // neorv32_cpu_h