zephyr/arch/riscv/include/offsets_short_arch.h

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arch: added support for the riscv32 architecture RISC-V is an open-source instruction set architecture. Added support for the 32bit version of RISC-V to Zephyr. 1) exceptions/interrupts/faults are handled at the architecture level via the __irq_wrapper handler. Context saving/restoring of registers can be handled at both architecture and SOC levels. If SOC-specific registers need to be saved, SOC level needs to provide __soc_save_context and __soc_restore_context functions that shall be accounted by the architecture level, when corresponding config variable RISCV_SOC_CONTEXT_SAVE is set. 2) As RISC-V architecture does not provide a clear ISA specification about interrupt handling, each RISC-V SOC handles it in its own way. Hence, at the architecture level, the __irq_wrapper handler expects the following functions to be provided by the SOC level: __soc_is_irq: to check if the exception is the result of an interrupt or not. __soc_handle_irq: handle pending IRQ at SOC level (ex: clear pending IRQ in SOC-specific IRQ register) 3) Thread/task scheduling, as well as IRQ offloading are handled via the RISC-V system call ("ecall"), which is also handled via the __irq_wrapper handler. The _Swap asm function just calls "ecall" to generate an exception. 4) As there is no conventional way of handling CPU power save in RISC-V, the default nano_cpu_idle and nano_cpu_atomic_idle functions just unlock interrupts and return to the caller, without issuing any CPU power saving instruction. Nonetheless, to allow SOC-level to implement proper CPU power save, nano_cpu_idle and nano_cpu_atomic_idle functions are defined as __weak at the architecture level. Change-Id: I980a161d0009f3f404ad22b226a6229fbb492389 Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
2017-01-11 07:24:30 +08:00
/*
* Copyright (c) 2016 Jean-Paul Etienne <fractalclone@gmail.com>
*
* SPDX-License-Identifier: Apache-2.0
arch: added support for the riscv32 architecture RISC-V is an open-source instruction set architecture. Added support for the 32bit version of RISC-V to Zephyr. 1) exceptions/interrupts/faults are handled at the architecture level via the __irq_wrapper handler. Context saving/restoring of registers can be handled at both architecture and SOC levels. If SOC-specific registers need to be saved, SOC level needs to provide __soc_save_context and __soc_restore_context functions that shall be accounted by the architecture level, when corresponding config variable RISCV_SOC_CONTEXT_SAVE is set. 2) As RISC-V architecture does not provide a clear ISA specification about interrupt handling, each RISC-V SOC handles it in its own way. Hence, at the architecture level, the __irq_wrapper handler expects the following functions to be provided by the SOC level: __soc_is_irq: to check if the exception is the result of an interrupt or not. __soc_handle_irq: handle pending IRQ at SOC level (ex: clear pending IRQ in SOC-specific IRQ register) 3) Thread/task scheduling, as well as IRQ offloading are handled via the RISC-V system call ("ecall"), which is also handled via the __irq_wrapper handler. The _Swap asm function just calls "ecall" to generate an exception. 4) As there is no conventional way of handling CPU power save in RISC-V, the default nano_cpu_idle and nano_cpu_atomic_idle functions just unlock interrupts and return to the caller, without issuing any CPU power saving instruction. Nonetheless, to allow SOC-level to implement proper CPU power save, nano_cpu_idle and nano_cpu_atomic_idle functions are defined as __weak at the architecture level. Change-Id: I980a161d0009f3f404ad22b226a6229fbb492389 Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
2017-01-11 07:24:30 +08:00
*/
#ifndef ZEPHYR_ARCH_RISCV_INCLUDE_OFFSETS_SHORT_ARCH_H_
#define ZEPHYR_ARCH_RISCV_INCLUDE_OFFSETS_SHORT_ARCH_H_
arch: added support for the riscv32 architecture RISC-V is an open-source instruction set architecture. Added support for the 32bit version of RISC-V to Zephyr. 1) exceptions/interrupts/faults are handled at the architecture level via the __irq_wrapper handler. Context saving/restoring of registers can be handled at both architecture and SOC levels. If SOC-specific registers need to be saved, SOC level needs to provide __soc_save_context and __soc_restore_context functions that shall be accounted by the architecture level, when corresponding config variable RISCV_SOC_CONTEXT_SAVE is set. 2) As RISC-V architecture does not provide a clear ISA specification about interrupt handling, each RISC-V SOC handles it in its own way. Hence, at the architecture level, the __irq_wrapper handler expects the following functions to be provided by the SOC level: __soc_is_irq: to check if the exception is the result of an interrupt or not. __soc_handle_irq: handle pending IRQ at SOC level (ex: clear pending IRQ in SOC-specific IRQ register) 3) Thread/task scheduling, as well as IRQ offloading are handled via the RISC-V system call ("ecall"), which is also handled via the __irq_wrapper handler. The _Swap asm function just calls "ecall" to generate an exception. 4) As there is no conventional way of handling CPU power save in RISC-V, the default nano_cpu_idle and nano_cpu_atomic_idle functions just unlock interrupts and return to the caller, without issuing any CPU power saving instruction. Nonetheless, to allow SOC-level to implement proper CPU power save, nano_cpu_idle and nano_cpu_atomic_idle functions are defined as __weak at the architecture level. Change-Id: I980a161d0009f3f404ad22b226a6229fbb492389 Signed-off-by: Jean-Paul Etienne <fractalclone@gmail.com>
2017-01-11 07:24:30 +08:00
#include <offsets.h>
/* kernel */
/* nothing for now */
/* end - kernel */
/* threads */
#define _thread_offset_to_sp \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_sp_OFFSET)
#define _thread_offset_to_s0 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s0_OFFSET)
#define _thread_offset_to_s1 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s1_OFFSET)
#define _thread_offset_to_s2 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s2_OFFSET)
#define _thread_offset_to_s3 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s3_OFFSET)
#define _thread_offset_to_s4 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s4_OFFSET)
#define _thread_offset_to_s5 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s5_OFFSET)
#define _thread_offset_to_s6 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s6_OFFSET)
#define _thread_offset_to_s7 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s7_OFFSET)
#define _thread_offset_to_s8 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s8_OFFSET)
#define _thread_offset_to_s9 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s9_OFFSET)
#define _thread_offset_to_s10 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s10_OFFSET)
#define _thread_offset_to_s11 \
(___thread_t_callee_saved_OFFSET + ___callee_saved_t_s11_OFFSET)
#define _thread_offset_to_swap_return_value \
(___thread_t_arch_OFFSET + ___thread_arch_t_swap_return_value_OFFSET)
/* end - threads */
#endif /* ZEPHYR_ARCH_RISCV_INCLUDE_OFFSETS_SHORT_ARCH_H_ */