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zephyr/arch/riscv32/core/swap.S

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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>
*
license: Replace Apache boilerplate with SPDX tag Replace the existing Apache 2.0 boilerplate header with an SPDX tag throughout the zephyr code tree. This patch was generated via a script run over the master branch. Also updated doc/porting/application.rst that had a dependency on line numbers in a literal include. Manually updated subsys/logging/sys_log.c that had a malformed header in the original file. Also cleanup several cases that already had a SPDX tag and we either got a duplicate or missed updating. Jira: ZEP-1457 Change-Id: I6131a1d4ee0e58f5b938300c2d2fc77d2e69572c Signed-off-by: David B. Kinder <david.b.kinder@intel.com> Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2017-01-19 09:01:01 +08:00
* 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
*/
#include <irq.h>
#include <kernel_structs.h>
#include <offsets_short.h>
/* exports */
kernel: tickless: Rename _Swap to allow creation of macro Future tickless kernel patches would be inserting some code before call to Swap. To enable this it will create a mcro named as the current _Swap which would call first the tickless kernel code and then call the real __swap() Jira: ZEP-339 Change-Id: Id778bfcee4f88982c958fcf22d7f04deb4bd572f Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
2017-04-07 06:30:27 +08:00
GTEXT(__swap)
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
GTEXT(_thread_entry_wrapper)
/* Use ABI name of registers for the sake of simplicity */
/*
kernel: tickless: Rename _Swap to allow creation of macro Future tickless kernel patches would be inserting some code before call to Swap. To enable this it will create a mcro named as the current _Swap which would call first the tickless kernel code and then call the real __swap() Jira: ZEP-339 Change-Id: Id778bfcee4f88982c958fcf22d7f04deb4bd572f Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
2017-04-07 06:30:27 +08:00
* unsigned int __swap(unsigned int key)
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
*
* Always called with interrupts locked
* key is stored in a0 register
*/
kernel: tickless: Rename _Swap to allow creation of macro Future tickless kernel patches would be inserting some code before call to Swap. To enable this it will create a mcro named as the current _Swap which would call first the tickless kernel code and then call the real __swap() Jira: ZEP-339 Change-Id: Id778bfcee4f88982c958fcf22d7f04deb4bd572f Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
2017-04-07 06:30:27 +08:00
SECTION_FUNC(exception.other, __swap)
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
/* Make a system call to perform context switch */
tests: benchmarks: timing_info: Enable benchmarks for riscv32. This patch provides support needed to get timing related information from riscv32 based SOC. Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
2018-07-23 18:24:22 +08:00
#ifdef CONFIG_EXECUTION_BENCHMARKING
addi sp, sp, -__NANO_ESF_SIZEOF
sw ra, __NANO_ESF_ra_OFFSET(sp)
sw gp, __NANO_ESF_gp_OFFSET(sp)
sw tp, __NANO_ESF_tp_OFFSET(sp)
sw t0, __NANO_ESF_t0_OFFSET(sp)
sw t1, __NANO_ESF_t1_OFFSET(sp)
sw t2, __NANO_ESF_t2_OFFSET(sp)
sw t3, __NANO_ESF_t3_OFFSET(sp)
sw t4, __NANO_ESF_t4_OFFSET(sp)
sw t5, __NANO_ESF_t5_OFFSET(sp)
sw t6, __NANO_ESF_t6_OFFSET(sp)
sw a0, __NANO_ESF_a0_OFFSET(sp)
sw a1, __NANO_ESF_a1_OFFSET(sp)
sw a2, __NANO_ESF_a2_OFFSET(sp)
sw a3, __NANO_ESF_a3_OFFSET(sp)
sw a4, __NANO_ESF_a4_OFFSET(sp)
sw a5, __NANO_ESF_a5_OFFSET(sp)
sw a6, __NANO_ESF_a6_OFFSET(sp)
sw a7, __NANO_ESF_a7_OFFSET(sp)
call read_timer_start_of_swap
lw ra, __NANO_ESF_ra_OFFSET(sp)
lw gp, __NANO_ESF_gp_OFFSET(sp)
lw tp, __NANO_ESF_tp_OFFSET(sp)
lw t0, __NANO_ESF_t0_OFFSET(sp)
lw t1, __NANO_ESF_t1_OFFSET(sp)
lw t2, __NANO_ESF_t2_OFFSET(sp)
lw t3, __NANO_ESF_t3_OFFSET(sp)
lw t4, __NANO_ESF_t4_OFFSET(sp)
lw t5, __NANO_ESF_t5_OFFSET(sp)
lw t6, __NANO_ESF_t6_OFFSET(sp)
lw a0, __NANO_ESF_a0_OFFSET(sp)
lw a1, __NANO_ESF_a1_OFFSET(sp)
lw a2, __NANO_ESF_a2_OFFSET(sp)
lw a3, __NANO_ESF_a3_OFFSET(sp)
lw a4, __NANO_ESF_a4_OFFSET(sp)
lw a5, __NANO_ESF_a5_OFFSET(sp)
lw a6, __NANO_ESF_a6_OFFSET(sp)
lw a7, __NANO_ESF_a7_OFFSET(sp)
/* Release stack space */
addi sp, sp, __NANO_ESF_SIZEOF
#endif
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
ecall
/*
* when thread is rescheduled, unlock irq and return.
* Restored register a0 contains IRQ lock state of thread.
*
* Prior to unlocking irq, load return value of
kernel: tickless: Rename _Swap to allow creation of macro Future tickless kernel patches would be inserting some code before call to Swap. To enable this it will create a mcro named as the current _Swap which would call first the tickless kernel code and then call the real __swap() Jira: ZEP-339 Change-Id: Id778bfcee4f88982c958fcf22d7f04deb4bd572f Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
2017-04-07 06:30:27 +08:00
* __swap to temp register t2 (from
* _thread_offset_to_swap_return_value). Normally, it should be -EAGAIN,
* unless someone has previously called _set_thread_return_value(..).
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
*/
la t0, _kernel
/* Get pointer to _kernel.current */
lw t1, _kernel_offset_to_current(t0)
kernel: tickless: Rename _Swap to allow creation of macro Future tickless kernel patches would be inserting some code before call to Swap. To enable this it will create a mcro named as the current _Swap which would call first the tickless kernel code and then call the real __swap() Jira: ZEP-339 Change-Id: Id778bfcee4f88982c958fcf22d7f04deb4bd572f Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
2017-04-07 06:30:27 +08:00
/* Load return value of __swap function in temp register t2 */
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
lw t2, _thread_offset_to_swap_return_value(t1)
/*
* Unlock irq, following IRQ lock state in a0 register.
* Use atomic instruction csrrs to do so.
*/
andi a0, a0, SOC_MSTATUS_IEN
csrrs t0, mstatus, a0
/* Set value of return register a0 to value of register t2 */
addi a0, t2, 0
/* Return */
jalr x0, ra
/*
zephyr: use k_thread_entry_t everywhere In various places, a private _thread_entry_t, or the full prototype were being used. Be consistent and use the same typedef everywhere. Signen-off-by: Andrew Boie <andrew.p.boie@intel.com>
2017-09-12 00:30:04 +08:00
* void _thread_entry_wrapper(k_thread_entry_t, void *, void *, void *)
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
*/
SECTION_FUNC(TEXT, _thread_entry_wrapper)
/*
* _thread_entry_wrapper is called for every new thread upon the return
kernel: tickless: Rename _Swap to allow creation of macro Future tickless kernel patches would be inserting some code before call to Swap. To enable this it will create a mcro named as the current _Swap which would call first the tickless kernel code and then call the real __swap() Jira: ZEP-339 Change-Id: Id778bfcee4f88982c958fcf22d7f04deb4bd572f Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
2017-04-07 06:30:27 +08:00
* of __swap or ISR. Its address, as well as its input function
* arguments thread_entry_t, void *, void *, void * are restored from
* the thread stack (initialized via function _thread).
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
* In this case, thread_entry_t, * void *, void * and void * are stored
* in registers a0, a1, a2 and a3. These registers are used as arguments
* to function _thread_entry. Hence, just call _thread_entry with
* return address set to 0 to indicate a non-returning function call.
*/
jal x0, _thread_entry