# Copyright (c) 2016 Jean-Paul Etienne # SPDX-License-Identifier: Apache-2.0 menu "RISCV Options" depends on RISCV config ARCH string default "riscv" config FLOAT_HARD bool "Hard-float calling convention" default y depends on FPU help This option enables the hard-float calling convention. config RISCV_GP bool "RISC-V global pointer relative addressing" default n help Use global pointer relative addressing for small globals declared anywhere in the executable. It can benefit performance and reduce the code size. Note: To support this feature, RISC-V SoC needs to initialize global pointer at program start or earlier than any instruction using GP relative addressing. config RISCV_ALWAYS_SWITCH_THROUGH_ECALL bool "Do not use mret outside a trap handler context" depends on MULTITHREADING depends on !RISCV_PMP help Use mret instruction only when in a trap handler. This is for RISC-V implementations that require every mret to be balanced with an ecall. This is not required by the RISC-V spec and most people should say n here to minimize context switching overhead. menu "RISCV Processor Options" config INCLUDE_RESET_VECTOR bool "Include Reset vector" help Include the reset vector stub, which initializes the stack and prepares for running C code. config RISCV_PRIVILEGED bool select ARCH_HAS_RAMFUNC_SUPPORT if XIP help Option selected by SoCs implementing the RISC-V privileged ISA. config RISCV_SOC_HAS_ISR_STACKING bool depends on !USERSPACE help Enable low-level SOC-specific hardware stacking / unstacking operations during ISR. This hidden option needs to be selected by SoC if this feature is supported. Some SOCs implement a mechanism for which, on interrupt handling, part of the context is automatically saved by the hardware on the stack according to a custom ESF format. The same part of the context is automatically restored by hardware on mret. Enabling this option requires that the SoC provides a soc_isr_stacking.h header which defines the following: - SOC_ISR_SW_STACKING: macro guarded by _ASMLANGUAGE called by the IRQ wrapper assembly code on ISR entry to save in the ESF the remaining part of the context not pushed already on the stack by the hardware. - SOC_ISR_SW_UNSTACKING: macro guarded by _ASMLANGUAGE called by the IRQ wrapper assembly code on ISR exit to restore the part of the context from the ESF that won't be restored by hardware on mret. - SOC_ISR_STACKING_ESF_DECLARE: structure declaration for the ESF guarded by !_ASMLANGUAGE. The ESF should be defined to account for the hardware stacked registers in the proper order as they are saved on the stack by the hardware, and the registers saved by the software macros. The structure must be called '__esf'. config RISCV_SOC_HAS_CUSTOM_IRQ_HANDLING bool help This allows the SoC to overwrite the irq handling. If enabled, the function __soc_handle_all_irqs has to be implemented. It shall service and clear all pending interrupts. config RISCV_SOC_HAS_CUSTOM_IRQ_LOCK_OPS bool help Hidden option to allow SoC to overwrite arch_irq_lock(), arch_irq_unlock() and arch_irq_unlocked() functions with platform-specific versions named z_soc_irq_lock(), z_soc_irq_unlock() and z_soc_irq_unlocked(). Enable this hidden option and specialize the z_soc_* functions when the RISC-V SoC needs to do something different and more than reading and writing the mstatus register to lock and unlock the IRQs. config RISCV_SOC_HAS_CUSTOM_SYS_IO bool help Hidden option to allow SoC to overwrite sys_read*(), sys_write*() functions with platform-specific versions named z_soc_sys_read*() and z_soc_sys_write*(). Enable this hidden option and specialize the z_soc_* functions when the RISC-V SoC needs to do something different and more than reading and writing the registers. config RISCV_SOC_CONTEXT_SAVE bool "SOC-based context saving in IRQ handlers" select RISCV_SOC_OFFSETS help Enable low-level SOC-specific context management, for SOCs with extra state that must be saved when entering an interrupt/exception, and restored on exit. If unsure, leave this at the default value. Enabling this option requires that the SoC provide a soc_context.h header which defines the following macros: - SOC_ESF_MEMBERS: structure component declarations to allocate space for. The last such declaration should not end in a semicolon, for portability. The generic RISC-V architecture code will allocate space for these members in a "struct soc_esf" type (typedefed to soc_esf_t), which will be available if arch.h is included. - SOC_ESF_INIT: structure contents initializer for struct soc_esf state. The last initialized member should not end in a comma. The generic architecture IRQ wrapper will also call \_\_soc_save_context and \_\_soc_restore_context routines at ISR entry and exit, respectively. These should typically be implemented in assembly. If they were C functions, they would have these signatures: ``void __soc_save_context(soc_esf_t *state);`` ``void __soc_restore_context(soc_esf_t *state);`` The calls obey standard calling conventions; i.e., the state pointer address is in a0, and ra contains the return address. config RISCV_SOC_OFFSETS bool "SOC-based offsets" help Enabling this option requires that the SoC provide a soc_offsets.h header which defines the following macros: - GEN_SOC_OFFSET_SYMS(): a macro which expands to GEN_OFFSET_SYM(soc_esf_t, soc_specific_member) calls to ensure offset macros for SOC_ESF_MEMBERS are defined in offsets.h. The last one should not end in a semicolon. See gen_offset.h for more details. config RISCV_HAS_PLIC bool depends on RISCV_PRIVILEGED help Does the SOC provide support for a Platform Level Interrupt Controller (PLIC). config RISCV_HAS_CLIC bool depends on RISCV_PRIVILEGED help Does the SOC provide support for a Core-Local Interrupt Controller (CLIC). config RISCV_SOC_EXCEPTION_FROM_IRQ bool help Option selected by SoCs that require a custom mechanism to check if an exception is the result of an interrupt or not. If selected, __soc_is_irq() needs to be implemented by the SoC. config RISCV_SOC_INTERRUPT_INIT bool "SOC-based interrupt initialization" help Enable SOC-based interrupt initialization (call soc_interrupt_init, within _IntLibInit when enabled) config RISCV_MCAUSE_EXCEPTION_MASK hex default 0x7FFFFFFFFFFFFFFF if 64BIT default 0x7FFFFFFF help Specify the bits to use for exception code in mcause register. config RISCV_GENERIC_TOOLCHAIN bool "Compile using generic riscv32 toolchain" default y help Compile using generic riscv32 toolchain. Allow SOCs that have custom extended riscv ISA to still compile with generic riscv32 toolchain. config GEN_ISR_TABLES default y config GEN_IRQ_VECTOR_TABLE default n config RISCV_RESERVED_IRQ_ISR_TABLES_OFFSET int default 0 depends on GEN_ISR_TABLES help On some RISCV platform the first interrupt vectors are primarly intended for inter-hart interrupt signaling and so retained for that purpose and not available. When this option is set, all the IRQ vectors are shifted by this offset value when installed into the software ISR table and the IRQ vector table. CONFIG_NUM_IRQS must be properly sized to take into account this offset. This is a hidden option which needs to be set per architecture and left alone. config NUM_IRQS int config RV_BOOT_HART int "Starting HART ID" default 0 help This option sets the starting HART ID for the SMP core. For RISC-V systems such as MPFS and FU540 this would be set to 1 to skip the E51 HART 0 as it is not usable in SMP configurations. config RISCV_HART_MASK int default -1 help Configures the mask for the HART ID. For RISC-V systems with HART ID starting from non-zero value, i.e. 128, 129, ..(0x80, 8x81, ..), this can be configured to 63 (0x7f) such that we can extract the bits that start from 0. config RISCV_PMP bool "RISC-V PMP Support" select THREAD_STACK_INFO select CPU_HAS_MPU select ARCH_HAS_USERSPACE select ARCH_HAS_STACK_PROTECTION select MPU select SRAM_REGION_PERMISSIONS select ARCH_MEM_DOMAIN_SYNCHRONOUS_API if USERSPACE select ARCH_MEM_DOMAIN_DATA if USERSPACE select THREAD_LOCAL_STORAGE if USERSPACE help MCU implements Physical Memory Protection. if RISCV_PMP config PMP_SLOTS int "Number of PMP slots" default 8 help This is the number of PMP entries implemented by the hardware. Typical values are 8 or 16. config PMP_NO_TOR bool help Set this if TOR (Top Of Range) mode is not supported. config PMP_NO_NA4 bool help Set this if NA4 (Naturally Aligned 4-byte) mode is not supported. config PMP_NO_NAPOT bool help Set this if NAPOT (Naturally Aligned Power Of Two) is not supported. config PMP_POWER_OF_TWO_ALIGNMENT bool "Enforce power-of-two alignment on PMP memory areas" if !PMP_NO_TOR default y if TEST_USERSPACE default y if (PMP_SLOTS = 8) default y if PMP_NO_TOR select MPU_REQUIRES_POWER_OF_TWO_ALIGNMENT select GEN_PRIV_STACKS help This option reduces the PMP slot usage but increases memory consumption. Useful when enabling userspace mode with many memory domains and/or few PMP slots available. config PMP_GRANULARITY int "The granularity of PMP address matching" default 8 if (PMP_NO_TOR && PMP_NO_NA4) default 4 help The granularity must be a power of 2 greater than or equal to 4 (ie 4, 8, 16, ...), but if neither TOR mode nor NA4 mode is supported, the minimum granularity is 8. endif #RISCV_PMP config PMP_STACK_GUARD def_bool y depends on MULTITHREADING depends on HW_STACK_PROTECTION config PMP_STACK_GUARD_MIN_SIZE int "Stack Guard area size" depends on PMP_STACK_GUARD default 1024 if 64BIT default 512 help The Hardware Stack Protection implements a guard area at the bottom of the stack using the PMP to catch stack overflows by marking that guard area not accessible. This is the size of the guard area. This should be large enough to catch any sudden jump in stack pointer decrement, plus some wiggle room to accommodate the eventual overflow exception stack usage. # Implement the null pointer detection using the Physical Memory Protection # (PMP) Unit. config NULL_POINTER_EXCEPTION_DETECTION_PMP bool "Use PMP for null pointer exception detection" depends on RISCV_PMP help Null pointer dereference detection implemented using PMP functionality. if NULL_POINTER_EXCEPTION_DETECTION_PMP config NULL_POINTER_EXCEPTION_REGION_SIZE hex "Inaccessible region to implement null pointer detection" default 0x10 help Use a PMP slot to make region (starting at address 0x0) inaccessible for detecting null pointer dereferencing (raising a CPU access fault). Minimum is 4 bytes. endif # NULL_POINTER_EXCEPTION_DETECTION_PMP endmenu config MAIN_STACK_SIZE default 4096 if 64BIT default 2048 if PMP_STACK_GUARD config TEST_EXTRA_STACK_SIZE default 1536 config CMSIS_THREAD_MAX_STACK_SIZE default 1024 if 64BIT config CMSIS_V2_THREAD_MAX_STACK_SIZE default 1024 if 64BIT config ARCH_IRQ_VECTOR_TABLE_ALIGN default 256 config RISCV_TRAP_HANDLER_ALIGNMENT int "Alignment of RISC-V trap handler in bytes" default 4 help This value configures the alignment of RISC-V trap handling code. The requirement for a particular alignment arises from the format of MTVEC register which is RISC-V platform-specific. The minimum alignment is 4 bytes according to the Spec. config GEN_IRQ_VECTOR_TABLE select RISCV_VECTORED_MODE if RISCV_PRIVILEGED config ARCH_HAS_SINGLE_THREAD_SUPPORT default y if !SMP rsource "Kconfig.isa" rsource "Kconfig.core" endmenu