/* * Copyright (c) 2021-2024, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #ifndef EL2_COMMON_MACROS_S #define EL2_COMMON_MACROS_S #include #include #include #include #include /* * Helper macro to initialise system registers at EL2. */ .macro el2_arch_init_common /* --------------------------------------------------------------------- * SCTLR_EL2 has already been initialised - read current value before * modifying. * * SCTLR_EL2.I: Enable the instruction cache. * * SCTLR_EL2.SA: Enable Stack Alignment check. A SP alignment fault * exception is generated if a load or store instruction executed at * EL2 uses the SP as the base address and the SP is not aligned to a * 16-byte boundary. * * SCTLR_EL2.A: Enable Alignment fault checking. All instructions that * load or store one or more registers have an alignment check that the * address being accessed is aligned to the size of the data element(s) * being accessed. * --------------------------------------------------------------------- */ mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT) mrs x0, sctlr_el2 orr x0, x0, x1 msr sctlr_el2, x0 isb /* --------------------------------------------------------------------- * Initialise HCR_EL2, setting all fields rather than relying on HW. * All fields are architecturally UNKNOWN on reset. The following fields * do not change during the TF lifetime. The remaining fields are set to * zero here but are updated ahead of transitioning to a lower EL in the * function cm_init_context_common(). * * HCR_EL2.TWE: Set to zero so that execution of WFE instructions at * EL2, EL1 and EL0 are not trapped to EL2. * * HCR_EL2.TWI: Set to zero so that execution of WFI instructions at * EL2, EL1 and EL0 are not trapped to EL2. * * HCR_EL2.HCD: Set to zero to enable HVC calls at EL1 and above, * from both Security states and both Execution states. * * HCR_EL2.TEA: Set to one to route External Aborts and SError * Interrupts to EL2 when executing at any EL. * * HCR_EL2.{API,APK}: For Armv8.3 pointer authentication feature, * disable traps to EL2 when accessing key registers or using * pointer authentication instructions from lower ELs. * --------------------------------------------------------------------- */ mov_imm x0, ((HCR_RESET_VAL | HCR_TEA_BIT) \ & ~(HCR_TWE_BIT | HCR_TWI_BIT | HCR_HCD_BIT)) #if CTX_INCLUDE_PAUTH_REGS /* * If the pointer authentication registers are saved during world * switches, enable pointer authentication everywhere, as it is safe to * do so. */ orr x0, x0, #(HCR_API_BIT | HCR_APK_BIT) #endif /* CTX_INCLUDE_PAUTH_REGS */ msr hcr_el2, x0 /* --------------------------------------------------------------------- * Initialise MDCR_EL2, setting all fields rather than relying on * hw. Some fields are architecturally UNKNOWN on reset. * * MDCR_EL2.TDOSA: Set to zero so that EL2 and EL2 System register * access to the powerdown debug registers do not trap to EL2. * * MDCR_EL2.TDA: Set to zero to allow EL0, EL1 and EL2 access to the * debug registers, other than those registers that are controlled by * MDCR_EL2.TDOSA. * * MDCR_EL2.TPM: Set to zero so that EL0, EL1, and EL2 System * register accesses to all Performance Monitors registers do not trap * to EL2. * * MDCR_EL2.HPMD: Set to zero so that event counting by the program- * mable counters PMEVCNTR_EL0 is prohibited in Secure state. If * ARMv8.2 Debug is not implemented this bit does not have any effect * on the counters unless there is support for the implementation * defined authentication interface * ExternalSecureNoninvasiveDebugEnabled(). * --------------------------------------------------------------------- */ mov_imm x0, ((MDCR_EL2_RESET_VAL | \ MDCR_SPD32(MDCR_SPD32_DISABLE)) \ & ~(MDCR_EL2_HPMD_BIT | MDCR_TDOSA_BIT | \ MDCR_TDA_BIT | MDCR_TPM_BIT)) msr mdcr_el2, x0 /* --------------------------------------------------------------------- * Initialise PMCR_EL0 setting all fields rather than relying * on hw. Some fields are architecturally UNKNOWN on reset. * * PMCR_EL0.DP: Set to one so that the cycle counter, * PMCCNTR_EL0 does not count when event counting is prohibited. * * PMCR_EL0.X: Set to zero to disable export of events. * * PMCR_EL0.D: Set to zero so that, when enabled, PMCCNTR_EL0 * counts on every clock cycle. * --------------------------------------------------------------------- */ mov_imm x0, ((PMCR_EL0_RESET_VAL | PMCR_EL0_DP_BIT) & \ ~(PMCR_EL0_X_BIT | PMCR_EL0_D_BIT)) msr pmcr_el0, x0 /* --------------------------------------------------------------------- * Enable External Aborts and SError Interrupts now that the exception * vectors have been setup. * --------------------------------------------------------------------- */ msr daifclr, #DAIF_ABT_BIT /* --------------------------------------------------------------------- * Initialise CPTR_EL2, setting all fields rather than relying on hw. * All fields are architecturally UNKNOWN on reset. * * CPTR_EL2.TCPAC: Set to zero so that any accesses to CPACR_EL1 do * not trap to EL2. * * CPTR_EL2.TTA: Set to zero so that System register accesses to the * trace registers do not trap to EL2. * * CPTR_EL2.TFP: Set to zero so that accesses to the V- or Z- registers * by Advanced SIMD, floating-point or SVE instructions (if implemented) * do not trap to EL2. */ mov_imm x0, (CPTR_EL2_RESET_VAL & ~(TCPAC_BIT | TTA_BIT | TFP_BIT)) msr cptr_el2, x0 /* * If Data Independent Timing (DIT) functionality is implemented, * always enable DIT in EL2 */ mrs x0, id_aa64pfr0_el1 ubfx x0, x0, #ID_AA64PFR0_DIT_SHIFT, #ID_AA64PFR0_DIT_LENGTH cmp x0, #DIT_IMPLEMENTED bne 1f mov x0, #DIT_BIT msr DIT, x0 1: .endm /* ----------------------------------------------------------------------------- * This is the super set of actions that need to be performed during a cold boot * or a warm boot in EL2. This code is shared by BL1 and BL31. * * This macro will always perform reset handling, architectural initialisations * and stack setup. The rest of the actions are optional because they might not * be needed, depending on the context in which this macro is called. This is * why this macro is parameterised ; each parameter allows to enable/disable * some actions. * * _init_sctlr: * Whether the macro needs to initialise SCTLR_EL2, including configuring * the endianness of data accesses. * * _warm_boot_mailbox: * Whether the macro needs to detect the type of boot (cold/warm). The * detection is based on the platform entrypoint address : if it is zero * then it is a cold boot, otherwise it is a warm boot. In the latter case, * this macro jumps on the platform entrypoint address. * * _secondary_cold_boot: * Whether the macro needs to identify the CPU that is calling it: primary * CPU or secondary CPU. The primary CPU will be allowed to carry on with * the platform initialisations, while the secondaries will be put in a * platform-specific state in the meantime. * * If the caller knows this macro will only be called by the primary CPU * then this parameter can be defined to 0 to skip this step. * * _init_memory: * Whether the macro needs to initialise the memory. * * _init_c_runtime: * Whether the macro needs to initialise the C runtime environment. * * _exception_vectors: * Address of the exception vectors to program in the VBAR_EL2 register. * * _pie_fixup_size: * Size of memory region to fixup Global Descriptor Table (GDT). * * A non-zero value is expected when firmware needs GDT to be fixed-up. * * ----------------------------------------------------------------------------- */ .macro el2_entrypoint_common \ _init_sctlr, _warm_boot_mailbox, _secondary_cold_boot, \ _init_memory, _init_c_runtime, _exception_vectors, \ _pie_fixup_size .if \_init_sctlr /* ------------------------------------------------------------- * This is the initialisation of SCTLR_EL2 and so must ensure * that all fields are explicitly set rather than relying on hw. * Some fields reset to an IMPLEMENTATION DEFINED value and * others are architecturally UNKNOWN on reset. * * SCTLR.EE: Set the CPU endianness before doing anything that * might involve memory reads or writes. Set to zero to select * Little Endian. * * SCTLR_EL2.WXN: For the EL2 translation regime, this field can * force all memory regions that are writeable to be treated as * XN (Execute-never). Set to zero so that this control has no * effect on memory access permissions. * * SCTLR_EL2.SA: Set to zero to disable Stack Alignment check. * * SCTLR_EL2.A: Set to zero to disable Alignment fault checking. * * SCTLR.DSSBS: Set to zero to disable speculation store bypass * safe behaviour upon exception entry to EL2. * ------------------------------------------------------------- */ mov_imm x0, (SCTLR_RESET_VAL & ~(SCTLR_EE_BIT | SCTLR_WXN_BIT \ | SCTLR_SA_BIT | SCTLR_A_BIT | SCTLR_DSSBS_BIT)) msr sctlr_el2, x0 isb .endif /* _init_sctlr */ .if \_warm_boot_mailbox /* ------------------------------------------------------------- * This code will be executed for both warm and cold resets. * Now is the time to distinguish between the two. * Query the platform entrypoint address and if it is not zero * then it means it is a warm boot so jump to this address. * ------------------------------------------------------------- */ bl plat_get_my_entrypoint cbz x0, do_cold_boot br x0 do_cold_boot: .endif /* _warm_boot_mailbox */ .if \_pie_fixup_size #if ENABLE_PIE /* * ------------------------------------------------------------ * If PIE is enabled fixup the Global descriptor Table only * once during primary core cold boot path. * * Compile time base address, required for fixup, is calculated * using "pie_fixup" label present within first page. * ------------------------------------------------------------ */ pie_fixup: ldr x0, =pie_fixup and x0, x0, #~(PAGE_SIZE_MASK) mov_imm x1, \_pie_fixup_size add x1, x1, x0 bl fixup_gdt_reloc #endif /* ENABLE_PIE */ .endif /* _pie_fixup_size */ /* --------------------------------------------------------------------- * Set the exception vectors. * --------------------------------------------------------------------- */ adr x0, \_exception_vectors msr vbar_el2, x0 isb /* --------------------------------------------------------------------- * It is a cold boot. * Perform any processor specific actions upon reset e.g. cache, TLB * invalidations etc. * --------------------------------------------------------------------- */ bl reset_handler el2_arch_init_common .if \_secondary_cold_boot /* ------------------------------------------------------------- * Check if this is a primary or secondary CPU cold boot. * The primary CPU will set up the platform while the * secondaries are placed in a platform-specific state until the * primary CPU performs the necessary actions to bring them out * of that state and allows entry into the OS. * ------------------------------------------------------------- */ bl plat_is_my_cpu_primary cbnz w0, do_primary_cold_boot /* This is a cold boot on a secondary CPU */ bl plat_secondary_cold_boot_setup /* plat_secondary_cold_boot_setup() is not supposed to return */ bl el2_panic do_primary_cold_boot: .endif /* _secondary_cold_boot */ /* --------------------------------------------------------------------- * Initialize memory now. Secondary CPU initialization won't get to this * point. * --------------------------------------------------------------------- */ .if \_init_memory bl platform_mem_init .endif /* _init_memory */ /* --------------------------------------------------------------------- * Init C runtime environment: * - Zero-initialise the NOBITS sections. There are 2 of them: * - the .bss section; * - the coherent memory section (if any). * - Relocate the data section from ROM to RAM, if required. * --------------------------------------------------------------------- */ .if \_init_c_runtime adrp x0, __BSS_START__ add x0, x0, :lo12:__BSS_START__ adrp x1, __BSS_END__ add x1, x1, :lo12:__BSS_END__ sub x1, x1, x0 bl zeromem #if defined(IMAGE_BL1) || (defined(IMAGE_BL2) && \ RESET_TO_BL2 && BL2_IN_XIP_MEM) adrp x0, __DATA_RAM_START__ add x0, x0, :lo12:__DATA_RAM_START__ adrp x1, __DATA_ROM_START__ add x1, x1, :lo12:__DATA_ROM_START__ adrp x2, __DATA_RAM_END__ add x2, x2, :lo12:__DATA_RAM_END__ sub x2, x2, x0 bl memcpy16 #endif .endif /* _init_c_runtime */ /* --------------------------------------------------------------------- * Use SP_EL0 for the C runtime stack. * --------------------------------------------------------------------- */ msr spsel, #0 /* --------------------------------------------------------------------- * Allocate a stack whose memory will be marked as Normal-IS-WBWA when * the MMU is enabled. There is no risk of reading stale stack memory * after enabling the MMU as only the primary CPU is running at the * moment. * --------------------------------------------------------------------- */ bl plat_set_my_stack #if STACK_PROTECTOR_ENABLED .if \_init_c_runtime bl update_stack_protector_canary .endif /* _init_c_runtime */ #endif .endm .macro apply_at_speculative_wa #if ERRATA_SPECULATIVE_AT /* * This function expects x30 has been saved. * Also, save x29 which will be used in the called function. */ str x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29] bl save_and_update_ptw_el1_sys_regs ldr x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29] #endif .endm .macro restore_ptw_el1_sys_regs #if ERRATA_SPECULATIVE_AT /* ----------------------------------------------------------- * In case of ERRATA_SPECULATIVE_AT, must follow below order * to ensure that page table walk is not enabled until * restoration of all EL1 system registers. TCR_EL1 register * should be updated at the end which restores previous page * table walk setting of stage1 i.e.(TCR_EL1.EPDx) bits. ISB * ensures that CPU does below steps in order. * * 1. Ensure all other system registers are written before * updating SCTLR_EL1 using ISB. * 2. Restore SCTLR_EL1 register. * 3. Ensure SCTLR_EL1 written successfully using ISB. * 4. Restore TCR_EL1 register. * ----------------------------------------------------------- */ isb ldp x28, x29, [sp, #CTX_EL1_SYSREGS_OFFSET + CTX_SCTLR_EL1] msr sctlr_el1, x28 isb msr tcr_el1, x29 #endif .endm #endif /* EL2_COMMON_MACROS_S */