| # x86 general configuration options |
| |
| # Copyright (c) 2014-2015 Wind River Systems, Inc. |
| # SPDX-License-Identifier: Apache-2.0 |
| |
| menu "X86 Architecture Options" |
| depends on X86 |
| |
| config ARCH |
| default "x86" |
| |
| # |
| # CPU Families - the SoC configuration should select the right one. |
| # |
| |
| config CPU_ATOM |
| bool |
| select CPU_HAS_FPU |
| select ARCH_HAS_STACK_PROTECTION if X86_MMU |
| select ARCH_HAS_USERSPACE if X86_MMU |
| select X86_CPU_HAS_MMX |
| select X86_CPU_HAS_SSE |
| select X86_CPU_HAS_SSE2 |
| select X86_CPU_HAS_SSE3 |
| select CPU_HAS_DCACHE |
| help |
| This option signifies the use of a CPU from the Atom family. |
| |
| config CPU_APOLLO_LAKE |
| bool |
| select CPU_HAS_FPU |
| select ARCH_HAS_STACK_PROTECTION if X86_MMU |
| select ARCH_HAS_USERSPACE if X86_MMU |
| select X86_MMU |
| select X86_CPU_HAS_MMX |
| select X86_CPU_HAS_SSE |
| select X86_CPU_HAS_SSE2 |
| select X86_CPU_HAS_SSE3 |
| select X86_CPU_HAS_SSSE3 |
| select X86_CPU_HAS_SSE41 |
| select X86_CPU_HAS_SSE42 |
| select CPU_HAS_DCACHE |
| help |
| This option signifies the use of a CPU from the Apollo Lake family. |
| |
| config CPU_LAKEMONT |
| bool |
| select CPU_HAS_FPU |
| select ARCH_HAS_STACK_PROTECTION if X86_MMU |
| select ARCH_HAS_USERSPACE if X86_MMU |
| select X86_CPU_HAS_MMX |
| select X86_CPU_HAS_SSE |
| select X86_CPU_HAS_SSE2 |
| select X86_CPU_HAS_SSE3 |
| select X86_CPU_HAS_SSSE3 |
| select CPU_HAS_DCACHE |
| help |
| This option signifies the use of a CPU from the Lakemont family. |
| |
| # |
| # Configuration common to both IA32 and Intel64 sub-architectures. |
| # |
| |
| config X86_64 |
| bool "Run in 64-bit mode" |
| select 64BIT |
| select USE_SWITCH |
| select USE_SWITCH_SUPPORTED |
| select SCHED_IPI_SUPPORTED |
| select X86_MMU |
| select X86_CPU_HAS_MMX |
| select X86_CPU_HAS_SSE |
| select X86_CPU_HAS_SSE2 |
| select X86_MMX |
| select X86_SSE |
| select X86_SSE2 |
| |
| menu "x86 Features" |
| |
| config X86_CPU_HAS_MMX |
| bool |
| |
| config X86_CPU_HAS_SSE |
| bool |
| |
| config X86_CPU_HAS_SSE2 |
| bool |
| |
| config X86_CPU_HAS_SSE3 |
| bool |
| |
| config X86_CPU_HAS_SSSE3 |
| bool |
| |
| config X86_CPU_HAS_SSE41 |
| bool |
| |
| config X86_CPU_HAS_SSE42 |
| bool |
| |
| config X86_CPU_HAS_SSE4A |
| bool |
| |
| if FPU || X86_64 |
| |
| config X86_MMX |
| bool "MMX Support" |
| depends on X86_CPU_HAS_MMX |
| help |
| This option enables MMX support, and the use of MMX registers |
| by threads. |
| |
| config X86_SSE |
| bool "SSE Support" |
| depends on X86_CPU_HAS_SSE |
| help |
| This option enables SSE support, and the use of SSE registers |
| by threads. |
| |
| config X86_SSE2 |
| bool "SSE2 Support" |
| depends on X86_CPU_HAS_SSE2 |
| select X86_SSE |
| help |
| This option enables SSE2 support. |
| |
| config X86_SSE3 |
| bool "SSE3 Support" |
| depends on X86_CPU_HAS_SSE3 |
| select X86_SSE |
| help |
| This option enables SSE3 support. |
| |
| config X86_SSSE3 |
| bool "SSSE3 (Supplemental SSE3) Support" |
| depends on X86_CPU_HAS_SSSE3 |
| select X86_SSE |
| help |
| This option enables Supplemental SSE3 support. |
| |
| config X86_SSE41 |
| bool "SSE4.1 Support" |
| depends on X86_CPU_HAS_SSE41 |
| select X86_SSE |
| help |
| This option enables SSE4.1 support. |
| |
| config X86_SSE42 |
| bool "SSE4.2 Support" |
| depends on X86_CPU_HAS_SSE42 |
| select X86_SSE |
| help |
| This option enables SSE4.2 support. |
| |
| config X86_SSE4A |
| bool "SSE4A Support" |
| depends on X86_CPU_HAS_SSE4A |
| select X86_SSE |
| help |
| This option enables SSE4A support. |
| |
| config X86_SSE_FP_MATH |
| bool "Compiler-generated SSEx instructions for floating point math" |
| depends on X86_SSE |
| help |
| This option allows the compiler to generate SSEx instructions for |
| performing floating point math. This can greatly improve performance |
| when exactly the same operations are to be performed on multiple |
| data objects; however, it can also significantly reduce performance |
| when preemptive task switches occur because of the larger register |
| set that must be saved and restored. |
| |
| Disabling this option means that the compiler utilizes only the |
| x87 instruction set for floating point operations. |
| |
| endif # FPU || X86_64 |
| |
| endmenu |
| |
| config SRAM_OFFSET |
| default 0x100000 if X86_PC_COMPATIBLE |
| help |
| A lot of x86 that resemble PCs have many reserved physical memory |
| regions within the first megabyte. Specify an offset from the |
| beginning of RAM to load the kernel in physical memory, avoiding these |
| regions. |
| |
| Note that this does not include the "locore" which contains real mode |
| bootstrap code within the first 64K of physical memory. |
| |
| This value normally need to be page-aligned. |
| |
| config KERNEL_VM_OFFSET |
| default 0x100000 if MMU |
| |
| config MAX_IRQ_LINES |
| int "Number of IRQ lines" |
| default 128 |
| range 0 224 |
| help |
| This option specifies the number of IRQ lines in the system. It |
| determines the size of the _irq_to_interrupt_vector_table, which |
| is used to track the association between vectors and IRQ numbers. |
| |
| config IRQ_OFFLOAD_VECTOR |
| int "IDT vector to use for IRQ offload" |
| default 33 |
| range 32 255 |
| depends on IRQ_OFFLOAD |
| |
| config PIC_DISABLE |
| bool "Disable PIC" |
| help |
| This option disables all interrupts on the legacy i8259 PICs at boot. |
| |
| choice |
| prompt "Reboot implementation" |
| depends on REBOOT |
| default REBOOT_RST_CNT |
| |
| config REBOOT_RST_CNT |
| bool "Reboot via RST_CNT register" |
| help |
| Reboot via the RST_CNT register, going back to BIOS. |
| endchoice |
| |
| config PCIE_MMIO_CFG |
| bool "Use MMIO PCI configuration space access" |
| select ACPI |
| help |
| Selects the use of the memory-mapped PCI Express Extended |
| Configuration Space instead of the traditional 0xCF8/0xCFC |
| IO Port registers. |
| |
| config KERNEL_VM_SIZE |
| default 0x40000000 if ACPI |
| |
| config X86_PC_COMPATIBLE |
| bool |
| default y |
| select ARCH_HAS_RESERVED_PAGE_FRAMES |
| select HAS_SRAM_OFFSET |
| help |
| Hidden option to signal building for PC-compatible platforms |
| with BIOS, ACPI, etc. |
| |
| config X86_MEMMAP |
| bool "Use memory map" |
| select ARCH_HAS_RESERVED_PAGE_FRAMES |
| help |
| Enable the use of memory map to identify regions of memory. |
| |
| The memory map can be populated via Multiboot |
| (CONFIG_MULTIBOOT=y and CONFIG_MULTIBOOT_MEMMAP=y) or |
| can be manually defined via x86_memmap[]. |
| |
| config X86_MEMMAP_ENTRIES |
| int "Number of memory map entries" |
| depends on X86_MEMMAP |
| range 1 256 |
| default 1 if !MULTIBOOT_MEMMAP |
| default 64 if MULTIBOOT_MEMMAP |
| help |
| Maximum number of memory regions to hold in the memory map. |
| |
| config MULTIBOOT |
| bool "Generate multiboot header" |
| depends on X86_PC_COMPATIBLE |
| default y |
| help |
| Embed a multiboot header in the output executable. This is used |
| by some boot loaders (e.g., GRUB) when loading Zephyr. It is safe |
| to leave this option on if you're not sure. It only expands the |
| text segment by 12-16 bytes and is typically ignored if not needed. |
| |
| if MULTIBOOT |
| |
| config MULTIBOOT_INFO |
| bool "Preserve multiboot information structure" |
| help |
| Multiboot passes a pointer to an information structure to the |
| kernel entry point. Some drivers (e.g., the multiboot framebuffer |
| display driver) need to refer to information in this structure, |
| and so set this option to preserve the data in a permanent location. |
| |
| config MULTIBOOT_MEMMAP |
| bool "Use multiboot memory map if provided" |
| select MULTIBOOT_INFO |
| select X86_MEMMAP |
| help |
| Use the multiboot memory map if the loader provides one. |
| |
| endif # MULTIBOOT |
| |
| config X86_VERY_EARLY_CONSOLE |
| bool "Support very early boot printk" |
| depends on PRINTK |
| help |
| Non-emulated X86 devices often require special hardware to attach |
| a debugger, which may not be easily available. This option adds a |
| very minimal serial driver which gets initialized at the very |
| beginning of z_cstart(), via arch_kernel_init(). This driver enables |
| printk to emit messages to the 16550 UART port 0 instance in device |
| tree. This mini-driver assumes I/O to the UART is done via ports. |
| |
| config X86_MMU |
| bool "Memory Management Unit" |
| select MMU |
| help |
| This options enables the memory management unit present in x86 |
| and creates a set of page tables at boot time that is runtime- |
| mutable. |
| |
| config X86_COMMON_PAGE_TABLE |
| bool "Use a single page table for all threads" |
| default n |
| depends on USERSPACE |
| depends on !SMP |
| depends on !X86_KPTI |
| help |
| If this option is enabled, userspace memory domains will not have their |
| own page tables. Instead, context switching operations will modify |
| page tables in place. This is much slower, but uses much less RAM |
| for page tables. |
| |
| config X86_MAX_ADDITIONAL_MEM_DOMAINS |
| int "Maximum number of memory domains" |
| default 3 |
| depends on X86_MMU && USERSPACE && !X86_COMMON_PAGE_TABLE |
| help |
| The initial page tables at boot are pre-allocated, and used for the |
| default memory domain. Instantiation of additional memory domains |
| if common page tables are in use requires a pool of free pinned |
| memory pages for constructing page tables. |
| |
| Zephyr test cases assume 3 additional domains can be instantiated. |
| |
| config X86_EXTRA_PAGE_TABLE_PAGES |
| int "Reserve extra pages in page table" |
| default 1 if X86_PAE && (KERNEL_VM_BASE != SRAM_BASE_ADDRESS) |
| default 0 |
| depends on X86_MMU |
| help |
| The whole page table is pre-allocated at build time and is |
| dependent on the range of address space. This allows reserving |
| extra pages (of size CONFIG_MMU_PAGE_SIZE) to the page table |
| so that gen_mmu.py can make use of these extra pages. |
| |
| Says 0 unless absolutely sure that this is necessary. |
| |
| config X86_NO_MELTDOWN |
| bool |
| help |
| This hidden option should be set on a per-SOC basis to indicate that |
| a particular SOC is not vulnerable to the Meltdown CPU vulnerability, |
| as described in CVE-2017-5754. |
| |
| config X86_NO_SPECTRE_V1 |
| bool |
| help |
| This hidden option should be set on a per-SOC basis to indicate that |
| a particular SOC is not vulnerable to the Spectre V1, V1.1, V1.2, and |
| swapgs CPU vulnerabilities as described in CVE-2017-5753, |
| CVE-2018-3693, and CVE-2019-1125. |
| |
| config X86_NO_SPECTRE_V2 |
| bool |
| help |
| This hidden option should be set on a per-SOC basis to indicate that |
| a particular SOC is not vulnerable to the Spectre V2 CPU |
| vulnerability, as described in CVE-2017-5715. |
| |
| config X86_NO_SPECTRE_V4 |
| bool |
| help |
| This hidden option should be set on a per-SOC basis to indicate that |
| a particular SOC is not vulnerable to the Spectre V4 CPU |
| vulnerability, as described in CVE-2018-3639. |
| |
| config X86_NO_LAZY_FP |
| bool |
| help |
| This hidden option should be set on a per-SOC basis to indicate |
| that a particular SOC is not vulnerable to the Lazy FP CPU |
| vulnerability, as described in CVE-2018-3665. |
| |
| config X86_NO_SPECULATIVE_VULNERABILITIES |
| bool |
| select X86_NO_MELTDOWN |
| select X86_NO_SPECTRE_V1 |
| select X86_NO_SPECTRE_V2 |
| select X86_NO_SPECTRE_V4 |
| select X86_NO_LAZY_FP |
| help |
| This hidden option should be set on a per-SOC basis to indicate that |
| a particular SOC does not perform any kind of speculative execution, |
| or is a newer chip which is immune to the class of vulnerabilities |
| which exploit speculative execution side channel attacks. |
| |
| config DISABLE_SSBD |
| bool "Disable Speculative Store Bypass" |
| depends on USERSPACE |
| default y if !X86_NO_SPECTRE_V4 |
| help |
| This option will disable Speculative Store Bypass in order to |
| mitigate against certain kinds of side channel attacks. Quoting |
| the "Speculative Execution Side Channels" document, version 2.0: |
| |
| When SSBD is set, loads will not execute speculatively |
| until the addresses of all older stores are known. This |
| ensure s that a load does not speculatively consume stale |
| data values due to bypassing an older store on the same |
| logical processor. |
| |
| If enabled, this applies to all threads in the system. |
| |
| Even if enabled, will have no effect on CPUs that do not |
| require this feature. |
| |
| config ENABLE_EXTENDED_IBRS |
| bool "Extended IBRS" |
| depends on USERSPACE |
| default y if !X86_NO_SPECTRE_V2 |
| help |
| This option will enable the Extended Indirect Branch Restricted |
| Speculation 'always on' feature. This mitigates Indirect Branch |
| Control vulnerabilities (aka Spectre V2). |
| |
| config X86_BOUNDS_CHECK_BYPASS_MITIGATION |
| bool |
| depends on USERSPACE |
| default y if !X86_NO_SPECTRE_V1 |
| select BOUNDS_CHECK_BYPASS_MITIGATION |
| help |
| Hidden config to select arch-independent option to enable |
| Spectre V1 mitigations by default if the CPU is not known |
| to be immune to it. |
| |
| config X86_KPTI |
| bool "Kernel page table isolation" |
| default y |
| depends on USERSPACE |
| depends on !X86_NO_MELTDOWN |
| help |
| Implements kernel page table isolation to mitigate Meltdown exploits |
| to read Kernel RAM. Incurs a significant performance cost for |
| user thread interrupts and system calls, and significant footprint |
| increase for additional page tables and trampoline stacks. |
| |
| config X86_EFI |
| bool "EFI" |
| default y |
| depends on BUILD_OUTPUT_EFI |
| help |
| Enable EFI support. This means you build your image with zefi |
| support. See arch/x86/zefi/README.txt for more information. |
| |
| config X86_EFI_CONSOLE |
| bool |
| depends on X86_EFI && X86_64 && !X86_VERY_EARLY_CONSOLE |
| select EFI_CONSOLE |
| default y if !UART_CONSOLE |
| help |
| This enables the use of the UEFI console device as the |
| Zephyr printk handler. It requires that no interferences |
| with hardware used by the firmware console (e.g. a UART or |
| framebuffer) happens from Zephyr code, and that all memory |
| used by the firmware environment and its page tables be |
| separate and preserved. In general this is safe to assume, |
| but no automatic checking exists at runtime to verify. |
| Likewise be sure to disable any other console/printk |
| drivers! |
| |
| source "arch/x86/core/Kconfig.ia32" |
| source "arch/x86/core/Kconfig.intel64" |
| |
| endmenu |
