FreeBSD/Linux Kernel Cross Reference
sys/amd64/conf/NOTES

     #
     # NOTES -- Lines that can be cut/pasted into kernel and hints configs.
     #
     # This file contains machine dependent kernel configuration notes.  For
     # machine independent notes, look in /sys/conf/NOTES.
     #
     # $FreeBSD$
     #
     
    #
    # Enable the kernel DTrace hooks which are required to load the DTrace
    # kernel modules.
    #
    options         KDTRACE_HOOKS
    
    # DTrace core
    # NOTE: introduces CDDL-licensed components into the kernel
    #device         dtrace
    
    # DTrace modules
    #device         dtrace_profile
    #device         dtrace_sdt
    #device         dtrace_fbt
    #device         dtrace_systrace
    #device         dtrace_prototype
    #device         dtnfscl
    #device         dtmalloc
    
    # Alternatively include all the DTrace modules
    #device         dtraceall
    
    
    #####################################################################
    # SMP OPTIONS:
    #
    # Notes:
    #
    # IPI_PREEMPTION instructs the kernel to preempt threads running on other
    #         CPUS if needed.  Relies on the PREEMPTION option
    
    # Optional:
    options         IPI_PREEMPTION
    device          atpic                   # Optional legacy pic support
    device          mptable                 # Optional MPSPEC mptable support
    
    # Debugging options.
    #
    options         COUNT_XINVLTLB_HITS     # Counters for TLB events
    options         COUNT_IPIS              # Per-CPU IPI interrupt counters
    
    
    
    #####################################################################
    # CPU OPTIONS
    
    #
    # You must specify at least one CPU (the one you intend to run on);
    # deleting the specification for CPUs you don't need to use may make
    # parts of the system run faster.
    #
    cpu             HAMMER                  # aka K8, aka Opteron & Athlon64
    
    #
    # Options for CPU features.
    #
    
    
    #####################################################################
    # NETWORKING OPTIONS
    
    #
    # DEVICE_POLLING adds support for mixed interrupt-polling handling
    # of network device drivers, which has significant benefits in terms
    # of robustness to overloads and responsivity, as well as permitting
    # accurate scheduling of the CPU time between kernel network processing
    # and other activities.  The drawback is a moderate (up to 1/HZ seconds)
    # potential increase in response times.
    # It is strongly recommended to use HZ=1000 or 2000 with DEVICE_POLLING
    # to achieve smoother behaviour.
    # Additionally, you can enable/disable polling at runtime with help of
    # the ifconfig(8) utility, and select the CPU fraction reserved to
    # userland with the sysctl variable kern.polling.user_frac
    # (default 50, range 0..100).
    #
    # Not all device drivers support this mode of operation at the time of
    # this writing.  See polling(4) for more details.
    
    options         DEVICE_POLLING
    
    # BPF_JITTER adds support for BPF just-in-time compiler.
    
    options         BPF_JITTER
    
    # OpenFabrics Enterprise Distribution (Infiniband).
    options         OFED
    options         OFED_DEBUG_INIT
    
    # Sockets Direct Protocol
    options         SDP
   options         SDP_DEBUG
   
   # IP over Infiniband
   options         IPOIB
   options         IPOIB_DEBUG
   options         IPOIB_CM
   
   
   #####################################################################
   # CLOCK OPTIONS
   
   # Provide read/write access to the memory in the clock chip.
   device          nvram           # Access to rtc cmos via /dev/nvram
   
   
   #####################################################################
   # MISCELLANEOUS DEVICES AND OPTIONS
   
   device          speaker         #Play IBM BASIC-style noises out your speaker
   envvar          hint.speaker.0.at="isa"
   envvar          hint.speaker.0.port="0x61"
   
   
   #####################################################################
   # HARDWARE BUS CONFIGURATION
   
   #
   # ISA bus
   #
   device          isa
   
   #
   # Options for `isa':
   #
   # AUTO_EOI_1 enables the `automatic EOI' feature for the master 8259A
   # interrupt controller.  This saves about 0.7-1.25 usec for each interrupt.
   # This option breaks suspend/resume on some portables.
   #
   # AUTO_EOI_2 enables the `automatic EOI' feature for the slave 8259A
   # interrupt controller.  This saves about 0.7-1.25 usec for each interrupt.
   # Automatic EOI is documented not to work for the slave with the
   # original i8259A, but it works for some clones and some integrated
   # versions.
   #
   # MAXMEM specifies the amount of RAM on the machine; if this is not
   # specified, FreeBSD will first read the amount of memory from the CMOS
   # RAM, so the amount of memory will initially be limited to 64MB or 16MB
   # depending on the BIOS.  If the BIOS reports 64MB, a memory probe will
   # then attempt to detect the installed amount of RAM.  If this probe
   # fails to detect >64MB RAM you will have to use the MAXMEM option.
   # The amount is in kilobytes, so for a machine with 128MB of RAM, it would
   # be 131072 (128 * 1024).
   #
   # BROKEN_KEYBOARD_RESET disables the use of the keyboard controller to
   # reset the CPU for reboot.  This is needed on some systems with broken
   # keyboard controllers.
   
   options         AUTO_EOI_1
   #options        AUTO_EOI_2
   
   options         MAXMEM=(128*1024)
   #options        BROKEN_KEYBOARD_RESET
   
   #
   # AGP GART support
   device          agp
   
   #
   # AGP debugging.
   #
   options         AGP_DEBUG
   
   
   #####################################################################
   # HARDWARE DEVICE CONFIGURATION
   
   # To include support for VGA VESA video modes
   options         VESA
   
   # Turn on extra debugging checks and output for VESA support.
   options         VESA_DEBUG
   
   device          dpms            # DPMS suspend & resume via VESA BIOS
   
   # x86 real mode BIOS emulator, required by atkbdc/dpms/vesa
   options         X86BIOS
   
   #
   # Optional devices:
   #
   
   # PS/2 mouse
   device          psm
   envvar          hint.psm.0.at="atkbdc"
   envvar          hint.psm.0.irq="12"
   
   # Options for psm:
   options         PSM_HOOKRESUME          #hook the system resume event, useful
                                           #for some laptops
   options         PSM_RESETAFTERSUSPEND   #reset the device at the resume event
   
   # The keyboard controller; it controls the keyboard and the PS/2 mouse.
   device          atkbdc
   envvar          hint.atkbdc.0.at="isa"
   envvar          hint.atkbdc.0.port="0x060"
   
   # The AT keyboard
   device          atkbd
   envvar          hint.atkbd.0.at="atkbdc"
   envvar          hint.atkbd.0.irq="1"
   
   # Options for atkbd:
   options         ATKBD_DFLT_KEYMAP       # specify the built-in keymap
   makeoptions     ATKBD_DFLT_KEYMAP=fr.dvorak
   
   # `flags' for atkbd:
   #       0x01    Force detection of keyboard, else we always assume a keyboard
   #       0x02    Don't reset keyboard, useful for some newer ThinkPads
   #       0x03    Force detection and avoid reset, might help with certain
   #               dockingstations
   #       0x04    Old-style (XT) keyboard support, useful for older ThinkPads
   
   # Video card driver for VGA adapters.
   device          vga
   envvar          hint.vga.0.at="isa"
   
   # Options for vga:
   # Try the following option if the mouse pointer is not drawn correctly
   # or font does not seem to be loaded properly.  May cause flicker on
   # some systems.
   options         VGA_ALT_SEQACCESS
   
   # If you can dispense with some vga driver features, you may want to
   # use the following options to save some memory.
   #options        VGA_NO_FONT_LOADING     # don't save/load font
   #options        VGA_NO_MODE_CHANGE      # don't change video modes
   
   # Older video cards may require this option for proper operation.
   options         VGA_SLOW_IOACCESS       # do byte-wide i/o's to TS and GDC regs
   
   # The following option probably won't work with the LCD displays.
   options         VGA_WIDTH90             # support 90 column modes
   
   # Debugging.
   options         VGA_DEBUG
   
   # vt(4) drivers.
   device          vt_vga          # VGA
   device          vt_efifb        # EFI framebuffer
   device          vt_vbefb        # VBE framebuffer
   
   # Linear framebuffer driver for S3 VESA 1.2 cards. Works on top of VESA.
   device          s3pci
   
   # 3Dfx Voodoo Graphics, Voodoo II /dev/3dfx CDEV support.  This will create
   # the /dev/3dfx0 device to work with glide implementations.  This should get
   # linked to /dev/3dfx and /dev/voodoo.  Note that this is not the same as
   # the tdfx DRI module from XFree86 and is completely unrelated.
   #
   
   device          tdfx                    # Enable 3Dfx Voodoo support
   
   #
   # ACPI support using the Intel ACPI Component Architecture reference
   # implementation.
   #
   # ACPI_DEBUG enables the use of the debug.acpi.level and debug.acpi.layer
   # kernel environment variables to select initial debugging levels for the
   # Intel ACPICA code.  (Note that the Intel code must also have USE_DEBUGGER
   # defined when it is built).
   
   device          acpi
   options         ACPI_DEBUG
   
   # The cpufreq(4) driver provides support for non-ACPI CPU frequency control
   device          cpufreq
   
   #
   # Network interfaces:
   #
   
   # axp: AMD EPYC integrated NIC
   #       Requires the miibus module
   # bxe:  Broadcom NetXtreme II (BCM5771X/BCM578XX) PCIe 10Gb Ethernet
   #       adapters.
   # ice:  Intel 800 Series Physical Function
   #       Requires the ice_ddp module for full functionality
   # igc:  Intel I225 2.5Gb Ethernet adapter
   # ipw:  Intel PRO/Wireless 2100 IEEE 802.11 adapter
   #       Requires the ipw firmware module
   # irdma: Intel 800 Series RDMA driver
   #        Requires the ice module
   # iwi:  Intel PRO/Wireless 2200BG/2225BG/2915ABG IEEE 802.11 adapters
   #       Requires the iwi firmware module
   # iwn:  Intel Wireless WiFi Link 1000/105/135/2000/4965/5000/6000/6050 abgn
   #       802.11 network adapters
   #       Requires the iwn firmware module
   # mthca: Mellanox HCA InfiniBand
   # mlx4ib: Mellanox ConnectX HCA InfiniBand
   # mlx4en: Mellanox ConnectX HCA Ethernet
   # nfe:  nVidia nForce MCP on-board Ethernet Networking (BSD open source)
   # qlxgb: QLogic 3200 and 8200 series 10 Gigabit Ethernet & CNA Adapter
   # qlxgbe: QLogic 8300 series 10 Gigabit Ethernet & CNA Adapter
   # qlxge: QLogic 8100 series 10 Gigabit Ethernet & CNA Adapter
   # sfxge: Solarflare SFC9000 family 10Gb Ethernet adapters
   # vmx:  VMware VMXNET3 Ethernet (BSD open source)
   # wpi:  Intel 3945ABG Wireless LAN controller
   #       Requires the wpi firmware module
   
   device          axp             # AMD EPYC integrated NIC
   device          bxe             # Broadcom NetXtreme II BCM5771X/BCM578XX 10GbE
   device          igc             # Intel I225 2.5G Ethernet
   device          ipw             # Intel 2100 wireless NICs.
   device          iwi             # Intel 2200BG/2225BG/2915ABG wireless NICs.
   device          iwn             # Intel 4965/1000/5000/6000 wireless NICs.
   device          ixl             # Intel 700 Series Physical Function
   device          iavf            # Intel Adaptive Virtual Function
   device          ice             # Intel 800 Series Physical Function
   device          ice_ddp         # Intel 800 Series DDP Package
   device          irdma           # Intel 800 Series RDMA driver
   device          mthca           # Mellanox HCA InfiniBand
   device          mlx4            # Shared code module between IB and Ethernet
   device          mlx4ib          # Mellanox ConnectX HCA InfiniBand
   device          mlx4en          # Mellanox ConnectX HCA Ethernet
   device          nfe             # nVidia nForce MCP on-board Ethernet
   device          qlxgb           # QLogic 3200/8200 Ethernet
   device          qlxgbe          # QLogic 8300 Ethernet
   device          qlxge           # QLogic 8100 Ethernet
   device          sfxge           # Solarflare SFC9000 10Gb Ethernet
   device          vmx             # VMware VMXNET3 Ethernet
   device          wpi             # Intel 3945ABG wireless NICs.
   
   # IEEE 802.11 adapter firmware modules
   
   # Intel PRO/Wireless 2100 firmware:
   #   ipwfw:              BSS/IBSS/monitor mode firmware
   #   ipwbssfw:           BSS mode firmware
   #   ipwibssfw:          IBSS mode firmware
   #   ipwmonitorfw:       Monitor mode firmware
   # Intel PRO/Wireless 2200BG/2225BG/2915ABG firmware:
   #   iwifw:              BSS/IBSS/monitor mode firmware
   #   iwibssfw:           BSS mode firmware
   #   iwiibssfw:          IBSS mode firmware
   #   iwimonitorfw:       Monitor mode firmware
   # Intel Wireless WiFi Link 4965/1000/5000/6000 series firmware:
   #   iwnfw:              Single module to support all devices
   #   iwn1000fw:          Specific module for the 1000 only
   #   iwn105fw:           Specific module for the 105 only
   #   iwn135fw:           Specific module for the 135 only
   #   iwn2000fw:          Specific module for the 2000 only
   #   iwn2030fw:          Specific module for the 2030 only
   #   iwn4965fw:          Specific module for the 4965 only
   #   iwn5000fw:          Specific module for the 5000 only
   #   iwn5150fw:          Specific module for the 5150 only
   #   iwn6000fw:          Specific module for the 6000 only
   #   iwn6000g2afw:       Specific module for the 6000g2a only
   #   iwn6000g2bfw:       Specific module for the 6000g2b only
   #   iwn6050fw:          Specific module for the 6050 only
   # wpifw:        Intel 3945ABG Wireless LAN Controller firmware
   
   device          iwifw
   device          iwibssfw
   device          iwiibssfw
   device          iwimonitorfw
   device          ipwfw
   device          ipwbssfw
   device          ipwibssfw
   device          ipwmonitorfw
   device          iwnfw
   device          iwn1000fw
   device          iwn105fw
   device          iwn135fw
   device          iwn2000fw
   device          iwn2030fw
   device          iwn4965fw
   device          iwn5000fw
   device          iwn5150fw
   device          iwn6000fw
   device          iwn6000g2afw
   device          iwn6000g2bfw
   device          iwn6050fw
   device          wpifw
   
   # net80211 options
   options         IEEE80211_DEBUG_REFCNT
   
   #
   # Non-Transparent Bridge (NTB) drivers
   #
   device          if_ntb          # Virtual NTB network interface
   device          ntb_transport   # NTB packet transport driver
   device          ntb             # NTB hardware interface
   device          ntb_hw_amd      # AMD NTB hardware driver
   device          ntb_hw_intel    # Intel NTB hardware driver
   device          ntb_hw_plx      # PLX NTB hardware driver
   
   #
   #XXX this stores pointers in a 32bit field that is defined by the hardware
   #device pst
   
   #
   # Areca 11xx and 12xx series of SATA II RAID controllers.
   # CAM is required.
   #
   device          arcmsr          # Areca SATA II RAID
   
   #
   # Microsemi smartpqi controllers.
   # These controllers have a SCSI-like interface, and require the
   # CAM infrastructure.
   #
   device          smartpqi
   
   #
   # Adaptec FSA RAID controllers, including integrated DELL controllers,
   # the Dell PERC 2/QC and the HP NetRAID-4M
   device          aac
   device          aacp    # SCSI Passthrough interface (optional, CAM required)
   
   #
   # Highpoint RocketRAID 27xx.
   device          hpt27xx
   
   #
   # Highpoint RocketRAID 182x.
   device          hptmv
   
   #
   # Highpoint DC7280 and R750.
   device          hptnr
   
   #
   # Highpoint RocketRAID.  Supports RR172x, RR222x, RR2240, RR232x, RR2340,
   # RR2210, RR174x, RR2522, RR231x, RR230x.
   device          hptrr
   
   #
   # Highpoint RocketRaid 3xxx series SATA RAID
   device          hptiop
   
   #
   # IBM (now Adaptec) ServeRAID controllers
   device          ips
   
   #
   # Intel integrated Memory Controller (iMC) SMBus controller
   #       Sandybridge-Xeon, Ivybridge-Xeon, Haswell-Xeon, Broadwell-Xeon
   device          imcsmb
   
   #
   # Intel C600 (Patsburg) integrated SAS controller
   device          isci
   options         ISCI_LOGGING    # enable debugging in isci HAL
   
   #
   # NVM Express (NVMe) support
   device         nvme    # base NVMe driver
   device         nvd     # expose NVMe namespaces as disks, depends on nvme
   
   #
   # Intel Volume Management Device (VMD) support
   device          vmd
   
   #
   # PMC-Sierra SAS/SATA controller
   device          pmspcv
   
   #
   # Intel QuickAssist driver with OpenCrypto support
   #
   # Only for legacy Atom C2XXX chipsets.
   device          qat_c2xxx
   
   #
   # SafeNet crypto driver: can be moved to the MI NOTES as soon as
   # it's tested on a big-endian machine
   #
   device          safe            # SafeNet 1141
   options         SAFE_DEBUG      # enable debugging support: hw.safe.debug
   options         SAFE_RNDTEST    # enable rndtest support
   
   #
   # VirtIO support
   #
   # The virtio entry provides a generic bus for use by the device drivers.
   # It must be combined with an interface that communicates with the host.
   # Multiple such interfaces are defined by the VirtIO specification. FreeBSD
   # only has support for PCI. Therefore, virtio_pci must be statically
   # compiled in or loaded as a module for the device drivers to function.
   #
   device          virtio          # Generic VirtIO bus (required)
   device          virtio_pci      # VirtIO PCI Interface
   device          vtnet           # VirtIO Ethernet device
   device          virtio_blk      # VirtIO Block device
   device          virtio_scsi     # VirtIO SCSI device
   device          virtio_balloon  # VirtIO Memory Balloon device
   device          virtio_random   # VirtIO Entropy device
   device          virtio_console  # VirtIO Console device
   
   # Linux KVM paravirtualization support
   device          kvm_clock       # KVM paravirtual clock driver
   
   # Microsoft Hyper-V enhancement support
   device          hyperv          # HyperV drivers
   
   # Xen HVM Guest Optimizations
   options         XENHVM          # Xen HVM kernel infrastructure
   device          xenpci          # Xen HVM Hypervisor services driver
   device          xentimer        # Xen x86 PV timer device
   
   #####################################################################
   
   #
   # Miscellaneous hardware:
   #
   # ipmi: Intelligent Platform Management Interface
   # pbio: Parallel (8255 PPI) basic I/O (mode 0) port (e.g. Advantech PCL-724)
   # smbios: DMI/SMBIOS entry point (requires EFIRT option)
   # vpd: Vital Product Data kernel interface
   # asmc: Apple System Management Controller
   # si: Specialix International SI/XIO or SX intelligent serial card
   # tpm: Trusted Platform Module
   
   # Notes on the Specialix SI/XIO driver:
   #  The host card is memory, not IO mapped.
   #  The Rev 1 host cards use a 64K chunk, on a 32K boundary.
   #  The Rev 2 host cards use a 32K chunk, on a 32K boundary.
   #  The cards can use an IRQ of 11, 12 or 15.
   
   device          ipmi
   device          pbio
   envvar          hint.pbio.0.at="isa"
   envvar          hint.pbio.0.port="0x360"
   device          smbios
   device          vpd
   device          asmc
   device          tpm
   device          padlock_rng     # VIA Padlock RNG
   device          rdrand_rng      # Intel Bull Mountain RNG
   device          aesni           # AES-NI OpenCrypto module
   device          ossl            # OpenSSL OpenCrypto module
   device          ioat            # Intel I/OAT DMA engine
   
   #
   # Laptop/Notebook options:
   #
   
   device backlight
   
   #
   # I2C Bus
   #
   
   #
   # Hardware watchdog timers:
   #
   # ichwd: Intel ICH watchdog timer
   # amdsbwd: AMD SB7xx watchdog timer
   # viawd: VIA south bridge watchdog timer
   # wbwd: Winbond watchdog timer
   # itwd: ITE Super I/O watchdog timer
   #
   device          ichwd
   device          amdsbwd
   device          viawd
   device          wbwd
   device          itwd
   
   #
   # Temperature sensors:
   #
   # coretemp: on-die sensor on Intel Core and newer CPUs
   # amdtemp: on-die sensor on AMD K8/K10/K11 CPUs
   #
   device          coretemp
   device          amdtemp
   
   #
   # CPU control pseudo-device. Provides access to MSRs, CPUID info and
   # microcode update feature.
   #
   device          cpuctl
   
   #
   # SuperIO driver.
   #
   device          superio
   
   #
   # System Management Bus (SMB)
   #
   options         ENABLE_ALART            # Control alarm on Intel intpm driver
   
   #
   # AMD System Management Network (SMN)
   #
   device          amdsmn
   
   #
   # Number of initial kernel page table pages used for early bootstrap.
   # This number should include enough pages to map the kernel and any
   # modules or other data loaded with the kernel by the loader.  Each
   # page table page maps 2MB.
   #
   options         NKPT=31
   
   # EFI Runtime Services support
   options         EFIRT
   
   #
   # HID-over-I2C support
   #
   device          iichid          # HID-over-I2C support
   options         IICHID_DEBUG    # Enable HID-over-I2C debug messages
   options         IICHID_SAMPLING # Workaround missing GPIO INTR support
   
   #####################################################################
   # ABI Emulation
   
   #XXX keep these here for now and reactivate when support for emulating
   #XXX these 32 bit binaries is added.
   
   # Enable 32-bit runtime support for FreeBSD/i386 binaries.
   options         COMPAT_FREEBSD32
   
   # Enable (32-bit) a.out binary support
   options         COMPAT_AOUT
   
   #####################################################################
   # ZFS support
   
   # NB: This depends on crypto, cryptodev and ZSTDIO
   options         ZFS
   
   #####################################################################
   # VM OPTIONS
   
   # KSTACK_PAGES is the number of memory pages to assign to the kernel
   # stack of each thread.
   
   options         KSTACK_PAGES=5
   
   # Enable detailed accounting by the PV entry allocator.
   
   options         PV_STATS
   
   #####################################################################
   
   # More undocumented options for linting.
   # Note that documenting these are not considered an affront.
   
   options         KBDIO_DEBUG=2
   options         KBD_MAXRETRY=4
   options         KBD_MAXWAIT=6
   options         KBD_RESETDELAY=201
   
   options         PSM_DEBUG=1
   
   options         TIMER_FREQ=((14318182+6)/12)
   
   options         VM_KMEM_SIZE
   options         VM_KMEM_SIZE_MAX
   options         VM_KMEM_SIZE_SCALE
   
   # GCOV (code coverage) support
   
   options         LINDEBUGFS
   options         GCOV

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