tech/config/kernel.jd

page.title=Kernel Configuration
@jd:body

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<div id="qv-wrapper">
  <div id="qv">
    <h2>In this document</h2>
    <ol id="auto-toc">
    </ol>
  </div>
</div>

<p>The kernel configuration settings in this document are meant to be used as a
base for an Android kernel configuration. All devices should have the options
in android-base configuration enabled. While not mandatory, the options in
android-recommended configuration enable advanced Android
features.</p>

<p>
Generating kernel config: Assuming you already have a minimalist defconfig for your device, a possible
way to enable these options would be:</p>

<pre>ARCH=<arch> scripts/kconfig/merge_config.sh <path_to>/<device>_defconfig android/configs/android-base.cfg
android/configs/android-recommended.cfg</pre>
<p>
This will generate a .config that can then be used to save a new defconfig or
compile a new kernel with Android features enabled.
</p>
<h3 id="base">
Base Configuration
</h3>
<pre>
CONFIG_EXPERIMENTAL=y
CONFIG_SYSVIPC=y
CONFIG_CGROUPS=y
CONFIG_CGROUP_DEBUG=y
CONFIG_CGROUP_FREEZER=y
CONFIG_CGROUP_CPUACCT=y
CONFIG_RESOURCE_COUNTERS=y
CONFIG_CGROUP_SCHED=y
CONFIG_RT_GROUP_SCHED=y
CONFIG_BLK_DEV_INITRD=y
CONFIG_EMBEDDED=y
CONFIG_NO_HZ=y
CONFIG_HIGH_RES_TIMERS=y
CONFIG_PREEMPT=y
CONFIG_PM_AUTOSLEEP=y
CONFIG_PM_WAKELOCKS=y
CONFIG_BLK_DEV_DM=y
CONFIG_DM_CRYPT=y
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
CONFIG_XFRM_USER=y
CONFIG_NET_KEY=y
CONFIG_INET=y
CONFIG_IP_ADVANCED_ROUTER=y
CONFIG_IP_MULTIPLE_TABLES=y
CONFIG_INET_ESP=y
# CONFIG_INET_LRO is not set
CONFIG_IPV6_PRIVACY=y
CONFIG_IPV6_ROUTER_PREF=y
CONFIG_IPV6_OPTIMISTIC_DAD=y
CONFIG_INET6_AH=y
CONFIG_INET6_ESP=y
CONFIG_INET6_IPCOMP=y
CONFIG_IPV6_MIP6=y
CONFIG_IPV6_MULTIPLE_TABLES=y
CONFIG_NETFILTER=y
CONFIG_NF_CONNTRACK=y
CONFIG_NF_CONNTRACK_EVENTS=y
CONFIG_NF_CT_PROTO_DCCP=y
CONFIG_NF_CT_PROTO_SCTP=y
CONFIG_NF_CT_PROTO_UDPLITE=y
CONFIG_NF_CONNTRACK_AMANDA=y
CONFIG_NF_CONNTRACK_FTP=y
CONFIG_NF_CONNTRACK_H323=y
CONFIG_NF_CONNTRACK_IRC=y
CONFIG_NF_CONNTRACK_NETBIOS_NS=y
CONFIG_NF_CONNTRACK_PPTP=y
CONFIG_NF_CONNTRACK_SANE=y
CONFIG_NF_CONNTRACK_TFTP=y
CONFIG_NF_CT_NETLINK=y
CONFIG_NETFILTER_TPROXY=y
CONFIG_NETFILTER_XT_TARGET_CLASSIFY=y
CONFIG_NETFILTER_XT_TARGET_CONNMARK=y
CONFIG_NETFILTER_XT_TARGET_MARK=y
CONFIG_NETFILTER_XT_TARGET_NFLOG=y
CONFIG_NETFILTER_XT_TARGET_NFQUEUE=y
CONFIG_NETFILTER_XT_TARGET_TPROXY=y
CONFIG_NETFILTER_XT_TARGET_TRACE=y
CONFIG_NETFILTER_XT_MATCH_COMMENT=y
CONFIG_NETFILTER_XT_MATCH_CONNLIMIT=y
CONFIG_NETFILTER_XT_MATCH_CONNMARK=y
CONFIG_NETFILTER_XT_MATCH_CONNTRACK=y
CONFIG_NETFILTER_XT_MATCH_HASHLIMIT=y
CONFIG_NETFILTER_XT_MATCH_HELPER=y
CONFIG_NETFILTER_XT_MATCH_IPRANGE=y
CONFIG_NETFILTER_XT_MATCH_LENGTH=y
CONFIG_NETFILTER_XT_MATCH_LIMIT=y
CONFIG_NETFILTER_XT_MATCH_MAC=y
CONFIG_NETFILTER_XT_MATCH_MARK=y
CONFIG_NETFILTER_XT_MATCH_POLICY=y
CONFIG_NETFILTER_XT_MATCH_PKTTYPE=y
CONFIG_NETFILTER_XT_MATCH_QTAGUID=y
CONFIG_NETFILTER_XT_MATCH_QUOTA=y
CONFIG_NETFILTER_XT_MATCH_QUOTA2=y
CONFIG_NETFILTER_XT_MATCH_QUOTA2_LOG=y
CONFIG_NETFILTER_XT_MATCH_SOCKET=y
CONFIG_NETFILTER_XT_MATCH_STATE=y
CONFIG_NETFILTER_XT_MATCH_STATISTIC=y
CONFIG_NETFILTER_XT_MATCH_STRING=y
CONFIG_NETFILTER_XT_MATCH_TIME=y
CONFIG_NETFILTER_XT_MATCH_U32=y
CONFIG_NF_CONNTRACK_IPV4=y
CONFIG_IP_NF_IPTABLES=y
CONFIG_IP_NF_MATCH_AH=y
CONFIG_IP_NF_MATCH_ECN=y
CONFIG_IP_NF_MATCH_TTL=y
CONFIG_IP_NF_FILTER=y
CONFIG_IP_NF_TARGET_REJECT=y
CONFIG_IP_NF_TARGET_REJECT_SKERR=y
CONFIG_NF_NAT=y
CONFIG_IP_NF_TARGET_MASQUERADE=y
CONFIG_IP_NF_TARGET_NETMAP=y
CONFIG_IP_NF_TARGET_REDIRECT=y
CONFIG_IP_NF_MANGLE=y
CONFIG_IP_NF_RAW=y
CONFIG_IP_NF_ARPTABLES=y
CONFIG_IP_NF_ARPFILTER=y
CONFIG_IP_NF_ARP_MANGLE=y
CONFIG_NF_CONNTRACK_IPV6=y
CONFIG_IP6_NF_IPTABLES=y
CONFIG_IP6_NF_FILTER=y
CONFIG_IP6_NF_TARGET_REJECT=y
CONFIG_IP6_NF_TARGET_REJECT_SKERR=y
CONFIG_IP6_NF_MANGLE=y
CONFIG_IP6_NF_RAW=y
CONFIG_NET_SCHED=y
CONFIG_NET_SCH_HTB=y
CONFIG_NET_CLS_U32=y
CONFIG_NET_EMATCH=y
CONFIG_NET_EMATCH_U32=y
CONFIG_NET_CLS_ACT=y
CONFIG_NETDEVICES=y
CONFIG_TUN=y
CONFIG_PPP=y
CONFIG_PPP_BSDCOMP=y
CONFIG_PPP_DEFLATE=y
CONFIG_PPP_MPPE=y
CONFIG_PPPOLAC=y
CONFIG_PPPOPNS=y
CONFIG_FB=y
CONFIG_SYNC=y
CONFIG_USB_GADGET=y
CONFIG_USB_G_ANDROID=y
CONFIG_USB_OTG_WAKELOCK=y
CONFIG_SWITCH=y
CONFIG_RTC_CLASS=y
CONFIG_STAGING=y
CONFIG_ANDROID=y
CONFIG_ANDROID_BINDER_IPC=y
CONFIG_ASHMEM=y
CONFIG_ANDROID_LOGGER=y
CONFIG_ANDROID_LOW_MEMORY_KILLER=y
CONFIG_ANDROID_INTF_ALARM_DEV=y
</pre>

<h3 id="recommended">Recommended Configuration</h3>

<pre>
CONFIG_PANIC_TIMEOUT=5
CONFIG_KALLSYMS_ALL=y
CONFIG_PERF_EVENTS=y
CONFIG_COMPACTION=y
# CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
CONFIG_PM_WAKELOCKS_LIMIT=0
# CONFIG_PM_WAKELOCKS_GC is not set
CONFIG_PM_RUNTIME=y
CONFIG_PM_DEBUG=y
CONFIG_SUSPEND_TIME=y
CONFIG_BLK_DEV_LOOP=y
CONFIG_BLK_DEV_RAM=y
CONFIG_BLK_DEV_RAM_SIZE=8192
CONFIG_UID_STAT=y
CONFIG_MD=y
CONFIG_DM_UEVENT=y
CONFIG_INPUT_EVDEV=y
CONFIG_INPUT_KEYRESET=y
# CONFIG_INPUT_MOUSE is not set
CONFIG_INPUT_JOYSTICK=y
CONFIG_JOYSTICK_XPAD=y
CONFIG_JOYSTICK_XPAD_FF=y
CONFIG_JOYSTICK_XPAD_LEDS=y
CONFIG_INPUT_TABLET=y
CONFIG_TABLET_USB_ACECAD=y
CONFIG_TABLET_USB_AIPTEK=y
CONFIG_TABLET_USB_GTCO=y
CONFIG_TABLET_USB_HANWANG=y
CONFIG_TABLET_USB_KBTAB=y
CONFIG_TABLET_USB_WACOM=y
CONFIG_INPUT_MISC=y
CONFIG_INPUT_KEYCHORD=y
CONFIG_INPUT_UINPUT=y
CONFIG_INPUT_GPIO=y
# CONFIG_VT is not set
# CONFIG_LEGACY_PTYS is not set
CONFIG_POWER_SUPPLY=y
CONFIG_BATTERY_ANDROID=y
CONFIG_MEDIA_SUPPORT=y
CONFIG_BACKLIGHT_LCD_SUPPORT=y
CONFIG_SOUND=y
CONFIG_SND=y
CONFIG_UHID=y
CONFIG_USB_HIDDEV=y
CONFIG_HID_A4TECH=y
CONFIG_HID_ACRUX=y
CONFIG_HID_ACRUX_FF=y
CONFIG_HID_APPLE=y
CONFIG_HID_BELKIN=y
CONFIG_HID_CHERRY=y
CONFIG_HID_CHICONY=y
CONFIG_HID_PRODIKEYS=y
CONFIG_HID_CYPRESS=y
CONFIG_HID_DRAGONRISE=y
CONFIG_DRAGONRISE_FF=y
CONFIG_HID_EMS_FF=y
CONFIG_HID_ELECOM=y
CONFIG_HID_EZKEY=y
CONFIG_HID_HOLTEK=y
CONFIG_HID_KEYTOUCH=y
CONFIG_HID_KYE=y
CONFIG_HID_UCLOGIC=y
CONFIG_HID_WALTOP=y
CONFIG_HID_GYRATION=y
CONFIG_HID_TWINHAN=y
CONFIG_HID_KENSINGTON=y
CONFIG_HID_LCPOWER=y
CONFIG_HID_LOGITECH=y
CONFIG_LOGITECH_FF=y
CONFIG_LOGIRUMBLEPAD2_FF=y
CONFIG_LOGIG940_FF=y
CONFIG_HID_MAGICMOUSE=y
CONFIG_HID_MICROSOFT=y
CONFIG_HID_MONTEREY=y
CONFIG_HID_MULTITOUCH=y
CONFIG_HID_NTRIG=y
CONFIG_HID_ORTEK=y
CONFIG_HID_PANTHERLORD=y
CONFIG_PANTHERLORD_FF=y
CONFIG_HID_PETALYNX=y
CONFIG_HID_PICOLCD=y
CONFIG_HID_PRIMAX=y
CONFIG_HID_ROCCAT=y
CONFIG_HID_SAITEK=y
CONFIG_HID_SAMSUNG=y
CONFIG_HID_SONY=y
CONFIG_HID_SPEEDLINK=y
CONFIG_HID_SUNPLUS=y
CONFIG_HID_GREENASIA=y
CONFIG_GREENASIA_FF=y
CONFIG_HID_SMARTJOYPLUS=y
CONFIG_SMARTJOYPLUS_FF=y
CONFIG_HID_TIVO=y
CONFIG_HID_TOPSEED=y
CONFIG_HID_THRUSTMASTER=y
CONFIG_HID_WACOM=y
CONFIG_HID_WIIMOTE=y
CONFIG_HID_ZEROPLUS=y
CONFIG_HID_ZYDACRON=y
CONFIG_USB_USBNET=y
CONFIG_USB_ANNOUNCE_NEW_DEVICES=y
CONFIG_USB_EHCI_HCD=y
CONFIG_ION=y
CONFIG_ANDROID_RAM_CONSOLE=y
CONFIG_ANDROID_TIMED_GPIO=y
CONFIG_EXT4_FS=y
CONFIG_EXT4_FS_SECURITY=y
CONFIG_FUSE_FS=y
CONFIG_MSDOS_FS=y
CONFIG_VFAT_FS=y
CONFIG_TMPFS=y
CONFIG_TMPFS_POSIX_ACL=y
CONFIG_SCHEDSTATS=y
CONFIG_TIMER_STATS=y
CONFIG_SCHED_TRACER=y
CONFIG_CPUSETS=y
CONFIG_PROC_PID_CPUSET=y
</pre>

<h3 id="audio">For USB host mode audio</h3>

<pre>
CONFIG_SND_USB=y
CONFIG_SND_USB_AUDIO=y
# CONFIG_USB_AUDIO is for a peripheral mode (gadget) driver
</pre>

<h3 id="midi">For USB host mode MIDI</h3>

<pre>
CONFIG_SND_USB_MIDI=y
</pre>