Kernel with 1PPS support
First take a look how to compile the kernel.
Banana Pi compile kernel and header
I recommend to compile the kernel without modifications in the first step to see if it compiles without any issues. It take much time. In my situation more than 7 hours. But don’t worry a modification goes much faster.
Follow the instructions how to enable 1PPS. (If it’s not already done in your kernel.)
Before you start make a copy of file .config
For example
cp .config .config_original_2017
# make menuconfig .config - Linux/arm 3.4.108 Kernel Configuration ────────────────────────────────────────────────────────────────────────────── ┌──────────────── Linux/arm 3.4.108 Kernel Configuration ─────────────────┐ │ Arrow keys navigate the menu. .Enter. selects submenus --->. │ │ Highlighted letters are hotkeys. Pressing .Y. includes, .N. excludes, │ │ .M. modularizes features. Press .Esc..Esc. to exit, .?. for Help, │ │ for Search. Legend: [*] built-in [ ] excluded .M. module . . │ │ ┌─────────────────────────────────────────────────────────────────────┐ │ │ │ General setup ---> │ │ │ │ [*] Enable loadable module support ---> │ │ │ │ -*- Enable the block layer ---> │ │ │ │ System Type ---> │ │ │ │ [ ] FIQ Mode Serial Debugger │ │ │ │ Bus support ---> │ │ │ │ Kernel Features ---> │ │ │ │ Boot options ---> │ │ │ │ CPU Power Management ---> │ │ │ │ Floating point emulation ---> │ │ │ │ Userspace binary formats ---> │ │ │ │ Power management options ---> │ │ │ │ -*- Networking support ---> │ │ │ │ Device Drivers ---> │ │ │ │ File systems ---> │ │ │ │ Kernel hacking ---> │ │ │ │ Security options ---> │ │ │ │ -*- Cryptographic API ---> │ │ │ │ Library routines ---> │ │ │ │ --- │ │ │ │ Load an Alternate Configuration File │ │ │ │ Save an Alternate Configuration File │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ └─────────────────────────────────────────────────────────────────────┘ │ ├─────────────────────────────────────────────────────────────────────────┤ │ .Select. . Exit . . Help . │ └─────────────────────────────────────────────────────────────────────────┘
Scroll down to the “Device Drivers” section and press the “return” button if the “Select” field is high lighted. Now you see
.config - Linux/arm 3.4.108 Kernel Configuration
──────────────────────────────────────────────────────────────────────────────
┌──────────────────────────── Device Drivers ─────────────────────────────┐
│ Arrow keys navigate the menu. .Enter. selects submenus --->. │
│ Highlighted letters are hotkeys. Pressing .Y. includes, .N. excludes, │
│ .M. modularizes features. Press .Esc..Esc. to exit, .?. for Help, ./. │
│ for Search. Legend: [*] built-in [ ] excluded .M. module . . │
│ ┌─────────────────────────────────────────────────────────────────────┐ │
│ │ Generic Driver Options ---> │ │
│ │ {*} Connector - unified userspace .-. kernelspace linker ---> │ │
│ │ .M. Memory Technology Device (MTD) support ---> │ │
│ │ .M. Parallel port support ---> │ │
│ │ [*] Block devices ---> │ │
│ │ Misc devices ---> │ │
│ │ SCSI device support ---> │ │
│ │ .*. Serial ATA and Parallel ATA drivers ---> │ │
│ │ [*] Multiple devices driver support (RAID and LVM) ---> │ │
│ │ .M. Generic Target Core Mod (TCM) and ConfigFS Infrastructure ->│ │
│ │ [*] Network device support ---> │ │
│ │ [ ] ISDN support ---> │ │
│ │ Input device support ---> │ │
│ │ [*] Gsensor support ---> │ │
│ │ Character devices ---> │ │
│ │ {*} I2C support ---> │ │
│ │ [*] SPI support ---> │ │
│ │ . . HSI support ---> │ │
│ │ PPS support ---> │ │
│ │ PTP clock support ---> │ │
│ │ [*] GPIO Support ---> │ │
│ │ .*. Dallas's 1-wire support ---> │ │
│ │ {*} Power supply class support ---> │ │
│ │ .*. Hardware Monitoring support ---> │ │
│ │ .*. Generic Thermal sysfs driver ---> │ │
│ │ [*] Watchdog Timer Support ---> │ │
│ │ Sonics Silicon Backplane ---> │ │
│ └────v(+)─────────────────────────────────────────────────────────────┘ │
├─────────────────────────────────────────────────────────────────────────┤
│ .Select. . Exit . . Help . │
└─────────────────────────────────────────────────────────────────────────┘
Now go down to “PPS support” and press “return” again.
I selected the following kernel modules with “M”
.config - Linux/arm 3.4.108 Kernel Configuration ────────────────────────────────────────────────────────────────────────────── ┌────────────────────────────── PPS support ──────────────────────────────┐ │ Arrow keys navigate the menu. .Enter. selects submenus --->. │ │ Highlighted letters are hotkeys. Pressing .Y. includes, .N. excludes, │ │ .M. modularizes features. Press .Esc..Esc. to exit, .?. for Help, ./. │ │ for Search. Legend: [*] built-in [ ] excluded .M. module . . │ │ ┌─────────────────────────────────────────────────────────────────────┐ │ │ │ .M. PPS support │ │ │ │ [ ] PPS debugging messages │ │ │ │ [ ] PPS kernel consumer support │ │ │ │ *** PPS clients support *** │ │ │ │ .M. Kernel timer client (Testing client, use for debug) │ │ │ │ .M. PPS line discipline │ │ │ │ .M. Parallel port PPS client │ │ │ │ .M. PPS client using GPIO │ │ │ │ *** PPS generators support *** │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ └─────────────────────────────────────────────────────────────────────┘ │ ├─────────────────────────────────────────────────────────────────────────┤ │ .Select. . Exit . . Help . │ └─────────────────────────────────────────────────────────────────────────┘
Finally save the new configuration. You can verfy the changes with the diff command.
diff .config .config.old
You could build a new kernel. But probably you need also a patch for this driver. It is from Chen Wei weichen302@gmail.com and you can find it here:
https://github.com/infinet/bananapi/blob/master/pps-over-gpio.patch
See also: