On Sun, Dec 04, 2011 at 10:45:21AM +0100, Heiko Schocher wrote: > This driver implements the Linux kernel half of the boot count feature - > the boot counter can only be reset after it is clear that the > application has been started and is running correctly, which usually > can only be determined by the application code itself. Thus the reset > of the boot counter must be done by application code, which thus needs > an appropriate driver. An appropriate mechanism, not necessarily a driver, see below. > Required feature by the Carrier Grade Linux Requirements Definition; > see for example document "Carrier Grade Linux Requirements Definition > Overview V3.0" at > > http://www.linuxfoundation.org/collaborate/workgroups/cgl/requirements#SMM.6.0_Boot_Cycle_Detection > > Description: OSDL CGL specifies that carrier grade Linux > shall provide support for detecting a repeating reboot cycle > due to recurring failures. This detection should happen in > user space before system services are started. So, technically, a flag would be enough, not necessarily a counter? Although a counter probably has more advantages... > This driver provides read/write access to the U-Boot bootcounter > through PROC FS and/or sysFS file. Why ProcFS? Why ProcFS and/or SysFS? Which has priority? Why not /dev? > The bootcountregister gets configured via DTS. > for example on the enbw_cmc board: > > bootcount@0x23060 { > compatible = "uboot,bootcount"; No. I assume you are not the vendor of what is at 0x23060, the actual device. Only the device must be encoded in the compatible-entry which then implies the bootcount functionality. Also, keep in mind that your solution should be generic for bootloaders. > reg = <0x23060 0x20>; I assume that non-volatile memory would qualify as a boot-counter, so those could be tied to I2C busses etc? reg would not fit then. I do wonder if it makes more sense to add such functionality to the watchdog-core to save the additional device (CCed). Needs a second thought, though... Regards, Wolfram -- Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ |
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