After reboot in linux shell, the 'Reset reason' i can get in u-boot is:
1. a POR reset if using imx2_wdt ext_reset(by adding property "fsl,ext-reset-output" to wdog1 node in imx6ul.dtsi) ,which will output a reset signal through WATCHDOG_B, in our hardware design WATCHDOG_B is connet to system POR;
2. a WDOG reset if using imx2_wdt inner_reset default;
The above 2 cases are always true, even the imx watchdog is not started(imx2_wdt_restart).
linux/drivers/watchdog/imx2_wdt.c:
Reset reason print in u-boot:
u-boot/arch/arm/imx-common/cpu.c
If CONFIG_IMX2_WDT in kernel menuconfig is not set, i find that the imx6ull fail to reboot and hang at the end. see below:
My questions:
1. Dose it mean imx6ull soft reboot depend on IMX2_WDT driver?
2. So, which situation can cause 'WARM BOOT' reset reason?
3. And how can i distinguish a soft reset instead of imx watchdog reset?
