By passing the kernel panic parameter, the system automatically resets after 3 seconds when kernel panic happen example: bootargs  'board=xxxxx console=ttyS0,115200 ubi.mtd=overlay rootfs=/dev/mtdblock:rootfs  rootfstype=squashfs noinitrd init=/sbin/…

DDR工作频率  在600MHZ. include/configs/board953x.h #define CFG_PLL_FREQ            CFG_PLL_650_600_200 #define  CFG_DDR_REFRESH_VAL            0x4138   (default 12c) 0x0100 0001 0011 1000 ./board/atheros/common/init-953x.c:59:#define CFG_DDR2_SCORPION_CAS…

Linux内核启动时需要一些配置信息,如根文件系统的类型.flash分区情况.串口终端的编号.内存的使用情况等等,而由于U-Boot和Linux Kernel的镜像是独立的两个文件,所以只能两者约定好在内存的什么地方存放启动参数,这样U-Boot在启动引导时就将启动参数放置在相应的地址处,而Linux Kernel则去相应的地址读取,然后加以处理. 对于Tiny210开发板,启动参数放置在DDR2 SDRAM起始地址后的0x100偏移处,U-Boot中board/samsung/goni/gon…

uboot commad test test - minimal test like /bin/sh so we can use test command to some judge for example, test –n $uenvcmd    test var uenvcmd length !eq  zero detail learning you  can reference url: https://www.cnblogs.com/tankblog/p/6160808.html Not…

pseudocode: If(reset_button was pressed ) { Change  uboot env bootslot^1 }…

design: when uboot load kerne failed,we can switch to stanbdy system; how to realize: when boot fail, we can let uboot env bootKenrelFailCount++, then save to uboot_env partiton.    watchdog timeout will trigger cpu reset, when bootKernelFailCount bi…

find cpu datasheet , watchdog relate registers: 0x18060008 watchdong timer control 0x1806000c watchdog timer we can read and write watchdog register under uboot console: #mw 0x1806000c 0xffffffff  1 #mw 0x1806000c 0x10000000  1 #mw 0x18060008    0x3 …

reference :https://github.com/lentinj/u-boot/blob/master/doc/README.autoboot how to enable protect sonsole in uboot stage ? we can add follow contest in include/configs/xxxx.h +// add by panzidong for support  protect uboot console +#define CONFIG_AU…

reference: uboot_dir/doc/README.distro Linux distributions are faced with supporting a variety of boot mechanisms,environments or bootloaders (PC BIOS, EFI, U-Boot, Barebox, ...). This makeslife complicated. Worse, bootloaders such as U-Boot have a c…

reference: http://www.denx.de/wiki/DULG/UBootCmdGroupExec => help source source - run script from memory Usage: source [addr] - run script starting at addr - A valid image header must be present => With the source command you can run "shell&quo…