devmem2

http://free-electrons.com/pub/mirror/devmem2.c, by Jan-Derk Bakker

Very useful tool to directly peek (read) or poke (write) I/O addresses mapped in physical address space from a shell command line!

• Very useful for early interaction experiments with a device, without having to code and compile a driver.

• Uses mmap to /dev/mem.

• Examples (b: byte, h: half, w: word) devmem2 0x000c0004 h (reading) devmem2 0x000c0008 w 0xffffffff (writing)

• devmem is now available in BusyBox, making it even easier to use.