
Bringup is Hard [pdf] - beefhash
http://www.garbled.net/tmp/bringup.pdf
======
jnwatson
My primary job for almost 2 years was bringing up boards. It is at the same
time immensely challenging and absolutely unappreciated.

As an example of the challenge, My first task in the job was to port a ROM
monitor to a custom StrongARM board. StrongARM had JTAG, but no run control,
therefore, I could load and run code, but could not stop it or look at memory.

At first, I could only observe (with my eyes) when the board resets. Soon, I
could toggle 4 LEDs on the board. That was enough for me to debug by streaming
values one nybble at a time. Soon after, I could emit characters from the
serial port.

That was the good old days.

~~~
djcapelis
Heh. For me, I used an IR thermometer to figure out when the board was running
and when it quiesced. Thankfully most of the work was already done and I just
needed to put some pieces together so I got a console shortly afterward. Then
it was the normal development work of getting a more current kernel version
running, etc.

------
mrlyc
One thing to watch out for is when the board manufacturer changes its memory
map without telling you. Boards built before April booted and the new ones
didn't. Fortunately, the product was still in the development stage.

