I have a good idea about Agile development process but it seems it does not fit well with a embedded project with significant hardware changes.

I will describe below what we are currently doing (Ad-hoc way, no defined process yet). The changes are divided into three categories and different processes are used for each of them:

1. complete hardware change

   example : use a different video codec IP

   a) Study the new IP

   b) RTL/FPGA simulation

   c) Implement the legacy interface - go to b)

   d) Wait until hardware (tape out) is ready

   f) Test on the real hardware

2. hardware improvement

   example : enhance the image display quality by improving the underlying algorithm

   a) RTL/FPGA simulation

   b) Wait until hardware and test on the hardware

3. Minor change

   example : only change hardware register mapping

   a) Wait until hardware and test on the hardware

The worry is it seems we don't have too much control and confidence about software maturity for the hardware changes as the bring-up schedule is always very tight and the customer desired a seamless change when updating to a new version of hardware.

How did you manage this kind of hardware change? Did you solve that by a Hardware Abstraction Layer (HAL)? Did you have a automatic test for the HAL layer? How did you test when the hardware platform is not even ready? Do you have well-documented processes for this kind of change?