[bootlin/training-materials] ea17e4: embedded-linux: on stm32, don't load kernel right ...

[Michael Opdenacker]

  Branch: refs/heads/master
  Home:   https://github.com/bootlin/training-materials
  Commit: ea17e44ee872123092400052e53999bcf2411fd4
      https://github.com/bootlin/training-materials/commit/ea17e44ee872123092400052e53999bcf2411fd4
  Author: Michael Opdenacker <michael.opdenacker at bootlin.com>
  Date:   2023-02-17 (Fri, 17 Feb 2023)

  Changed paths:
    M common/embedded-linux-labs-vars.tex

  Log Message:
  -----------
  embedded-linux: on stm32, don't load kernel right at start of RAM

That's not recommended practise, as the compressed kernel would
overlap with the uncompressed kernel, as explained on
https://people.kernel.org/linusw/how-the-arm32-linux-kernel-decompresses

As a consequence, the kernel bootstrap code has to make a copy of the
compressed kernel far enough in RAM so there is no such overlap.

Tests on stm32mp157a-dk1 show a 107 ms boot time reduction
(observed consistently on 2 series of 5 tests).

Signed-off-by: Michael Opdenacker <michael.opdenacker at bootlin.com>