[RFC 0/1] am335x kernel not booting

Stefan Müller-Klieser s.mueller-klieser at phytec.de
Wed Jun 22 07:49:03 PDT 2016

Dear list,

this is more of a request for help, as I am not sure if my current
analysis is correct. The problem I am having is that the kernel current
master does not boot and fails with:

Error: unrecognized/unsupported machine ID (r1 = 0x00001030).

My setup is:
kernel: master with multiv7/omap2plus defconfig
barebox: master with phycore-am335x image

Git bisecting lead to the DEBUG_RODATA change, which is now turned on
for arm and arm64. Google brought up this thread:


Which brought me to the bootm.c in barebox to check if there is enough
space for decompression. I found the assumption of a compression factor
of 4 also in the barebox. What puzzles me is that this assumption still
holds true even for DEBUG_RODATA, at least for my case, though.
With DEBUG_RODATA turned on, the compression ratio went up from 2.9 to
3.5. So my guess is that the kernel is relocating and barebox does not
account for this case. Additionally I found some recommendations in
git/kernel/Documentation/arm/Booting which I think should be taken
into consideration for barebox.
With the attached patch, everything works fine (tested on one single
board 256MiB RAM only).

So, if anyone has more information, I am happy to learn.

Yours, Stefan

Stefan Müller-Klieser (1):
  ARM: bootm: recalculate decompression space

 arch/arm/lib/bootm.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)


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