[Buildroot] uClibc shared library issue

[Robert Smigielski]

Hi everyone

I have been using buildroot 2015.11. and 2010.11 to try to get an old ARM
926EJ-S custom processor (Digi NS-921X) to boot and give me a shell
interface at the one and only serial port console. My issue is that while I
believe the board has booted up on either buildroot version, the behavior
at the serial console is that I can type characters and see them displayed,
the Linux kernel is not responding to the characters. There is no
"buildroot login:" or similar displayed. The serial console simply echos
back the characters I type.

The painful part is this board has only 2 I/O interfaces brought out: a
serial console and a WiFi interface. Thus my only debug and communication
interface is the serial console, and I cannot get it to operate properly.

I have been using the kernel boot args "rdinit=/myinit init=/myinit" to run
my custom init program. I also experimented by using "rdinit=/junk
init=/junk" to verify that loading a non existent program results in the
expected failure to find the file and a kernel panic. That proves that I do
have control of the init program.

I tried experiments such as creating a program myinit.c to simply display
"Hello world" and then sleep.
When I compile the myinit.c into a static executable, I receive the printk
Hello world.
When I compile myinit.c as a shared executable I do not receive the printk
Hello world. I presume that means there is some issue with the uClibc/glibc
shared object loader or shared library.
Now I admit I have no detailed experience with building/testing/debugging
libc issues, shared library loaders, and shared libc. I have much
experience building kernels, uboot, packages, etc for embedded boards.

I need advice and suggestions on what to do next to get myinit.c to run
when compiled against a shared libc. Thanks everyone.

Kind Regards

-- 
Robert Smigielski
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