Change in coreboot[master]: lib/thread: Verify threads are initialized before yielding

[Raul Rangel (Code Review)]

Attention is currently required from: Raul Rangel.
Hello build bot (Jenkins), Furquan Shaikh, Julius Werner, Karthik Ramasubramanian,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/56318

to look at the new patch set (#2).

Change subject: lib/thread: Verify threads are initialized before yielding
......................................................................

lib/thread: Verify threads are initialized before yielding

In hardwaremain.c we call console_init before threads_initialize. Part
of setting up the uart requires calling udelay which then calls
thread_yield_microseconds. Since threads have not been set up, trying to
yield will result in bad things happening. This change guards the thread
methods by making current_thread return NULL if the structures have not
been initialized.

BUG=b:179699789
TEST=Ramstage no longer hangs with serial enabled

Signed-off-by: Raul E Rangel 
Change-Id: If9e1eedfaebe584901d2937c8aa24e158706fa43
---
M src/lib/thread.c
1 file changed, 7 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/18/56318/2