build_kernel_image: Don't use keep_bootcon

I've run into some strange issues with keep_bootcon.  The case in
point is that specifying "earlyprintk=ttyS2,115200n8 console=tty1
keep_bootcon" on an rk3288 board will cause a freeze at bootup due to
the earlyprintk clock being disabled at in inopportune time.  I
believe I've seen some other strange issues in the past as well.

Reading through the kernel parameter docs it sounds like using
keep_bootcon should only be for very special situations.
Specifically, it says:

  Do not unregister boot console at start. This is only useful for
  debugging when something happens in the window between unregistering
  the boot console and initializing the real console.

Let's disable it.  I validated that on snow and peach_pit that the
boot console still looks fine over serial.

TEST=Boards can still see earlyprintk and console over serial.

Change-Id: Idca5085fb9788ddc96234ccdc2ceb1d817cb289e
Signed-off-by: Doug Anderson <>
Reviewed-by: Vadim Bendebury <>
Reviewed-by: Andrew Bresticker <>
Reviewed-by: Aaron Durbin <>
1 file changed