tests/boot_linux_console: Run BusyBox on 5KEc 64-bit cpu

tests/boot_linux_console: Run BusyBox on 5KEc 64-bit cpu

This tests boots a Linux kernel on a Malta machine up to a
busybox shell on the serial console. Few commands are executed
before halting the machine (via reboot).

We use the Fedora 24 kernel extracted from the image at:
https://fedoraproject.org/wiki/Architectures/MIPS
and the initrd cpio image from the kerneltests project:
https://kerneltests.org/

If MIPS is a target being built, "make check-acceptance" will
automatically include this test by the use of the "arch:mips" tags.

Alternatively, this test can be run using:

  $ AVOCADO_ALLOW_UNTRUSTED_CODE=yes \
    avocado --show=console run -t arch:mips64el \
      tests/acceptance/boot_linux_console.py
  console: [    0.000000] Linux version 3.19.3.mtoman.20150408 (mtoman@debian-co3-1) (gcc version 5.0.0 20150316 (Red Hat 5.0.0-0.20) (GCC) ) #3 Wed Apr 8 14:32:50 UTC 2015
  console: [    0.000000] Early serial console at I/O port 0x3f8 (options '38400n8')
  console: [    0.000000] bootconsole [uart0] enabled
  console: [    0.000000] CPU0 revision is: 00018900 (MIPS 5KE)
  console: [    0.000000] Checking for the multiply/shift bug... no.
  console: [    0.000000] Checking for the daddiu bug... no.
  [...]
  console: Boot successful.
  console: cat /proc/cpuinfo
  console: / # cat /proc/cpuinfo
  console: system type            : MIPS Malta
  console: machine                        : Unknown
  console: processor              : 0
  console: cpu model              : MIPS 5KE V0.0
  console: : 1616.89
  console: wait instruction       : nouname -a
  console: microsecond timers     : yes
  console: tlb_entries            : 32
  console: extra interrupt vector : yes
  console: hardware watchpoint    : yes, count: 1, address/irw mask: [0x0ff8]
  console: isa                    : mips1 mips2 mips3 mips4 mips5 mips32r1 mips32r2 mips64r1 mips64r2
  console: ASEs implemented       :
  console: shadow register sets   : 1
  console: kscratch registers     : 0
  console: package                        : 0
  console: core                   : 0
  console: VCED exceptions                : not available
  console: VCEI exceptions                : not available
  console: / #
  console: / # uname -a
  console: Linux buildroot 3.19.3.mtoman.20150408 #3 Wed Apr 8 14:32:50 UTC 2015 mips64 GNU/Linux
  console: reboot
  console: / #
  console: / # reboot
  console: / #
  console: / # reboot: Restarting system
  PASS (7.04 s)
  JOB TIME   : 7.20 s

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20191028073441.6448-27-philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Tested-by: Cleber Rosa <crosa@redhat.com>
Signed-off-by: Cleber Rosa <crosa@redhat.com>