move boards to arch/<architecure>/boards ...

this will allow each arch to handle the boards more simply and depending on
there need

the env var BOARD will refer to the current board dirent

for sandbox as we have only one board the board dirent is arch/sandbox/board

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

make reset_cpu a __noreturn function ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add the whole x86 architecture to the build system ...

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add a special command to load and start a bzImage on x86 ...

Other architectures are supporting the uImage format used by barebox's 'bootm'
command. x86 does'nt. So, we need a special command to be able to boot the
x86 specific bzImage format.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add a low level disk drive access driver ...

This is a low level disk drive communication driver. It uses the real mode
BIOS found on most x86 platforms, to read and write sectors. Used by the
generic disk driver.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Bring in the time reference for the x86 platforms ...

This code uses the always (hopefully) existing PIT device to get the time
reference for barebox.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add a generic PC platform ...

This code adds a generic x86 platform, enabling barebox to act as a
bootloader like 'GRUB'. Very minimalistic, yet. Supports only a serial console
and is tested with QEMU only.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add functions to be able to boot with BIOSs help ...

These functions are special: They are running in the 16 bit real mode world
to bring up barebox on an x86 box.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add some generic functions to make x86 work ...

Add some generic functions to make barebox work on x86.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Bring in the first x86 specific code ...

Add some generic required code to make barebox work on x86.
Note: Resetting the CPU is unfinished yet. I need some ideas how to reset
this kind of architecture gracefully.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Adding required architecture header files ...

Add architecture header files. Some of these files are empty, they only must
exists to make the build system happy.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Adding x86 usage documentation to the tree ...

Adding x86 usage documentation to the tree

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>