common: elf: add elf_open, elf_close and elf_load ...

In order to integrate elf loading into bootm command, split elf opening
from elf loading.

Signed-off-by: Clement Leger <cleger@kalray.eu>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common: elf: load elf directly from file ...

Currently, elf file must be loaded into a buffer and then passed to
elf_load_image. This requires to copy the whole elf file before booting
it. This commit allows to pass the filename directly and will allocate
data only for the elf header (elf header + program headers). This will
then be used to load the elf data from the file without copying it in an
intermediate buffer. Elf segments are first parsed into a list and are
then loaded from the file in a second time.

Signed-off-by: Clement Leger <cleger@kalray.eu>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common: elf: check number of elf program headers ...

An elf file without program headers should not be loaded. Add a check
for such cases.

Signed-off-by: Clement Leger <cleger@kalray.eu>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common: elf: use calloc instead of xzalloc ...

This failure can be handled grecefully, use standard calloc.

Signed-off-by: Clement Leger <cleger@kalray.eu>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common: elf: fix warning on 32 bits architectures ...

When pointers are 32 bits wide and we cast a potentially 64 bits
value in it, the compiler will yield an error. Cast that value first
into a phys_addr_t to match the architecture pointer size and then
in a void *.

Signed-off-by: Clement Leger <cleger@kalray.eu>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common: elf: add computation of elf boundaries ...

In order to correctly load an initrd or a device tree after an elf file,
we need to know its boundaries. This commit adds support for that and
allow the bootm implementations to use it for memory loading.

Signed-off-by: Clement Leger <cleger@kalray.eu>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

elf: add 64 bits elf loading support ...

This patch add elf64 loading support to the elf loader. Since
elf32 and elf64 uses completely different types, to avoid copying all
the code and simply replace elf32 with elf64, use a macro which will
return the appropriate field for each type of header. This macro
generates getter for elf structures according to the class of the loaded
elf.
All direct elf struct dereference are then replaced by call to generated
functions. This allows to keep a common loader code even if types are
different.

Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Clement Leger <cleger@kalray.eu>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

add basic ELF parser ...

This parser is needed for kernel boot support on MIPS
and can potentially reused on other platforms.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>