Move the open-coded conversion to a shared function for
use by all architectures.  Change the allocation to prefer
a high address for ARM, as this is required to avoid conflicts
with reserved regions in low memory.  We don't know the specifics
of these regions until after we process the command line and
device tree.
Signed-off-by: NRoy Franz <roy.franz@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Rename relocate_kernel() to efi_relocate_kernel(), and take
parameters rather than x86 specific structure.  Add max_addr
argument as for ARM we have some address constraints that we
need to enforce when relocating the kernel.  Add alloc_size
parameter for use by ARM64 which uses an uncompressed kernel,
and needs to allocate space for BSS.
Signed-off-by: NRoy Franz <roy.franz@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The relocate_kernel() function will be generalized and used
by all architectures, as they all have similar requirements.
Signed-off-by: NRoy Franz <roy.franz@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The efi_high_alloc() and efi_low_alloc() functions
use the EFI_ALLOCATE_ADDRESS option to the EFI
function allocate_pages(), which requires a minimum
of page alignment, and rejects all other requests.
The existing code could fail to allocate depending
on allocation size, as although repeated allocation
attempts were made, none were guaranteed to be page
aligned.
Signed-off-by: NRoy Franz <roy.franz@linaro.org>
Acked-by: NMark Salter <msalter@redhat.com>
Reviewed-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Rename them to be more similar, as low_free() could be used to free
memory allocated by both high_alloc() and low_alloc().
high_alloc() -> efi_high_alloc()
low_alloc()  -> efi_low_alloc()
low_free()   -> efi_free()
Signed-off-by: NRoy Franz <roy.franz@linaro.org>
Acked-by: NMark Salter <msalter@redhat.com>
Reviewed-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Add system table pointer argument to shared EFI stub related functions
so they no longer use a global system table pointer as they did when part
of eboot.c.  For the ARM EFI stub this allows us to avoid global
variables completely and thereby not have to deal with GOT fixups.
Not having the EFI stub fixup its GOT, which is shared with the
decompressor, simplifies the relocating of the zImage to a
bootable address.
Signed-off-by: NRoy Franz <roy.franz@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

No code changes made, just moving functions and #define from x86 arch
directory to common location.  Code is shared using #include, similar
to how decompression code is shared among architectures.
Signed-off-by: NRoy Franz <roy.franz@linaro.org>
Acked-by: NMark Salter <msalter@redhat.com>
Reviewed-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>