This introduces some much overdue chainsawing of the fixed PMB support.
fixed PMB was introduced initially to work around the fact that dynamic
PMB mode was relatively broken, though they were never intended to
converge. The main areas where there are differences are whether the
system is booted in 29-bit mode or 32-bit mode, and whether legacy
mappings are to be preserved. Any system booting in true 32-bit mode will
not care about legacy mappings, so these are roughly decoupled.
Regardless of the entry point, PMB and 32BIT are directly related as far
as the kernel is concerned, so we also switch back to having one select
the other.
With legacy mappings iterated through and applied in the initialization
path it's now possible to finally merge the two implementations and
permit dynamic remapping overtop of remaining entries regardless of
whether boot mappings are crafted by hand or inherited from the boot
loader.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
CONFIG_PMB will eventually allow the MMU to be switched between 29-bit
and 32-bit mode dynamically at runtime.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This has the consequence of changing the section name use for head
code from ".text.head" to ".head.text". Since this commit changes all
users in the architecture, this change should be harmless.
Signed-off-by: Tim Abbott <tabbott@mit.edu>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This enables the same functionality that sh64 has for sh32. When running
on simulated hardware or via remote memory via the debug interface,
memory is gauranteed to be zero on boot already, and skipping the zeroing
of BSS has measurable boot time benefits.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
When using initramfs on systems that don't explicitly clear LOADER_TYPE,
unpack_to_rootfs() tramples tramples the range with the defaults taken
out of .empty_zero_page. This causes kernels with valid initramfs images
to bail out with crc or gzip magic mismatch errors after the second
unpack takes place on certain platform configurations.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Shoves a magic word in to the empty_zero_page section for the
bootloader to work out whether to start the kernel in 29-bit
or 32-bit mode.
[ Renesas CPUs already take care of the initial PMB mappings entirely
in hardware and decide on 29-bit/32-bit physical depending on which
pin powered up the CPU, so this is mostly for ST parts. -- PFM ].
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
