This change has 3 goals:
- Have secondary cores be released into spin loops at their 'true'
address in SDRAM. Previously, secondary cores were put into spin
loops in the 0xfffffxxx address range which required that boot page
translation was always enabled while cores were in their spin loops.
- Allow the TLB window that the primary core uses to access the
secondary cores boot page to be placed at any address. Previously, a
TLB window at 0xfffff000 was always used to access the seconary cores'
boot page. This TLB address requirement overlapped with other
peripherals on some boards (eg XPedite5370). By default, the boot
page TLB will still use the 0xfffffxxx address range, but this can be
overridden on a board-by-board basis by defining a custom
CONFIG_BPTR_VIRT_ADDR. Note that the TLB used to map the boot page
remains in use while U-Boot executes. Previously it was only
temporarily used, then restored to its initial value.
- Allow Boot Page Translation to be disabled on bootup. Previously,
Boot Page Translation was always left enabled after secondary cores
were brought out of reset. This caused the 0xfffffxxx address range
to somewhat "magically" be translated to an address in SDRAM. Some
boards may not want this oddity in their memory map, so defining
CONFIG_MPC8xxx_DISABLE_BPTR will turn off Boot Page Translation after
the secondary cores are initialized.
These changes are only applicable to 85xx boards with CONFIG_MP defined.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
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