rPi MMU: Working towards mapped memory

• BCM2708 defines no longer assume 0x20 address We will be throwing away the blob memory mapping and using our own.
• Use existing blob mapping to turn GPIO led on pre mmu_init
• Remap MMU hardware addresses from 0x7E. We could map each device, however the kernel will throw away the mappings again anyway. For now we just map the whole range and use offsets.
• Serial uart no longer works, however at least we know why now :). Serial driver now needs to use mapped address.

rPi MMU: Enhance debugging [2 commits]

• TRACE calls no longer need double '('
• Added CALLED trace function
• Add better debugging output

rPi: MMU Work [2 commits]

• Use U-Boot mmu code as base
• This will be factored out someday into common arch mmu code when we can read Flattened Device Trees
• Move mmu_init after serial_init. Temporary change as we will want serial_init to use memory mapped addresses... for debugging.

rPi: Fix Raspberry Pi binaries

• Since mmu_man fixed these vars to actually be used, we now know these floating point flags cause issues on the Raspberry Pi currently.

Fix passing flags from BoardSetup

• since we include BoardSetup earlier now, the TARGET_* flags were discarded. Use HAIKU_* instead.
• Add variables to hold the default entry point and the desired uimage OS emulation.

U-Boot ppc: Add missing sections to ldscript

• it seems we missed some sections that exist on ppc, add them.
• resulting binary runs a little further in QEMU but still screws up.

U-Boot: save passed FDT and call common code

• should work better this way :D

U-Boot: include board name in uimage header

• for clarity, include the board in the uimage name field, it's long enough.

U-Boot: Fix ppc build [3 commits]

• we have an uimage for the Sam460 \o/

U-Boot: Add a ppc ldscript

• mostly copied from the ARM one

U-Boot: Guard ARM-specific stuff

• those must be cleaned up and moved away
• allows building U-Boot loader for ppc

U-Boot: Add a Linux-type loader target [2 commits]

• those should be cleaned up. BoardSetup should tell which OS type to emulate.

Sam460ex: Add a Linux-type kernel entry point [2 commits]

• the onboard U-Booot and 2nd-stage loader only know a few OS types, we'll try faking Linux there.

uart: Fix arm kernel build

• Make kernel use mmu_man's new UART code
• Remove no longer used uart.cpp / uart.h