Documentation: remove old sbc8260 board specific information

This file contains 8 yr. old board specific information that was for
the now gone ppc implementation, and it pre-dates widespread u-boot
support.  Any of the technical details of the board memory map would be
more appropriately captured in a dts if I revive it as powerpc anyway.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

Documentation/powerpc/00-INDEX

@@ -20,8 +20,6 @@ mpc52xx-device-tree-bindings.txt
 	- MPC5200 Device Tree Bindings
 ppc_htab.txt
 	- info about the Linux/PPC /proc/ppc_htab entry
-SBC8260_memory_mapping.txt
-	- EST SBC8260 board info
 smp.txt
 	- use and state info about Linux/PPC on MP machines
 sound.txt

Documentation/powerpc/SBC8260_memory_mapping.txt

-Please mail me (Jon Diekema, diekema_jon@si.com or diekema@cideas.com)
-if you have questions, comments or corrections.
-
-	* EST SBC8260 Linux memory mapping rules
-
-	http://www.estc.com/ 
-	http://www.estc.com/products/boards/SBC8260-8240_ds.html
-
-	Initial conditions:
-	-------------------
-	
-	Tasks that need to be perform by the boot ROM before control is
-	transferred to zImage (compressed Linux kernel):
-
-	- Define the IMMR to 0xf0000000
-
-	- Initialize the memory controller so that RAM is available at
-	  physical address 0x00000000.  On the SBC8260 is this 16M (64M)
-	  SDRAM.
-
-	- The boot ROM should only clear the RAM that it is using.
-
-	  The reason for doing this is to enhances the chances of a
-	  successful post mortem on a Linux panic.  One of the first
-	  items to examine is the 16k (LOG_BUF_LEN) circular console
-	  buffer called log_buf which is defined in kernel/printk.c.
-
-	- To enhance boot ROM performance, the I-cache can be enabled.
-
-	  Date: Mon, 22 May 2000 14:21:10 -0700
-	  From: Neil Russell <caret@c-side.com>
-
-	  LiMon (LInux MONitor) runs with and starts Linux with MMU
-	  off, I-cache enabled, D-cache disabled.  The I-cache doesn't
-	  need hints from the MMU to work correctly as the D-cache
-	  does.  No D-cache means no special code to handle devices in
-	  the presence of cache (no snooping, etc). The use of the
-	  I-cache means that the monitor can run acceptably fast
-	  directly from ROM, rather than having to copy it to RAM.
-
-	- Build the board information structure (see 
-	  include/asm-ppc/est8260.h for its definition)
-
-	- The compressed Linux kernel (zImage) contains a bootstrap loader 
-	  that is position independent; you can load it into any RAM, 
-	  ROM or FLASH memory address >= 0x00500000 (above 5 MB), or
-	  at its link address of 0x00400000 (4 MB).
-
-	  Note: If zImage is loaded at its link address of 0x00400000 (4 MB),
-	        then zImage will skip the step of moving itself to 
-		its link address.
-
-	- Load R3 with the address of the board information structure
-
-	- Transfer control to zImage
-
-	- The Linux console port is SMC1, and the baud rate is controlled
-	  from the bi_baudrate field of the board information structure.
-	  On thing to keep in mind when picking the baud rate, is that
-	  there is no flow control on the SMC ports.  I would stick
-	  with something safe and standard like 19200.
-
-	  On the EST SBC8260, the SMC1 port is on the COM1 connector of
-	  the board.
-
-	
-	EST SBC8260 defaults:
-	---------------------
-
-                                Chip
-        Memory                  Sel  Bus   Use
-        ---------------------   ---  ---   ----------------------------------
-	0x00000000-0x03FFFFFF   CS2  60x   (16M or 64M)/64M SDRAM
-	0x04000000-0x04FFFFFF   CS4  local  4M/16M SDRAM (soldered to the board)
-	0x21000000-0x21000000   CS7  60x    1B/64K Flash present detect (from the flash SIMM)
-	0x21000001-0x21000001   CS7  60x    1B/64K Switches (read) and LEDs (write)
-	0x22000000-0x2200FFFF   CS5  60x    8K/64K EEPROM
-	0xFC000000-0xFCFFFFFF   CS6  60x    2M/16M flash (8 bits wide, soldered to the board)
-	0xFE000000-0xFFFFFFFF   CS0  60x    4M/16M flash (SIMM)
-
-	Notes:
-	------
-
-	- The chip selects can map 32K blocks and up (powers of 2)
-
-	- The SDRAM machine can handled up to 128Mbytes per chip select
-
-	- Linux uses the 60x bus memory (the SDRAM DIMM) for the 
-	  communications buffers.
-
-	- BATs can map 128K-256Mbytes each.  There are four data BATs and
-	  four instruction BATs.  Generally the data and instruction BATs
-	  are mapped the same.
-
-	- The IMMR must be set above the kernel virtual memory addresses,
-	  which start at 0xC0000000.  Otherwise, the kernel may crash as
-	  soon as you start any threads or processes due to VM collisions 
-	  in the kernel or user process space.
-
-
-	  Details from Dan Malek <dan_malek@mvista.com> on 10/29/1999:
-
-	  The user application virtual space consumes the first 2 Gbytes
-	  (0x00000000 to 0x7FFFFFFF).  The kernel virtual text starts at
-	  0xC0000000, with data following.  There is a "protection hole"
-	  between the end of kernel data and the start of the kernel
-	  dynamically allocated space, but this space is still within
-	  0xCxxxxxxx.
-
-	  Obviously the kernel can't map any physical addresses 1:1 in
-	  these ranges.
-
-
-	  Details from Dan Malek <dan_malek@mvista.com> on 5/19/2000:
-
-	  During the early kernel initialization, the kernel virtual
-	  memory allocator is not operational.  Prior to this KVM
-	  initialization, we choose to map virtual to physical addresses
-	  1:1.  That is, the kernel virtual address exactly matches the
-	  physical address on the bus.  These mappings are typically done
-	  in arch/ppc/kernel/head.S, or arch/ppc/mm/init.c.  Only
-	  absolutely necessary mappings should be done at this time, for
-	  example board control registers or a serial uart.  Normal device
-	  driver initialization should map resources later when necessary.
-
-	  Although platform dependent, and certainly the case for embedded
-	  8xx, traditionally memory is mapped at physical address zero,
-	  and I/O devices above physical address 0x80000000.  The lowest
-	  and highest (above 0xf0000000) I/O addresses are traditionally 
-	  used for devices or registers we need to map during kernel 
-	  initialization and prior to KVM operation.  For this reason, 
-	  and since it followed prior PowerPC platform examples, I chose 
-	  to map the embedded 8xx kernel to the 0xc0000000 virtual address.
-	  This way, we can enable the MMU to map the kernel for proper 
-	  operation, and still map a few windows before the KVM is operational.
-
-	  On some systems, you could possibly run the kernel at the 
-	  0x80000000 or any other virtual address.  It just depends upon 
-	  mapping that must be done prior to KVM operational.  You can never 
-	  map devices or kernel spaces that overlap with the user virtual 
-	  space.  This is why default IMMR mapping used by most BDM tools 
-	  won't work.  They put the IMMR at something like 0x10000000 or 
-	  0x02000000 for example.  You simply can't map these addresses early
-	  in the kernel, and continue proper system operation.
-
-	  The embedded 8xx/82xx kernel is mature enough that all you should 
-	  need to do is map the IMMR someplace at or above 0xf0000000 and it 
-	  should boot far enough to get serial console messages and KGDB 
-	  connected on any platform.  There are lots of other subtle memory 
-	  management design features that you simply don't need to worry 
-	  about.  If you are changing functions related to MMU initialization,
-	  you are likely breaking things that are known to work and are 
-	  heading down a path of disaster and frustration.  Your changes 
-	  should be to make the flexibility of the processor fit Linux, 
-	  not force arbitrary and non-workable memory mappings into Linux.
-
-	- You don't want to change KERNELLOAD or KERNELBASE, otherwise the
-	  virtual memory and MMU code will get confused.
-	
-	  arch/ppc/Makefile:KERNELLOAD = 0xc0000000
-
-	  include/asm-ppc/page.h:#define PAGE_OFFSET    0xc0000000
-	  include/asm-ppc/page.h:#define KERNELBASE     PAGE_OFFSET
-
-	- RAM is at physical address 0x00000000, and gets mapped to 
-	  virtual address 0xC0000000 for the kernel.
-
-
-	Physical addresses used by the Linux kernel:
-	--------------------------------------------
-
-	0x00000000-0x3FFFFFFF   1GB reserved for RAM
-	0xF0000000-0xF001FFFF   128K IMMR  64K used for dual port memory,
-                                 64K for 8260 registers
-
-	
-        Logical addresses used by the Linux kernel:
-	-------------------------------------------
-
-	0xF0000000-0xFFFFFFFF   256M BAT0 (IMMR: dual port RAM, registers)
-	0xE0000000-0xEFFFFFFF   256M BAT1 (I/O space for custom boards)
-	0xC0000000-0xCFFFFFFF   256M BAT2 (RAM)
-	0xD0000000-0xDFFFFFFF   256M BAT3 (if RAM > 256MByte)
-
-
-	EST SBC8260 Linux mapping:
-	--------------------------
-
-	DBAT0, IBAT0, cache inhibited:
-
-                                Chip
-        Memory                  Sel  Use
-        ---------------------   ---  ---------------------------------
-        0xF0000000-0xF001FFFF   n/a  IMMR: dual port RAM, registers
-
-        DBAT1, IBAT1, cache inhibited:
-