#
# Copyright 2014 Freescale Semiconductor
#
# SPDX-License-Identifier:      GPL-2.0+
#

Freescale LayerScape with Chassis Generation 3

This architecture supports Freescale ARMv8 SoCs with Chassis generation 3,
for example LS2085A.

DDR Layout
============
Entire DDR region splits into two regions.
 - Region 1 is at address 0x8000_0000 to 0xffff_ffff.
 - Region 2 is at 0x80_8000_0000 to the top of total memory,
   for example 16GB, 0x83_ffff_ffff.

All DDR memory is marked as cache-enabled.

When MC and Debug server is enabled, they carve 512MB away from the high
end of DDR. For example, if the total DDR is 16GB, it shrinks to 15.5GB
with MC and Debug server enabled. Linux only sees 15.5GB.

The reserved 512MB layout looks like

   +---------------+ <-- top/end of memory
   |    256MB      |  debug server
   +---------------+
   |    256MB      |  MC
   +---------------+
   |     ...       |

MC requires the memory to be aligned with 512MB, so even debug server is
not enabled, 512MB is reserved, not 256MB.

Flash Layout
============

(1) A typical layout of various images (including Linux and other firmware images)
   is shown below considering a 32MB NOR flash device present on most
   pre-silicon platforms (simulator and emulator):

	-------------------------
	| 	FIT Image	|
	| (linux + DTB + RFS)	|
	------------------------- ----> 0x0120_0000
	| 	Debug Server FW |
	------------------------- ----> 0x00C0_0000
	|	AIOP FW 	|
	------------------------- ----> 0x0070_0000
	|	MC FW 		|
	------------------------- ----> 0x006C_0000
	| 	MC DPL Blob 	|
	------------------------- ----> 0x0020_0000
	| 	BootLoader + Env|
	------------------------- ----> 0x0000_1000
	|	PBI 		|
	------------------------- ----> 0x0000_0080
	|	RCW 		|
	------------------------- ----> 0x0000_0000

	32-MB NOR flash layout for pre-silicon platforms (simulator and emulator)

(2) A typical layout of various images (including Linux and other firmware images)
    is shown below considering a 128MB NOR flash device present on QDS and RDB
    boards:
	----------------------------------------- ----> 0x5_8800_0000 ---
	|	.. Unused .. (7M)		|			|
	----------------------------------------- ----> 0x5_8790_0000	|
	| FIT Image (linux + DTB + RFS)	(40M)	|			|
	----------------------------------------- ----> 0x5_8510_0000	|
	|	PHY firmware (2M)	 	|			|
	----------------------------------------- ----> 0x5_84F0_0000	| 64K
	|	Debug Server FW (2M)		|			| Alt
	----------------------------------------- ----> 0x5_84D0_0000	| Bank
	|	AIOP FW (4M)			|			|
	----------------------------------------- ----> 0x5_8490_0000 (vbank4)
	|	MC DPC Blob (1M) 		|			|
	----------------------------------------- ----> 0x5_8480_0000	|
	|	MC DPL Blob (1M)		|			|
	----------------------------------------- ----> 0x5_8470_0000	|
	| 	MC FW (4M)			|			|
	----------------------------------------- ----> 0x5_8430_0000	|
	|	BootLoader Environment (1M) 	|			|
	----------------------------------------- ----> 0x5_8420_0000	|
	|	BootLoader (1M)			|			|
	----------------------------------------- ----> 0x5_8410_0000	|
	|	RCW and PBI (1M) 		|			|
	----------------------------------------- ----> 0x5_8400_0000 ---
	|	.. Unused .. (7M)		|			|
	----------------------------------------- ----> 0x5_8390_0000	|
	| FIT Image (linux + DTB + RFS)	(40M)	|			|
	----------------------------------------- ----> 0x5_8110_0000	|
	|	PHY firmware (2M)	 	|			|
	----------------------------------------- ----> 0x5_80F0_0000	| 64K
	|	Debug Server FW (2M)		|			| Bank
	----------------------------------------- ----> 0x5_80D0_0000	|
	|	AIOP FW (4M)			|			|
	----------------------------------------- ----> 0x5_8090_0000 (vbank0)
	|	MC DPC Blob (1M) 		|			|
	----------------------------------------- ----> 0x5_8080_0000	|
	|	MC DPL Blob (1M)		|			|
	----------------------------------------- ----> 0x5_8070_0000	|
	| 	MC FW (4M)			|			|
	----------------------------------------- ----> 0x5_8030_0000	|
	|	BootLoader Environment (1M) 	|			|
	----------------------------------------- ----> 0x5_8020_0000	|
	|	BootLoader (1M)			|			|
	----------------------------------------- ----> 0x5_8010_0000	|
	|	RCW and PBI (1M) 		|			|
	----------------------------------------- ----> 0x5_8000_0000 ---

	128-MB NOR flash layout for QDS and RDB boards

Environment Variables
=====================
mcboottimeout:	MC boot timeout in milliseconds. If this variable is not defined
		the value CONFIG_SYS_LS_MC_BOOT_TIMEOUT_MS will be assumed.

mcmemsize:	MC DRAM block size. If this variable is not defined, the value
		CONFIG_SYS_LS_MC_DRAM_BLOCK_MIN_SIZE will be assumed.

Booting from NAND
-------------------
Booting from NAND requires two images, RCW and u-boot-with-spl.bin.
The difference between NAND boot RCW image and NOR boot image is the PBI
command sequence. Below is one example for PBI commands for QDS which uses
NAND device with 2KB/page, block size 128KB.

1) CCSR 4-byte write to 0x00e00404, data=0x00000000
2) CCSR 4-byte write to 0x00e00400, data=0x1800a000
The above two commands set bootloc register to 0x00000000_1800a000 where
the u-boot code will be running in OCRAM.

3) Block Copy: SRC=0x0107, SRC_ADDR=0x00020000, DEST_ADDR=0x1800a000,
BLOCK_SIZE=0x00014000
This command copies u-boot image from NAND device into OCRAM. The values need
to adjust accordingly.

SRC		should match the cfg_rcw_src, the reset config pins. It depends
		on the NAND device. See reference manual for cfg_rcw_src.
SRC_ADDR	is the offset of u-boot-with-spl.bin image in NAND device. In
		the example above, 128KB. For easy maintenance, we put it at
		the beginning of next block from RCW.
DEST_ADDR	is fixed at 0x1800a000, matching bootloc set above.
BLOCK_SIZE	is the size to be copied by PBI.

RCW image should be written to the beginning of NAND device. Example of using
u-boot command

nand write <rcw image in memory> 0 <size of rcw image>

To form the NAND image, build u-boot with NAND config, for example,
ls2085aqds_nand_defconfig. The image needed is u-boot-with-spl.bin.
The u-boot image should be written to match SRC_ADDR, in above example 0x20000.

nand write <u-boot image in memory> 200000 <size of u-boot image>

With these two images in NAND device, the board can boot from NAND.

Another example for RDB boards,

1) CCSR 4-byte write to 0x00e00404, data=0x00000000
2) CCSR 4-byte write to 0x00e00400, data=0x1800a000
3) Block Copy: SRC=0x0119, SRC_ADDR=0x00080000, DEST_ADDR=0x1800a000,
BLOCK_SIZE=0x00014000

nand write <rcw image in memory> 0 <size of rcw image>
nand write <u-boot image in memory> 80000 <size of u-boot image>

Notice the difference from QDS is SRC, SRC_ADDR and the offset of u-boot image
to match board NAND device with 4KB/page, block size 512KB.
