1Overview:
2=========
3
4The MPC8536E integrates a PowerPC processor core with system logic
5required for imaging, networking, and communications applications.
6
7Boot from NAND:
8===============
9
10The MPC8536E is capable of booting from NAND flash which uses the image
11u-boot-nand.bin. This image contains two parts: a first stage image(also
12call 4K NAND loader and a second stage image. The former is appended to
13the latter to produce u-boot-nand.bin.
14
15The bootup process can be divided into two stages: the first stage will
16configure the L2SRAM, then copy the second stage image to L2SRAM and jump
17to it. The second stage image is to configure all the hardware and boot up
18to U-Boot command line.
19
20The 4K NAND loader's code comes from the corresponding nand_spl directory,
21along with the code twisted by CONFIG_NAND_SPL. The macro CONFIG_NAND_SPL
22is mainly used to shrink the code size to the 4K size limitation.
23
24The macro CONFIG_SYS_RAMBOOT is used to control the code to produce the
25second stage image. It's set in the board config file when boot from NAND
26is selected.
27
28Build and boot steps
29--------------------
30
311. Building image
32	make MPC8536DS_NAND_config
33	make CROSS_COMPILE=powerpc-none-linux-gnuspe- all
34
352. Change dip-switch
36	SW2[5-8] = 1011
37	SW9[1-3] = 101
38	Note: 1 stands for 'on', 0 stands for 'off'
39
403. Flash image
41	tftp 1000000 u-boot-nand.bin
42	nand erase 0 a0000
43	nand write 1000000 0 a0000
44
45Boot from On-chip ROM:
46======================
47
48The MPC8536E is capable of booting from the on-chip ROM - boot from eSDHC
49and boot from eSPI. When power on, the porcessor excutes the ROM code to
50initialize the eSPI/eSDHC controller, and loads the mian U-Boot image from
51the memory device that interfaced to the controller, such as the SDCard or
52SPI EEPROM, to the target memory, e.g. SDRAM or L2SRAM, then boot from it.
53
54The memory device should contain a specific data structure with control word
55and config word at the fixed address. The config word direct the process how
56to config the memory device, and the control word direct the processor where
57to find the image on the memory device, or where copy the main image to. The
58user can use any method to store the data structure to the memory device, only
59if store it on the assigned address.
60
61Build and boot steps
62--------------------
63
64For boot from eSDHC:
651. Build image
66	make MPC8536DS_SDCARD_config
67	make CROSS_COMPILE=powerpc-none-linux-gnuspe- all
68
692. Change dip-switch
70	SW2[5-8] = 0111
71	SW3[1]   = 0
72	SW8[7]   = 0 - The on-board SD/MMC slot is active
73	SW8[7]   = 1 - The externel SD/MMC slot is active
74
753. Put image to SDCard
76	Put the follwing info at the assigned address on the SDCard:
77
78	   Offset   |   Data     | Description
79	--------------------------------------------------------
80	| 0x40-0x43 | 0x424F4F54 | BOOT signature              |
81	--------------------------------------------------------
82	| 0x48-0x4B | 0x00080000 | u-boot.bin's size           |
83	--------------------------------------------------------
84	| 0x50-0x53 | 0x???????? | u-boot.bin's Addr on SDCard |
85	--------------------------------------------------------
86	| 0x58-0x5B | 0xF8F80000 | Target Address              |
87	-------------------------------------------------------
88	| 0x60-0x63 | 0xF8FFF000 | Execution Starting Address  |
89	--------------------------------------------------------
90	| 0x68-0x6B | 0x6        | Number of Config Addr/Data  |
91	--------------------------------------------------------
92	| 0x80-0x83 | 0xFF720100 | Config Addr 1               |
93	| 0x84-0x87 | 0xF8F80000 | Config Data 1               |
94	--------------------------------------------------------
95	| 0x88-0x8b | 0xFF720e44 | Config Addr 2               |
96	| 0x8c-0x8f | 0x0000000C | Config Data 2               |
97	--------------------------------------------------------
98	| 0x90-0x93 | 0xFF720000 | Config Addr 3               |
99	| 0x94-0x97 | 0x80010000 | Config Data 3               |
100	--------------------------------------------------------
101	| 0x98-0x9b | 0xFF72e40c | Config Addr 4               |
102	| 0x9c-0x9f | 0x00000040 | Config Data 4               |
103	--------------------------------------------------------
104	| 0xa0-0xa3 | 0x40000001 | Config Addr 5               |
105	| 0xa4-0xa7 | 0x00000100 | Config Data 5               |
106	--------------------------------------------------------
107	| 0xa8-0xab | 0x80000001 | Config Addr 6               |
108	| 0xac-0xaf | 0x80000001 | Config Data 6               |
109	--------------------------------------------------------
110	|              ......                                  |
111	--------------------------------------------------------
112	| 0x???????? | u-boot.bin                              |
113	--------------------------------------------------------
114
115	then insert the SDCard to the active slot to boot up.
116
117For boot from eSPI:
1181. Build image
119	make MPC8536DS_SPIFLASH_config
120	make CROSS_COMPILE=powerpc-none-linux-gnuspe- all
121
1222. Change dip-switch
123	SW2[5-8] = 0110
124
1253. Put image to SPI flash
126	Put the info in the above table onto the SPI flash, then
127	boot up.
128