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