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https://github.com/AsahiLinux/u-boot
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| ddr.c | ||
| Kconfig | ||
| law.c | ||
| MAINTAINERS | ||
| Makefile | ||
| mpc8536ds.c | ||
| README | ||
| tlb.c | ||
Overview: ========= The MPC8536E integrates a PowerPC processor core with system logic required for imaging, networking, and communications applications. Boot from NAND: =============== The MPC8536E is capable of booting from NAND flash which uses the image u-boot-nand.bin. This image contains two parts: a first stage image(also call 4K NAND loader and a second stage image. The former is appended to the latter to produce u-boot-nand.bin. The bootup process can be divided into two stages: the first stage will configure the L2SRAM, then copy the second stage image to L2SRAM and jump to it. The second stage image is to configure all the hardware and boot up to U-Boot command line. The 4K NAND loader's code comes from the corresponding nand_spl directory, along with the code twisted by CONFIG_NAND_SPL. The macro CONFIG_NAND_SPL is mainly used to shrink the code size to the 4K size limitation. The macro CONFIG_SYS_RAMBOOT is used to control the code to produce the second stage image. It's set in the board config file when boot from NAND is selected. Build and boot steps -------------------- 1. Building image make MPC8536DS_NAND_config make CROSS_COMPILE=powerpc-none-linux-gnuspe- all 2. Change dip-switch SW2[5-8] = 1011 SW9[1-3] = 101 Note: 1 stands for 'on', 0 stands for 'off' 3. Flash image tftp 1000000 u-boot-nand.bin nand erase 0 a0000 nand write 1000000 0 a0000 Boot from On-chip ROM: ====================== The MPC8536E is capable of booting from the on-chip ROM - boot from eSDHC and boot from eSPI. When power on, the porcessor excutes the ROM code to initialize the eSPI/eSDHC controller, and loads the mian U-Boot image from the memory device that interfaced to the controller, such as the SDCard or SPI EEPROM, to the target memory, e.g. SDRAM or L2SRAM, then boot from it. The memory device should contain a specific data structure with control word and config word at the fixed address. The config word direct the process how to config the memory device, and the control word direct the processor where to find the image on the memory device, or where copy the main image to. The user can use any method to store the data structure to the memory device, only if store it on the assigned address. Build and boot steps -------------------- For boot from eSDHC: 1. Build image make MPC8536DS_SDCARD_config make CROSS_COMPILE=powerpc-none-linux-gnuspe- all 2. Change dip-switch SW2[5-8] = 0111 SW3[1] = 0 SW8[7] = 0 - The on-board SD/MMC slot is active SW8[7] = 1 - The externel SD/MMC slot is active 3. Put image to SDCard Put the follwing info at the assigned address on the SDCard: Offset | Data | Description -------------------------------------------------------- | 0x40-0x43 | 0x424F4F54 | BOOT signature | -------------------------------------------------------- | 0x48-0x4B | 0x00080000 | u-boot.bin's size | -------------------------------------------------------- | 0x50-0x53 | 0x???????? | u-boot.bin's Addr on SDCard | -------------------------------------------------------- | 0x58-0x5B | 0xF8F80000 | Target Address | ------------------------------------------------------- | 0x60-0x63 | 0xF8FFF000 | Execution Starting Address | -------------------------------------------------------- | 0x68-0x6B | 0x6 | Number of Config Addr/Data | -------------------------------------------------------- | 0x80-0x83 | 0xFF720100 | Config Addr 1 | | 0x84-0x87 | 0xF8F80000 | Config Data 1 | -------------------------------------------------------- | 0x88-0x8b | 0xFF720e44 | Config Addr 2 | | 0x8c-0x8f | 0x0000000C | Config Data 2 | -------------------------------------------------------- | 0x90-0x93 | 0xFF720000 | Config Addr 3 | | 0x94-0x97 | 0x80010000 | Config Data 3 | -------------------------------------------------------- | 0x98-0x9b | 0xFF72e40c | Config Addr 4 | | 0x9c-0x9f | 0x00000040 | Config Data 4 | -------------------------------------------------------- | 0xa0-0xa3 | 0x40000001 | Config Addr 5 | | 0xa4-0xa7 | 0x00000100 | Config Data 5 | -------------------------------------------------------- | 0xa8-0xab | 0x80000001 | Config Addr 6 | | 0xac-0xaf | 0x80000001 | Config Data 6 | -------------------------------------------------------- | ...... | -------------------------------------------------------- | 0x???????? | u-boot.bin | -------------------------------------------------------- then insert the SDCard to the active slot to boot up. For boot from eSPI: 1. Build image make MPC8536DS_SPIFLASH_config make CROSS_COMPILE=powerpc-none-linux-gnuspe- all 2. Change dip-switch SW2[5-8] = 0110 3. Put image to SPI flash Put the info in the above table onto the SPI flash, then boot up.