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