Overview
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--------
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The MPC8544DS system is similar to the 85xx CDS systems such
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as the MPC8548CDS due to the similar E500 core. However, it
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is placed on the same board as the 8641 HPCN system.
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Flash Banks
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-----------
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Like the 85xx CDS systems, the 8544 DS board has two flash banks.
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They are both present on boot, but there locations can be swapped
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using the dip-switch SW10, bit 2.
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However, unlike the CDS systems, but similar to the 8641 HPCN
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board, a runtime reset through the FPGA can also affect a swap
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on the flash bank mappings for the next reset cycle.
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Irrespective of the switch SW10[2], booting is always from the
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boot bank at 0xfff8_0000.
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Memory Map
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----------
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0xff80_0000 - 0xffbf_ffff Alternate bank 4MB
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0xffc0_0000 - 0xffff_ffff Boot bank 4MB
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0xffb8_0000 Alternate image start 512KB
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0xfff8_0000 Boot image start 512KB
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Flashing Images
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---------------
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For example, to place a new image in the alternate flash bank
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and then reset with that new image temporarily, use this:
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tftp 1000000 u-boot.bin.8544ds
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erase ffb80000 ffbfffff
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cp.b 1000000 ffb80000 80000
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pixis_reset altbank
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To overwrite the image in the boot flash bank:
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tftp 1000000 u-boot.bin.8544ds
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protect off all
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erase fff80000 ffffffff
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cp.b 1000000 fff80000 80000
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Other example U-Boot image and flash manipulations examples
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can be found in the README.mpc85xxcds file as well.
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The pixis_reset command
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-----------------------
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A new command, "pixis_reset", is introduced to reset mpc8641hpcn board
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using the FPGA sequencer. When the board restarts, it has the option
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of using either the current or alternate flash bank as the boot
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image, with or without the watchdog timer enabled, and finally with
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or without frequency changes.
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Usage is;
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pixis_reset
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pixis_reset altbank
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pixis_reset altbank wd
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pixis_reset altbank cf <SYSCLK freq> <COREPLL ratio> <MPXPLL ratio>
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pixis_reset cf <SYSCLK freq> <COREPLL ratio> <MPXPLL ratio>
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Examples;
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/* reset to current bank, like "reset" command */
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pixis_reset
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/* reset board but use the to alternate flash bank */
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pixis_reset altbank
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/* reset board, use alternate flash bank with watchdog timer enabled*/
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pixis_reset altbank wd
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/* reset board to alternate bank with frequency changed.
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* 40 is SYSCLK, 2.5 is COREPLL ratio, 10 is MPXPLL ratio
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*/
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pixis-reset altbank cf 40 2.5 10
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Valid clock choices are in the 8641 Reference Manuals.
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Using the Device Tree Source File
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---------------------------------
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To create the DTB (Device Tree Binary) image file,
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use a command similar to this:
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dtc -b 0 -f -I dts -O dtb mpc8544ds.dts > mpc8544ds.dtb
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Likely, that .dts file will come from here;
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linux-2.6/arch/powerpc/boot/dts/mpc8544ds.dts
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After placing the DTB file in your TFTP disk area,
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you can download that dtb file using a command like:
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tftp 900000 mpc8544ds.dtb
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Burn it to flash if you want.
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Booting Linux
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-------------
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Place a linux uImage in the TFTP disk area too.
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tftp 1000000 uImage.8544
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tftp 900000 mpc8544ds.dtb
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bootm 1000000 - 900000
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Watch your ethact, netdev and bootargs U-Boot environment variables.
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You may want to do something like this too:
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setenv ethact eTSEC3
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setenv netdev eth1
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