45 lines
1.6 KiB
Plaintext
45 lines
1.6 KiB
Plaintext
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See the top level README for information on where to find documentation
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for the raspberry pi and the ARM processor inside. Also find information
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on how to load and run these programs.
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This example is for the pi2, see other directories for other flavors
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of raspberry pi.
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Normally I prefer to not use a config.txt. The standard boot files
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bootcode.bin, start.elf, and kernel7.img are how most of the raspberry
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pis in the world are used, booting linux. Well tested. config.txt
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creates exceptions to that, and from the early days of the raspi to
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the present some of these have come and gone.
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After messing with aarch64 on the pi3, I am slightly starting to warm
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to the idea of using a config.txt. At least some of the time. Have
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to for now for the pi3 to stay in aarch64 mode. For the pi2 we can
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somewhat return the pi3 to SVC mode from HYP mode.
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See the uart01 example, I agree with the folks online.
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The MPIDR for the four cores are
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80000F00
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80000F01
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80000F02
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80000F03
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Which makes it pretty easy to separate the four cores execution paths.
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For these SVC_BOOT examples you will need a config.txt file in the
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same directory as kernel7.img containing
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kernel_old=1
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disable_commandline_tags=1
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The first line says please load kernel7.img to address 0x0000 instead
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of 0x8000. The second line says please dont trash the first few hundred
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bytes of memory with ATAG nor device tree information.
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If you want to go back to using other examples not in the SVC_BOOT
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directory you need to delete or rename the config.txt file they will
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not work in general, maybe you get lucky but eventually that luck runs
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out.
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