3451556310
the primary serial bootloader (bootloader06) to wait for a specific keypress before running the downloaded program.
48 lines
2.2 KiB
Plaintext
48 lines
2.2 KiB
Plaintext
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See the top level README file for more information on documentation
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and how to run these programs.
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Derived from bootloader05, this is a very simple bootloader. Instead
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of the sd dance (see top level README), this makes life a bit simpler
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and greatly reduces physical wear and tear on the sd card socket. Do
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the sd card dance one more time with this kernel.img. Get some sort of
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serial solution to connect a dumb termial program with xmodem
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capabilities to the uart on the raspberry pi. (see the top level
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README for more information).
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The difference between bootloader05 and bootloader06 is that I made
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it more lean and mean either it works perfect or it bails out, I dont
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know or think the NAK stuff was working anyway. The whole xmodem
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receiver is in a loop so you should be able to try again without
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power cycling the board.
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A new feature is that it does not automatically run your program it
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waits for you to send a 'g' character (press the g button while in
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the dumb terminal program). I use minicom and there is a delay between
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when the external xmodem program finishes sending and when minicom
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gets control again and data can be lost, data as in stuff the
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downloaded program is printing out. So ideally this helps solve that.
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You take the .bin file of your test program, assumed to be built based
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on address 0x8000 and less than 0x200000-0x8000 bytes in size.
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With uart connected to a terminal
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1) power off raspberry pi
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2) power on raspberry pi
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3) use xmodem to transfer binary file
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Repeat for each new program to test
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This bootloader sits at 0x200000 so that you have 0x200000 bytes to
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develop with. And that way if you like your program you can just
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copy a .bin version to kernel.img on the sd card and use it. It
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is easy to change this starting address, see the source for more.
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bootloader01 uses .hex files, bootloader02 through bootloader06 use .bin
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files, .hex files wont work. Consider bootloader01 and 02 to be
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obsolete.
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I normally do not deliver binaries. In this case I have included all
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of the build files so that you can at least get started without having
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to build the bootloader. Backup whatever kernel.img file you are using
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and replace with the kernel.img file in this repo (on your sd card).
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