[U-Boot-Users] Installing U-Boot on target via USB/serial using U-Boot commands
Hello,
I want to find out if U-Boot can be installed on my new target (with no bootloader previously installed) via serial or USB interface using U-Boot commands? I read the U-Boot manual that- if no bootloader is previously installed on the target, a BDM or JTAG interface and can be used. However I want to find out if only U-Boot can be used to install itself over serial or USB interface. Can anyone help here?
(I have disabled HTML but if it still appears, I apologize for that)
Thanks in advance.
Jigisha Goswami
Goswami Jigisha-ejg014 wrote:
Hello,
I want to find out if U-Boot can be installed on my new target (with no bootloader previously installed) via serial or USB interface using U-Boot commands? I read the U-Boot manual that- if no bootloader is previously installed on the target, a BDM or JTAG interface and can be used. However I want to find out if only U-Boot can be used to install itself over serial or USB interface. Can anyone help here?
(I have disabled HTML but if it still appears, I apologize for that)
Thanks in advance.
Jigisha Goswami
No. Flash as it comes from the factory is erased... your CPU would execute a program entirely of 0xFFs, not very interesting.
You need to load a program (e.g. u-boot) into your flash before you can execute u-boot to reload flash.
JTAG allows you to load a program into flash using a special JTAG debug port, typically with the help of the CPU, but the CPU isn't executing instructions in the classic sense.
An option is to preload u-boot into your flash chip via a chip programmer before you put it on the board, but that is a very nasty solution. The best solution is to get a JTAG debugger.
No HTML. Thanks :-). Your line length was rather long, however :-/.
gvb
In message 432F25F1.6070705@smiths-aerospace.com you wrote:
An option is to preload u-boot into your flash chip via a chip programmer before you put it on the board, but that is a very nasty solution. The best solution is to get a JTAG debugger.
I know of a board manufacturer (who shall go unnamed here) who uses the following procedure to (re-) install U-Boot in flash: unsolder the flash chips, re-ball the BGAs, reprogram the chips in a standard flash programmer, re-solder. They think this is cheaper than buying a JTAG debugger... [No smiley here; guess why.]
Best regards,
Wolfgang Denk
In message C4C681B6292E624DB352AC3A74B739500BA31C88@fl08exm03 you wrote:
I want to find out if U-Boot can be installed on my new target (with no bootloader previously installed) via serial or USB interface using U-Boot commands? I read the U-Boot manual that- if no bootloader is previously installed on the target, a BDM or J TAG interface and can be used. However I want to find out if only U-Boot can be used to install itself over serial or USB interface. Can anyone help here?
Ummm.. with no bootloader previously installed? How should this work? You have a chicken and egg type problem. When there is no boot loader then you have to use some sort of flash programmer to transfer the code into flash memory. Something like a JTAG debugger.
(I have disabled HTML but if it still appears, I apologize for that)
No HTML. Good.
Just your line length exceeds the acceptable maximum of some 70 characters.
Best regards,
Wolfgang Denk
participants (3)
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Goswami Jigisha-ejg014 -
Jerry Van Baren -
Wolfgang Denk