Hi Everyone, I'm trying to get the U-Boot standalone Hello World demo to work on a modified Atmel NGW100 board and I am a bit confused about all the addresses: - examples/Makefile: LOAD_ADDR . Currently set to 0x00000000 for avr32 - mkimage load address (-a) parameter - mkimage entry point (-e) parameter - U-Boot go command address
My ultimate goal (with this little project) is to erase an environment variable and reset the processor. I know this would be very easy with a U-Boot script: http://www.denx.de/wiki/DULG/UBootCmdGroupExec but one of my constraints is that I need to use the fsload + bootm commands to start something that will do just that. I'll resume my understanding of all that I have read and I would really appreciate if someone could correct or complete this. This is a bit long, but I am trying to put all the information in one place so the next person who needs to do the same will have a single source of information. I am using U-Boot 1.3.0.atmel.2 My system's memory is as follows: - Flash 0x00000000 - 0x02000000 (32 MB) - RAM 0x10000000 - 0x14000000 (64 MB) Architecture: avr32 - U-Boot resides in sector 0 of the Flash at address 0x00000000 >From what I understand, when compiling a U-Boot standalone program, one needs to define where the program will be executed since function calls are using absolute addresses. The example/Makefile LOAD_ADDR for the selected architecture should be set to the program's load address. The steps for running a standalone application using the go command in U-Boot are: ==================================================== 1- Compile the standalone Hello World Demo with the "make examples" command from the U-Boot top directory. This step will run the following commands: $ avr32-linux-gcc (compile hello_world.c) $ avr32-linux-ld (link against the linux-uclibc library) . This is also where the start address is defined $ avr32-linux-objcopy (to copy to binary or srec format) 2- Load U-Boot program in memory http://www.denx.de/wiki/DULG/UBootStandalone According to the LOAD_ADDR, the program should be loaded at 0x00000000 (in Flash, over U-Boot). This would overwrite the U-Boot in Flash, already residing in this sector of memory. I would need to load it in RAM. $ tftpboot 0x10300000 hello_world.bin 3- Run using the U-Boot "go" command $ go 0x10300004 This is a test Problem 1: ========== When I change the LOAD_ADDR to 0x10300000, I get a linker error: avr32-linux-ld: hello_world: Not enough room for program headers (allocated 2, need 3) Segment Sections... 00: LOAD: .rela.dyn 01: LOAD: .text .rodata 02: LOAD: .got avr32-linux-ld: final link failed: Bad value (?) Does anyone have an idea what I can do for this? Steps for running a standalone program using bootm: =================================================== Let's assume I was able to run the standalone program usinng the go command. My next step is to create an image that can be started using bootm. 1- Compile the standalone Demo with "make examples" 2- Create an image (.img) using mkimage I assume the address (-a) needs to be the same as the Makefile LOAD_ADDR and the entry point (-e) will be 4 bytes after that. $ mkimage -A avr32 -O u-boot -T standalone -C none \ -a 0x10300000 -e 0x10300004 -n "Hello World" \ -d hello_world.bin hello_world.img 3- Load the image in memory (not the execution place) $ tftpboot 0x11000000 hello_world.img 4- Run the application $ bootm (autostart is set to yes and bootm works when I start linux) (?) Anything wrong in there?
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