From: Ventura <[email protected]> Reply-To: "[email protected]" <[email protected]> Date: Saturday, August 2, 2014 at 9:20 PM To: "[email protected]" <[email protected]> Subject: [beagleboard] Beaglebone bare metal code
> I have an small code just to blink user leds loaded at address 0x80000000. > When I use the bootloader from StarterWare it works perfectly but when I try > to load using JTAG in the same address, I get an error that I suppose it's > something related with memory protection. > > In the past I had the same problem using uBoot when I try to execute Linux in > single step. The work around was enable ICACHE using an uBoot function and the > kernel loaded with no problem. > > At this time I have no loader, just the JTAG interface and I have the same > problem. Enabling ICACHE doesn't fix the problem and I still have no chance to > execute at 0x80000000. I can succeed loading the program at 0x40300000 where > the MMU has no access (I guess!). > >> background polling: on >> TAP: am335x.dap (enabled) >> target state: halted >> target halted in ARM state due to debug-request, current mode: Supervisor >> cpsr: 0xa0000193 pc: 0x00026e1c >> MMU: disabled, D-Cache: disabled, I-Cache: enabled >> JTAG-DP STICKY ERROR >> MEM_AP_CSW 0x2800062, MEM_AP_TAR 0x80000000 >> Failed to write memory at 0x80000000 >> JTAG-DP STICKY ERROR >> MEM_AP_CSW 0x2800062, MEM_AP_TAR 0x800000b4 >> Failed to write memory at 0x800000b4 > > Anybody knows how should be the initial configuration to use the address > 0x80000000-0xA0000000 ??? > > I am sure that there is something that I do not understand about memory/cache > initialization. Code Composer Studio will have GEL files that setup and initialize memory/cache so you can download code and debug. GEL files are easy to read so I suggest you download CCSV6 eval and look for the GEL files for AM335x. Everything you need will be in these GEL files. My guess is you need to initialize DDR3 (memory map, timing, etc) before you are able to download code. Normally, u-boot does this for you. Regards, John > > > > Ventura > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
