Hello,
I'm trying to use AT91SAM9G25-EK board for machine learning. One of the reasons I chose this board, besides it targeting ARM9 which was my focus, is that is has 1GB of RAM.
I've used the following guide to setup a Debian installation: https://eewiki.net/display/linuxonarm/AT91SAM9x5
The gist of it is, I'm using AT91Bootstrap as a first stage bootloader and u-boot as a second stage.
I'm compiling from github (branch v2016.07-rc2) and patching it with the following: https://rcn-ee.com/repos/git/u-boot-patches/v2016.07-rc2/0001-at91sam9x5ek-u...
Everything works well, but linux cannot see more than 128MB of the memory.
I'm (almost) a complete noob when it comes to embedded programming, but what I understood so far is that u-boot defines the memory layout in the configuration files. Sure enough, I found the definitions that limit the memory being used: https://github.com/u-boot/u-boot/blob/master/include/configs/at91sam9x5ek.h
Could I please get some help adjusting it in order to use all available memory? I tried changing CONFIG_SYS_SDRAM_SIZE to 512MB (0x20000000) and it won't boot. Also changing "fdtaddr" (which I have no idea what it does) in CONFIG_EXTRA_ENV_SETTINGS to "fdtaddr=0x39FF0000" yields the same result.
For the moment I lack a RS232 port on my dev machine, so I can't give you more insight into what fails. But I'm obviously doing something horribly wrong here, so if you could give me some tips or point me to some relevant documentation, I would be grateful.
Thank you! Vasile Vilvoiu