dharanivel wrote: ↑
Wed Jul 03, 2019 4:36 pm
Im studying to develop small os. I need to know how to access ram, wifi, bluetooth etc.
RAM is just addressed, there is no how to access it. Now if you are asking about how to implement protection with the MMU, that is another question.
Are you well enough familiar with the ARM Architecture, its modes of operation, ARM interrupts, the Vector Table, the CP15 registers, the cache architecture, and the ISA? You will not be able to get very much done without that basic information.
WiFi, that is another beast altogether and one that I am not sure why you need for a small OS. If you are in need of an internet connection to a WiFi network, just use Ethernet and a WiFi to Ethernet bridge (like the Vonets VAP11G, or similar), they cost very little.
USB is quite well figured out now. A good starting point would be to study the USPi USB Stack.
Bluetooth is doable I do not remember the details (because I do not use it), though there is a lot of information on these forums about that.
So you do not need Framebuffer? VC-4 anything? Or have you already got that information.