Hi,
I've got a router with a TNETD7300GDU I'd like to employ, so I begun researching in the subject. This seems to be an AR7 mips32 4KEC cpu, for which no data-sheet is available, and which is apparently running in big-endian mode.
So I cross-compiled a static gcc, and used it to compile the code seen here:
In the section "Hello World!"/barebones to big-endian, as the router's bootloader allows me uploading code to ram I can jump to and execute later.
I also cross-compiled a kernel for this architecture, but no mather what I do, I always get exception messages (cause, epc, etc), though the only that I could infer so far is that whatever I want to execute, seems to be done in kernel mode.
I have previous experience with c, avr, and arm, but definetely mips cores are more complex than what I can get in a couple of days.
The code mentioned above fitted my purposes quite nicely, as I'm using an usb->ttl converter to talk to the router, and so I could use the same to talk back to the host or even make something a bit more interactive that allows me pulling up or down gpio pins to check and better understand the board, find out where the leds are, etc.
So my question is, where should I start from? Appart from not knowing mips, I'm self-taugth, but neither up to a level that I can understand what's really going on at the point I ask the bootloader to execute what I have uploaded (should I set the stack pointer?, initialize the hardware? etc).
So any inputs on the subject would be really appreciated.
Thanks,