On Tuesday 09 March 2004 10:20, you wrote: > Dear David, > sadly I have got no answer to your question, but I want to ask you > something: > Are you using U-Boot for starting Linux? > If you do, can you give me a short roadmap, how to port to new > board?
Yes, we are using u-boot. Well, here's a list of suggestions based on what we did: 1.- Read the README of u-boot. 2.- Assuming there are already other boards with the same CPU and at least a more or less similar setup that are supported, pick one of them, and copy the directory boards/xxxx to boards/yyyy (where yyyy is the name of your board). 3.- Go to include/configs and make a copy of the xxxx.h file. Don't forget to add your board also to the Makefile. 4.- Watch out for special stuff for the board you are using as start, it could get in your way. 5.- Check if the xxxx's config and board support files are indeed a good starting point (clean documented sources, using the newest format of config files and most important, get to fully understand the source). 6.- Look at several other examples to pick up ideas and learn from the sources. 7.- Configure your board with the design information, and from what you learned reading README and the examples. 8.- Leave SDRAM configuration for later (assuming you use a MPC8xx processor, where SDRAM is a special issue), and look if you get something out of your serial port first. 9.- Use Jtag or BDM interfaces to place the bootloader into flash. (We used a homebrewed Jtag interface to program the on-board flash, although everyone and ther brother in this list will probably say that you MUST do it with the BDI2000 from abatron via the BDM port). 10.- Have a Scope at hand to examine the CS and address lines (if at all possible). This may help to see what's going on before the serial port comes into play. 11.- If you have a mpc8xx processor, read the technical notes from Micron about how to interface SDRAM to the MPC8xx, and how to program the UPM correctly. There's a tool from Motorola that let's you draw the waveforms on screen and obtain the corresponding byte-code for the UPM. This might be handy. Again look at and learn from what others did. Good Luck! Best regards, -- David Jander Protonic Holland. tel.: +31 (0) 229 212928 fax.: +31 (0) 229 210930 Factorij 36 / 1628 AL Zwaag ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
