I am new to this forum and at first of all I want to thank you for maintaining this.
I am newcomer to ARM and uCLinux. I was using 8051 for 15 years. Due need of LAN I jumped a year ago to embedded DOS on x86 based boards. Easy and fast development with known tools. But I need multitasking and therefore I was looking for a new standard platform, as 8051 was in the past, and found the ARM and Linux. First I looked to Cirrus EP9302 (very powerful) and then I found the LPC2468, just what I need.
Looking for development board I found the Olimex LPC-E2468. It just fulfills my needs and could be my election. But I have just some questions because it has no external NOR Flash:
¿Does uCLinux fit into the internal Flash? If so, ¿how much space remains free and what utilities does it have (telnet, ftp, …)?
If not, ¿is there a good way to have separate data and program spaces? ¿Isn’t NAND a bit risky for code?
If so, ¿how much space remains free and what utilities does it have (telnet, ftp, …)?
Even if you manage to build a kernel that fits into 512kB, you still don’t have space for tools.
Olimex ships a distribution with this board. So I’m asking where is the whole operating system stored because I think the LPC2468 won’t boot from NAND flash, does it? It could be that only kernel image and bootloader are stored on internal flash. All other tools and programs could be on NAND. Other alternatives use a 4MB NOR flash and a bigger NAND flash. Now, if everything fits on NOR, could there be space enough for my little application? That’s the question.
denial:
If not, ¿is there a good way to have separate data and program spaces?
I guess you can create maps for the MTD driver to partition the NAND flash.
Hmm, interesting possibility. Will have to learn how-to.
denial:
¿Isn’t NAND a bit risky for code?
Why? You verify the code once it has been written and don’t modify the pages afterwards.
I mean in hardware terms. I have read that NOR is much more resistant as NAND when electrical noise, EM, etc…
Cutanda, here is my opinion of NOR/NAND matters. I would recommend to have “bootloader” (very vague and general term) to handle NOR/NAND storage space management issues. U-Boot is one of featured bootloaders available free in that SW domain. Had U-Boot in small NOR, other part of storage is easily managed, including booting kernel image itself and “memory resident filesystem (aka initrd)” or other filesys to use. Porting U-Boot is not easy task particularily for new comers to 32bit RISC SW domain, however, it would get paid off later. A part of the reason is porting bootloaders is the very good way to learn the target HW. There is literaly tons of examples about how to boot off the bare metal HWs. My 0.02 cent of how to learn RISC programming.