Porting The 2.4 Kernel To 2.6

[turran]

Hi all,
im porting the gp2x 2.4 kernel to the 2.6.18. The system boots but i still have to code all the drivers, currently i only have coded the mtd (nand flash) and the mmc driver (still with errors). The project is registered on google code under the name gp2x_linux26. If someone is interested on helping it would be great, just note that isnt an easy task so ppl with knowledge will be better thanks.

 

[gmiller1018]

The 2.4 kernels are faster and smaller than the 2.6 flavors so you will have less memory for your apps. That being said, are you using the ELDK tools? I started to look into this but decided I could not attempt this on my own since I knew very little about the internals of the GP2X. I do have a NEUROS based embedded machine that is running a 2.6 kernel.

I have a big project to finish, but it should be done in a week so I can gt back to working on the GP2X. If that time frame is OK then I would be willing to help.

 

[J201605]

what are the advantages of the 2.6 kernal... would this mean more drivers like sdio etc.?

 

[gmiller1018]

In genral the 2.6 kernel has better support for USB devices (support for IEEE80211 was broken out) and a bunch of other changes that helped make some drivers more maintainable. But in doing so some things got bigger so the memory foot print of the OS is larger.

URL: http://www.denx.de/wiki/Know/Linux24vs26?s...able=4&up=0

Using the 2.6 kernel on embedded systems implicates the following disadvantages:

* Slow to build: 2.6 takes 30...40% longer to compile
* Big memory footprint in flash: the 2.6 compressed kernel image is 30...40% bigger
* Big memory footprint in RAM: the 2.6 kernel needs 30...40% more RAM; the available RAM size for applications is 700kB smaller
* Slow to boot: 2.6 takes 5...15% longer to boot into multi-user mode
* Slow to run: context switches up to 96% slower, local communication latencies up to 80% slower, file system latencies up to 76% slower, local communication bandwidth less than 50% in some cases.

There may be a few cases where the use of Linux kernel version 2.6 makes sense even for embedded systems (typically on "bigger" systems with more powerful processors), but if memory footprint or system performance are important you probably want to stick with a 2.4 kernel for now.

-- WolfgangDenk - 24 Apr 2005

 

[turran]

The 2.4 kernels are faster and smaller than the 2.6 flavors so you will have less memory for your apps.

Well, the truth is i havent compared the 2.6 kernel against a 2.4. As you quoted, there are some info about it, but for the gp2x what we need is fast/full-featured drivers, the system calls implementations, fs, etc is out of topic imho.

That being said, are you using the ELDK tools? I started to look into this but decided I could not attempt this on my own since I knew very little about the internals of the GP2X. I do have a NEUROS based embedded machine that is running a 2.6 kernel.

No, im not using the ELDK tools.

I have a big project to finish, but it should be done in a week so I can gt back to working on the GP2X. If that time frame is OK then I would be willing to help.

Would be nice, i hope there's more people on this board willing to join