On Wed, Jun 18, 2008 at 10:39:30AM -0500, Timur Tabi wrote: > Menon, Nishanth wrote: > > > Please see U-boot v2 here: > > Sorry, I didn't notice that your patch is for U-Boot V2. > > > It does not have i2c support. And IMHO, using kernel like i2c addition in > > U-Boot v2 is appropriate. Why this is not a bloat U-Boot v2? > > If it isn't, then it means that U-Boot V2 will be pretty bloated in general. > > > A) Now, if you just want i2c_transfer without any device interface, you > > don't need to compile in the CHARDEV. > > B) Since we use a different linking strategy in U-Boot-v2 which uses gcc > > link stage to decide which functions be retained and which not, it is > > pretty neat to see all unused functionality disappear. > > C) kernel has additional bus and class types which are useful when we think > > in terms of varied features, in u-boot v2, we don't have a bus and class, > > just a plain device+driver interface like the kernel + ioctls to allow > > "apps" to invoke functionality within the driver for the device. Very linux > > like, call it a micro-linux ;). So kernel i2c architecture fits u_boot v2 > > better that u-boot v1's architecture. > > D) U-boot v2 has insmod + rmmod -> though this is still to be fixed, once > > it is fully functioning, you can loadb just the module feature you need. In > > fact, you could even have a filesystem with just modules.... > > E) Ofcourse, we work in a single threaded, no interrupt mode in u-boot v2+ > > don't care for any power management -> more savings there > > Sounds to me like U-Boot V2 is just a repacked Linux kernel. We could > probably > save ourselves a lot of trouble if we just took the DDR and CPU register > initialization code in U-Boot and moved it to the kernel.
I've thought about going this way... But the Linux Kernel typically has around 1M and still you don't have a shell. U-Boot-v2 is not bigger in code size than V1 with similar functionality. You're right, I took a lot of code (and ideas) from the Linux Kernel, but I'm too unsure if it's a good idea to adopt full-featured frameworks like I2C from the kernel. BTW U-Boot-v1 does the same thing with NAND support for example. Sascha -- Pengutronix e.K. - Linux Solutions for Science and Industry ----------------------------------------------------------- Kontakt-Informationen finden Sie im Header dieser Mail oder auf der Webseite -> http://www.pengutronix.de/impressum/ <- ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ U-Boot-Users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/u-boot-users
