On Fri, 5 Oct 2007, Timur Tabi wrote: > Andreas Schwab wrote: > >> The bit mapping on your device is strictly internal to the device and >> has nothing to do with bit order on the C level. > > Then I don't understand that point of defining __LITTLE_ENDIAN_BITFIELD.
What does it mean for a C-level bitfield ordering to be little-endian if the processor is BIG_ENDIAN? > > -- > Timur Tabi > Linux Kernel Developer @ Freescale > - It makes no sense because a bitfield is something having to do with a 'C' compiler and it must NEVER be used as a template to address hardware! 'C' gives no guarantee of the ordering within machine words. The only way you can access them is using 'C'. They don't have addresses like other objects (of course they do exist --somewhere). They are put into "storage units," according to the standard, and these storage units are otherwise undefined although you can align them (don't go there). If you want to call machine-control bits by name, just define them as hexadecimal numbers (unsigned ints) and, if your hardware is for both little/big endian, use a macro that resolves the issue between the number and the hardware. Cheers, Dick Johnson Penguin : Linux version 2.6.16.24 on an i686 machine (5592.59 BogoMips). My book : http://www.AbominableFirebug.com/ _ **************************************************************** The information transmitted in this message is confidential and may be privileged. Any review, retransmission, dissemination, or other use of this information by persons or entities other than the intended recipient is prohibited. If you are not the intended recipient, please notify Analogic Corporation immediately - by replying to this message or by sending an email to [EMAIL PROTECTED] - and destroy all copies of this information, including any attachments, without reading or disclosing them. Thank you. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
