Messages in this thread | | | From | dony <> | Subject | Re: le32_to_cpu() help... | Date | Wed, 3 Nov 1999 02:47:08 +0800 |
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On Tue, 02 Nov 1999, Jes Sorensen wrote: > >>>>> "Dony" == dony <dony.he@huawei.com.cn> writes: > > Dony> On Tue, 02 Nov 1999, Jes Sorensen wrote: > >> They translate data to little endian from big endian on big endian > >> CPUs, on little endian CPUs like the x86 they are noops. We need > >> these because some hardware and other things like file systems > >> wants data in little endian order no matter what type of system you > >> are running on. > > Dony> Then when do we use le32_to_cpu( ) , and when do we use > Dony> cpu_to_le32( )? > > You use le32_to_cpu() when you want to read data which is in little > endian order and you use the other one when you try to write it. > I know this. I just don't know what data is in little endian and what data is in big endian. say the following code ....
struct ext2_super_block * es; struct super_block * sb; .............................. es->smtime=cpu_to_le32(CURRENT_TIME); //why here use cpu_to_le32? sb->u.ext2_sb.s_mount_state=le32_to_cpu(es->state); //why use le32_to_cpu here?
-- #################################### Linux is more powerful than windows dony.he@huawei.com.cn ####################################
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