oh, thank's for all guys :) what is privilege ring of CPU (0 and 3) can you give a detil about that ??
may i know where is the place to find some guide or reference about user space and kernel space On Thu, Sep 16, 2010 at 6:32 PM, arshad hussain <[email protected]>wrote: > On 9/16/2010 11:56 AM, jhoni maux wrote: > >> HI, >> >> Now i'm learn kernel module programming, but i'm still confuse about >> user space context and kernel space context. >> > > Here I think 'user space context' and 'user space' implies > the same thing. > > > > anyone know about what > >> the different between user space and kernel space and how to see the >> underlaying between user space and kernel space ?? >> > > So... > > In 'Kernel space' the running program can access all the > CPU instruction set. While in user space the programs > has access to limited CPU instruction. This is accomplished > through setting proper privilege bits in the Segment selector > and Descriptors. For example 'user space' program cannot issue > cli instruction... > > CPU designers also call 'kernel space' as Ring0. while > 'user space' is known as Ring3. > > Thanks > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to [email protected] > Please read the FAQ at http://kernelnewbies.org/FAQ > >
