Re: unistd.h and 'extern's and 'syscall' "standard(?)"

[Andreas Schwab]

LA Walsh <[e-mail]> writes:

|>         I have a question.  Some architectures have "system calls"
|> implemented as library calls (calls that are "system calls" on ia32)
|> For example, the expectation on 'arm', seems to be that sys_sync
|> is in a library.  On alpha, sys_open appears to be in a library.
|> Is this correct?
|> 
|>         Is it the expectation that the library that handles this
|> is the 'glibc' for that platform or is there a special "kernel.lib"
|> that goes with each platform?
|> 
|> 	Is there 1 library that I need to link my apps with to
|> get the 'externs' referenced in "unistd.h"?
|> 
|> 	The reason I ask is that in ia64 the 'syscall' call
|> isn't done with inline assembler but is itself an 'extern' call.
|> This implies that you can't do system calls directly w/o some 
|> support library.

Don't use kernel headers in user programs.  Just use syscall(3).

Andreas.

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