Re: Subject: [9fans] Subject: How Subject: do Subject: 9syscalls Subject: work?

Re: Subject: [9fans] Subject: How Subject: do Subject: 9syscalls Subject: work?

[gdiaz]

Hola,

could it be that some of those syscalls are the non-portable version optimized for a specific platform?

slds.

gabi


-- anant@kix.in wrote: 
>
>Hi,
>
>Sorry if this is explained somewhere already. I couldn't find an 
>answer, so here we go.
>
>Considering the `print' function of libc, we see that it calls 
>`vfprint', which in turn calls `fmtFdFlush', which finally calls 
>`write' with 3 parameters.
>
>write(2) says that the source is to be found in /sys/src/libc/ 
>9syscall, but the mkfile in there defines `_write' which in turn does 
>nothing but push the value 20 on the accumulator and call the 
>interrupt 0x64.
>
>a) Where is `write' actually defined? (Or does `write' simply call 
>`_write'?)
>b) Why do some syscalls have `_' prefixes while others do not?
>c) How are the parameters to the libc syscall wrapper passed onto the 
>actual kernel-side implementation?
>
>Thank you for your time.
>
>Cheers,
>Anant