From: Albert Cahalan <albert@users.sourceforge.net>
To: linuxppc-dev@lists.linuxppc.org
Cc: damm@opensource.se, hollis@austin.ibm.com,
benh@kernel.crashing.org, ningerso@ruralcenter.org
Subject: Re: Runtime Altivec detection
Date: 08 Mar 2003 23:01:47 -0500 [thread overview]
Message-ID: <1047182509.1900.246.camel@cube> (raw)
For those of you needing to get at ELF note info
to determine CPU features and other things, here
is the code procps-3.1.x has been using. You'll
need the appropriate ID code; here I use AT_CLKTCK
to determine USER_HZ. Pass the ID code into this
function, and you get back the ELF note value.
//////////////////////////////////////////////////////////////////////////
#ifndef AT_CLKTCK
#define AT_CLKTCK 17 // frequency of times()
#endif
#define ERROR_CODE 42 // choose something better!
extern char** environ;
// for ELF executables, notes are pushed before environment and args
static unsigned long find_elf_note(unsigned long findme){
unsigned long *ep = (unsigned long *)environ;
while(*ep++);
while(*ep){
if(ep[0]==findme) return ep[1];
ep+=2;
}
return ERROR_CODE;
}
// Usage:
// Hertz = find_elf_note(AT_CLKTCK);
////////////////////////////////////////////////////////////////////////
** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/
next reply other threads:[~2003-03-09 4:01 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-03-09 4:01 Albert Cahalan [this message]
-- strict thread matches above, loose matches on Subject: below --
2003-03-08 2:02 Runtime Altivec detection Bill Fink
2003-03-08 2:11 ` Hollis Blanchard
2003-03-08 8:04 ` Bill Fink
2003-03-08 18:21 ` Nathan Ingersoll
2003-03-07 16:47 Nathan Ingersoll
2003-03-07 17:24 ` Dan Malek
2003-03-07 17:35 ` Nathan Ingersoll
2003-03-07 17:37 ` Anton Blanchard
2003-03-07 17:41 ` Benjamin Herrenschmidt
2003-03-07 17:52 ` Nathan Ingersoll
2003-03-07 18:55 ` Magnus Damm
2003-03-07 18:06 ` Benjamin Herrenschmidt
2003-03-07 18:18 ` Hollis Blanchard
2003-03-07 18:54 ` Magnus Damm
2003-03-07 18:08 ` Nathan Ingersoll
2003-03-07 19:44 ` Magnus Damm
2003-03-07 19:23 ` Nathan Ingersoll
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