You can find sth useful in the following link, buddy :) http://osdev.neopages.net/tutorials/gccasmtut.php?the_id=68 On Friday 02 July 2004 17:44, Borislav Petkov wrote: > Hi there guys, > a new day - a new question :)) > > I've been trying to figure out today how BUG() works, it is inline assembly, > again: > > <from include/asm-i386/bug.h:12> > 12 #if 1 /* Set to zero for a slightly smaller kernel */ > 13 #define BUG() \ > 14 __asm__ __volatile__( "ud2\n" \ > 15 "\t.word %c0\n" \ > 16 "\t.long %c1\n" \ > 17 : : "i" (__LINE__), "i" (__FILE__)) > > I know that ud2 means undefined and generates invalid opcode exception, .word > and .long are as directives, "i" as an input operand constraint is an > immediate integer operand with constant value, but what I can't understand > after looking into the as and gcc manuals is: > > 1. what does the c mean in the constraint %c0, %c1 resp.? > 2. Where does the compiler get those __LINE__ and __FILE__ from? > > Thanks in advance for your patience, > Boris. > > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > > > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
