Hi,
I try to understand some ppc-assembler-code but it is harder than
x86 to me because of the missing documentation. I have a big reference
from ibm here. And some websites which deal with this topic.
So I experiment now with the assembler code of c programms translated
with gcc -S file.c
For a simple Hello World programm I get lots of instructions in
assembler, used in a way, that I can not comprehend them using the ibm
reference.
Maybe someone can point me to a tutorial or if somebody has too much
time it would be nice if you comment the following shortened code out
of the c-helloworld.
.LC0: //I guess this means .LC0
.string "Hello World" //is a global string
.globl main //within the main label.
.type main, @function //whats that for?
main:
stwu 1,-32(1) //I do not understand this.
mflr 0 //Does this
stw 31,28(1) //setup some
stw 0,36(1) //GPRs for the
mr 31,1 //begin of the code??
lis 9,[EMAIL PROTECTED] //this is
la 3,[EMAIL PROTECTED](9) //fine
crxor 6,6,6 //this clears the contend of crb6 right?
bl printf //mhh..
li 0,0 //set the GPR0 to completly to zeros
mr 3,0 //why that?? since 0 OR 0 is 0 it just
//moves GPR0 to GRP3, right?
lwz 11,0(1) //GPR3 pointing to 0?
lwz 0,4(11) //GPR0 pointing to 4?
mtlr 0 //again this mt* function what does it?
lwz 31,-4(11) //...
mr 1,11 //..
blr //...
TIA
olliwolli
P.S.: I hope this is not totally off topic in this list
