Rootovske heslo pro Virtual Box image je "OperacniSystemy"

Pro pridani noveho systemovaho volani provedeme:

1) nainstalujeme prekladac a zavisle baliky, zdrojaky jadra
2) zdrojaky rozbalime:
   rpmbuild -bp kernel.spec

3) Modifikujeme soubor
   /root/rpmbuild/BUILD/kernel-2.6.3/linux-2.6.31.i686/arch/x86/include/asm/unistd_32.h
   - pridame polozky pro nova systemova volani (symbolicky nazev)

4) Modifikujeme soubor
   /root/rpmbuild/BUILD/kernel-2.6.3/linux-2.6.31.i686/arch/x86/kernel/syscall_table_32.S
   specifikujeme jake funkce budou nova systemova volani obsluhovat

5) Funkce, ktere budou systemova volani obsluhovat pridame napr. do ipc/sem.c:


asmlinkage int sys_fce1(void)
{
 /* ... */
 return 8;
}

asmlinkage int sys_fce2(int a,int b)
{
 return a+b;
}

6) zkompilujeme jadro, v adresari /root/rpmbuild/BUILD/kernel-2.6.3/linux-2.6.31.i686 zavolame
   make

7) zkompilovane jadro zkopirujeme do /boot
   cp /root/rpmbuild/BUILD/kernel-2.6.3/linux-2.6.31.i686/arch/x86/boot/bzImage /boot

8) Editujeme boot manager a pridame polozku pro nove jadro
   vi /etc/grub.conf

9) Nabootujeme nove jadro

10) VYzkousime nova volani pomoci programu napr.:

#include <linux/unistd.h>
#include <stdio.h>

int main(void)
{
int y=syscall(337);
int x=syscall(338,4,3);
printf("const: %i, 4 a 3 je %i\n",y,x);
printf("UID: %i\n",getuid());
}