void
sysrforkchild(Proc* child, Proc* parent)
{
Ureg *cureg;
// If STACKPAD is 1 things go very bad very quickly.
// But it is the right value ...
#define STACKPAD 1 /* for return PC? */
/*
* Add STACKPAD*BY2SE to the stack to account for
* - the return PC
* (NOT NOW) - trap's arguments (syscallnr, ureg)
*/
child->sched.sp = PTR2UINT(child->kstack+KSTACK-((sizeof(Ureg)+STACKPAD*BY2SE)));
child->sched.pc = PTR2UINT(sysrforkret);
cureg = (Ureg*)(child->sched.sp+STACKPAD*BY2SE);
memmove(cureg, parent->dbgreg, sizeof(Ureg));
/* Things from bottom of syscall which were never executed */
child->psstate = 0;
child->insyscall = 0;
//iprint("Child SP set tp %p\n", (void *)child->sched.sp);
fpusysrforkchild(child, parent);
}
/*
* Craft a return frame which will cause the child to pop out of
* the scheduler in user mode with the return register zero. Set
* pc to point to a l.s return function.
*/
void
forkchild(Proc *p, Ureg *ureg)
{
Ureg *cureg;
//print("%lud setting up for forking child %lud\n", up->pid, p->pid);
p->sched.sp = (ulong)p->kstack+KSTACK-sizeof(Ureg);
p->sched.pc = (ulong)forkret;
cureg = (Ureg*)(p->sched.sp);
memmove(cureg, ureg, sizeof(Ureg));
/* syscall returns 0 for child */
cureg->r0 = 0;
/* Things from bottom of syscall which were never executed */
p->psstate = 0;
p->insyscall = 0;
fpusysrforkchild(p, cureg, up);
}
void
sysrforkchild(Proc* child, Proc* parent)
{
Ureg *cureg;
/*
* Add 3*BY2SE to the stack to account for
* - the return PC
* - trap's arguments (syscallnr, ureg)
*/
child->sched.sp = PTR2UINT(child->kstack+KSTACK-(sizeof(Ureg)+3*BY2SE));
child->sched.pc = PTR2UINT(sysrforkret);
cureg = (Ureg*)(child->sched.sp+3*BY2SE);
memmove(cureg, parent->dbgreg, sizeof(Ureg));
/* Things from bottom of syscall which were never executed */
child->psstate = 0;
child->insyscall = 0;
fpusysrforkchild(child, parent);
}
