/*==========================================================================
* Issue a command to the network loader.
*
* The 'cmd' command structure should be allocated on the stack to
* ensure that it resides within the addressable range for the
* network loader, which runs in real mode.
*/
static UInt32 nbp(nbpCommandCode_t code, nbpCommand_u * cmd)
{
loader(code, GET_FP((UInt32) cmd));
// Must re-enable the A20 address line, the PXE firmware will
// disable the A20 line control.
//
enableA20();
return cmd->header.status;
}
static void notrace walk_stackframe(struct task_struct *task,
struct pt_regs *regs, bool (*fn)(unsigned long, void *), void *arg)
{
unsigned long fp, sp, pc;
if (regs) {
fp = GET_FP(regs);
sp = GET_USP(regs);
pc = GET_IP(regs);
} else if (task == NULL || task == current) {
const register unsigned long current_sp __asm__ ("sp");
fp = (unsigned long)__builtin_frame_address(0);
sp = current_sp;
pc = (unsigned long)walk_stackframe;
} else {
/* task blocked in __switch_to */
fp = task->thread.s[0];
sp = task->thread.sp;
pc = task->thread.ra;
}
for (;;) {
unsigned long low, high;
struct stackframe *frame;
if (unlikely(!__kernel_text_address(pc) || fn(pc, arg)))
break;
/* Validate frame pointer */
low = sp + sizeof(struct stackframe);
high = ALIGN(sp, THREAD_SIZE);
if (unlikely(fp < low || fp > high || fp & 0x7))
break;
/* Unwind stack frame */
frame = (struct stackframe *)fp - 1;
sp = fp;
fp = frame->fp;
pc = frame->ra - 0x4;
}
}
