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/* $OpenBSD: uthread_machdep.c,v 1.2 2004/02/21 05:29:16 drahn Exp $ */
/* David Leonard, <d@csee.uq.edu.au>. Public domain */
#include <pthread.h>
#include "pthread_private.h"
#define ALIGNBYTES 0x7
/* Register save frame as it appears on the stack */
struct frame {
int r[12-4];
int fp; /* r12 */
int ip; /* r13 */
int lr; /* r14 */
int cpsr;
double fpr[6]; /* sizeof(fp)+sizeof(fs) == 52 */
int fs;
/* The rest are only valid in the initial frame */
int next_fp;
int next_ip;
int next_lr;
int oldpc;
};
/*
* Given a stack and an entry function, initialise a state
* structure that can be later switched to.
*/
void
_thread_machdep_init(statep, base, len, entry)
struct _machdep_state* statep;
void *base;
int len;
void (*entry)(void);
{
struct frame *f;
int scratch;
/* Locate the initial frame, aligned at the top of the stack */
f = (struct frame *)(((int)base + len - sizeof *f) & ~ALIGNBYTES);
f->fp = (int)&f->next_fp;
f->ip = (int)0;
f->lr = (int)entry;
f->next_fp = 0; /* for gdb */
f->next_lr = 0; /* for gdb */
/* Initialise the new thread with all the state from this thread. */
__asm__ volatile ("mrs %0, cpsr_all; str %0, [%2, #0]"
: "=r"(scratch) : "0"(scratch), "r" (&f->cpsr));
__asm__ volatile ("stmia %0, {r4-r12}":: "r"(&f->r[0]));
#ifndef __VFP_FP__
__asm__ volatile ("sfm f4, 4, [%0], #0":: "r"(&f->fpr[0]));
__asm__ volatile ("rfs 0; stfd 0, %0" : "=m"(f->fs));
#endif
statep->frame = (int)f;
}
/*
* No-op float saves.
* (Floating point registers were saved in _thread_machdep_switch())
*/
void
_thread_machdep_save_float_state(statep)
struct _machdep_state* statep;
{
#ifndef __VFP_FP__
#error finish FP save
#endif
}
void
_thread_machdep_restore_float_state(statep)
struct _machdep_state* statep;
{
#ifndef __VFP_FP__
#error finish FP save
#endif
}
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