asm_access.h

/*
 * Copyright (C) 2021, 2024 Kernkonzept GmbH.
 * Author(s): Jakub Jermar <jakub.jermar@kernkonzept.com>
 *
 * License: see LICENSE.spdx (in this directory or the directories above)
 */
 
#pragma once
 
#include <l4/sys/l4int.h>
 
namespace Asm_access {
 
inline
l4_uint8_t
read(l4_uint8_t const *mem)
{
  l4_uint8_t val;
 
  asm volatile ("movb %[mem], %[val]" : [val] "=q" (val) : [mem] "m" (*mem));
 
  return val;
}
 
inline
l4_uint16_t
read(l4_uint16_t const *mem)
{
  l4_uint16_t val;
 
  asm volatile ("movw %[mem], %[val]" : [val] "=r" (val) : [mem] "m" (*mem));
 
  return val;
}
 
inline
l4_uint32_t
read(l4_uint32_t const *mem)
{
  l4_uint32_t val;
 
  asm volatile ("movl %[mem], %[val]" : [val] "=r" (val) : [mem] "m" (*mem));
 
  return val;
}
 
inline
void
write(l4_uint8_t val, l4_uint8_t *mem)
{
  asm volatile ("movb %[val], %[mem]" :[mem]  "=m" (*mem) : [val] "qi" (val));
}
 
inline
void
write(l4_uint16_t val, l4_uint16_t *mem)
{
  asm volatile ("movw %[val], %[mem]" : [mem] "=m" (*mem) : [val] "ri" (val));
}
 
inline
void
write(l4_uint32_t val, l4_uint32_t *mem)
{
  asm volatile ("movl %[val], %[mem]" : [mem] "=m" (*mem) : [val] "ri" (val));
}
 
}