text: // SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
  /* Copyright 2013-2017 IBM Corp. */
  
  #include <skiboot.h>
  #include <opal.h>
  #include <mem_region.h>
  #include <lock.h>
  
  static struct mem_region *nvram_region;
  static struct lock fake_nvram_lock = LOCK_UNLOCKED;
  
  int fake_nvram_info(uint32_t *total_size)
  {
  	nvram_region = find_mem_region("ibm,fake-nvram");
  
  	if (!nvram_region)
  		return OPAL_HARDWARE;
  
  	*total_size = nvram_region->len;
  
  	return OPAL_SUCCESS;
  }
  
  int fake_nvram_start_read(void *dst, uint32_t src, uint32_t len)
  {
  	if (!nvram_region)
  		return -ENODEV;
  
  	lock(&fake_nvram_lock);
  	memcpy(dst, (void *) (nvram_region->start + src), len);
  	unlock(&fake_nvram_lock);
  
  	nvram_read_complete(true);
  
  	return 0;
  }
  
  int fake_nvram_write(uint32_t offset, void *src, uint32_t size)
  {
  	if (!nvram_region)
  		return OPAL_HARDWARE;
  
  	lock(&fake_nvram_lock);
  	memcpy((void *) (nvram_region->start + offset), src, size);
  	unlock(&fake_nvram_lock);
  
  	return 0;
  }
  
  