text: /*
   * Copyright (c) 2020 Intel Corporation
   *
   * SPDX-License-Identifier: Apache-2.0
   */
  
  #include <device.h>
  #include <shell/shell.h>
  #include <stdlib.h>
  
  static int memory_read(const struct shell *sh, mem_addr_t addr, uint8_t width)
  {
  	uint64_t value;
  	int err = 0;
  
  	switch (width) {
  	case 8:
  		value = sys_read8(addr);
  		break;
  	case 16:
  		value = sys_read16(addr);
  		break;
  	case 32:
  		value = sys_read32(addr);
  		break;
  	default:
  		shell_fprintf(sh, SHELL_NORMAL, "Incorrect data width\n");
  		err = -EINVAL;
  		break;
  	}
  
  	if (err == 0) {
  		shell_fprintf(sh, SHELL_NORMAL, "Read value 0x%lx\n", value);
  	}
  
  	return err;
  }
  
  static int memory_write(const struct shell *sh, mem_addr_t addr,
  			uint8_t width, uint64_t value)
  {
  	int err = 0;
  
  	switch (width) {
  	case 8:
  		sys_write8(value, addr);
  		break;
  	case 16:
  		sys_write16(value, addr);
  		break;
  	case 32:
  		sys_write32(value, addr);
  		break;
  	default:
  		shell_fprintf(sh, SHELL_NORMAL, "Incorrect data width\n");
  		err = -EINVAL;
  		break;
  	}
  
  	return err;
  }
  
  /* The syntax of the command is similar to busybox's devmem */
  static int cmd_devmem(const struct shell *sh, size_t argc, char **argv)
  {
  	mem_addr_t phys_addr, addr;
  	uint32_t value = 0;
  	uint8_t width;
  
  	if (argc < 2 || argc > 4) {
  		return -EINVAL;
  	}
  
  	phys_addr = strtoul(argv[1], NULL, 16);
  
  #if defined(CONFIG_MMU) || defined(CONFIG_PCIE)
  	device_map((mm_reg_t *)&addr, phys_addr, 0x100, K_MEM_CACHE_NONE);
  
  	shell_print(sh, "Mapped 0x%lx to 0x%lx\n", phys_addr, addr);
  #else
  	addr = phys_addr;
  #endif /* defined(CONFIG_MMU) || defined(CONFIG_PCIE) */
  
  	if (argc < 3) {
  		width = 32;
  	} else {
  		width = strtoul(argv[2], NULL, 10);
  	}
  
  	shell_fprintf(sh, SHELL_NORMAL, "Using data width %d\n", width);
  
  	if (argc <= 3) {
  		return memory_read(sh, addr, width);
  	}
  
  	/* If there are more then 3 arguments, that means we are going to write
  	 * this value at the address provided
  	 */
  
  	value = strtoul(argv[3], NULL, 16);
  
  	shell_fprintf(sh, SHELL_NORMAL, "Writing value 0x%lx\n", value);
  
  	return memory_write(sh, addr, width, value);
  }
  
  SHELL_CMD_REGISTER(devmem, NULL, "Read/write physical memory\""
  		   "devmem address [width [value]]", cmd_devmem);
  