arch/arm/imx-common/imx_bootaux.c

   1 /*
   2  * Copyright (C) 2016 Freescale Semiconductor, Inc.
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <command.h>
   9
  10 /* Allow for arch specific config before we boot */
  11 static int __arch_auxiliary_core_up(u32 core_id, u32 boot_private_data)
  12 {
  13         /* please define platform specific arch_auxiliary_core_up() */
  14         return CMD_RET_FAILURE;
  15 }
  16
  17 int arch_auxiliary_core_up(u32 core_id, u32 boot_private_data)
  18         __attribute__((weak, alias("__arch_auxiliary_core_up")));
  19
  20 /* Allow for arch specific config before we boot */
  21 static int __arch_auxiliary_core_check_up(u32 core_id)
  22 {
  23         /* please define platform specific arch_auxiliary_core_check_up() */
  24         return 0;
  25 }
  26
  27 int arch_auxiliary_core_check_up(u32 core_id)
  28         __attribute__((weak, alias("__arch_auxiliary_core_check_up")));
  29
  30 /*
  31  * To i.MX6SX and i.MX7D, the image supported by bootaux needs
  32  * the reset vector at the head for the image, with SP and PC
  33  * as the first two words.
  34  *
  35  * Per the cortex-M reference manual, the reset vector of M4 needs
  36  * to exist at 0x0 (TCMUL). The PC and SP are the first two addresses
  37  * of that vector.  So to boot M4, the A core must build the M4's reset
  38  * vector with getting the PC and SP from image and filling them to
  39  * TCMUL. When M4 is kicked, it will load the PC and SP by itself.
  40  * The TCMUL is mapped to (M4_BOOTROM_BASE_ADDR) at A core side for
  41  * accessing the M4 TCMUL.
  42  */
  43 int do_bootaux(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
  44 {
  45         ulong addr;
  46         int ret, up;
  47
  48         if (argc < 2)
  49                 return CMD_RET_USAGE;
  50
  51         up = arch_auxiliary_core_check_up(0);
  52         if (up) {
  53                 printf("## Auxiliary core is already up\n");
  54                 return CMD_RET_SUCCESS;
  55         }
  56
  57         addr = simple_strtoul(argv[1], NULL, 16);
  58
  59         printf("## Starting auxiliary core at 0x%08lX ...\n", addr);
  60
  61         ret = arch_auxiliary_core_up(0, addr);
  62         if (ret)
  63                 return CMD_RET_FAILURE;
  64
  65         return CMD_RET_SUCCESS;
  66 }
  67
  68 U_BOOT_CMD(
  69         bootaux, CONFIG_SYS_MAXARGS, 1, do_bootaux,
  70         "Start auxiliary core",
  71         ""
  72 );