/* init.c - generic U-Boot initialization and finalization */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2013  Free Software Foundation, Inc.
 *
 *  GRUB is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  GRUB is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */


#include <grub/env.h>
#include <grub/kernel.h>
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/offsets.h>
#include <grub/term.h>
#include <grub/time.h>
#include <grub/machine/kernel.h>
#include <grub/uboot/console.h>
#include <grub/uboot/disk.h>
#include <grub/uboot/uboot.h>
#include <grub/uboot/api_public.h>
#include <grub/cpu/system.h>
#include <grub/cache.h>

extern char __bss_start[];
extern char _end[];
extern grub_size_t grub_total_module_size;
static unsigned long timer_start;

void
grub_exit (void)
{
  grub_uboot_return (0);
}

static grub_uint64_t
uboot_timer_ms (void)
{
  static grub_uint32_t last = 0, high = 0;
  grub_uint32_t cur = grub_uboot_get_timer (timer_start);
  if (cur < last)
    high++;
  last = cur;
  return (((grub_uint64_t) high) << 32) | cur;
}

#ifdef __arm__
static grub_uint64_t
rpi_timer_ms (void)
{
  static grub_uint32_t last = 0, high = 0;
  grub_uint32_t cur = *(volatile grub_uint32_t *) 0x20003004;
  if (cur < last)
    high++;
  last = cur;
  return grub_divmod64 ((((grub_uint64_t) high) << 32) | cur, 1000, 0);
}
#endif

void
grub_machine_init (void)
{
  int ver;

  /* First of all - establish connection with U-Boot */
  ver = grub_uboot_api_init ();
  if (!ver)
    {
      /* Don't even have a console to log errors to... */
      grub_exit ();
    }
  else if (ver > API_SIG_VERSION)
    {
      /* Try to print an error message */
      grub_uboot_puts ("invalid U-Boot API version\n");
    }

  /* Initialize the console so that GRUB can display messages.  */
  grub_console_init_early ();

  /* Enumerate memory and initialize the memory management system. */
  grub_uboot_mm_init ();

  /* Should be earlier but it needs memalign.  */
#ifdef __arm__
  grub_arm_enable_caches_mmu ();
#endif

  grub_dprintf ("init", "__bss_start: %p\n", __bss_start);
  grub_dprintf ("init", "_end: %p\n", _end);
  grub_dprintf ("init", "grub_modbase: %p\n", (void *) grub_modbase);
  grub_dprintf ("init", "grub_modules_get_end(): %p\n",
		(void *) grub_modules_get_end ());

  /* Initialise full terminfo support */
  grub_console_init_lately ();

  /* Enumerate uboot devices */
  grub_uboot_probe_hardware ();

  /* Initialise timer */
#ifdef __arm__
  if (grub_uboot_get_machine_type () == GRUB_ARM_MACHINE_TYPE_RASPBERRY_PI)
    {
      grub_install_get_time_ms (rpi_timer_ms);
    }
  else
#endif
    {
      timer_start = grub_uboot_get_timer (0);
      grub_install_get_time_ms (uboot_timer_ms);
    }

  /* Initialize  */
  grub_ubootdisk_init ();
}


void
grub_machine_fini (int flags __attribute__ ((unused)))
{
}

/*
 * grub_machine_get_bootlocation():
 *   Called from kern/main.c, which expects a device name (minus parentheses)
 *   and a filesystem path back, if any are known.
 *   Any returned values must be pointers to dynamically allocated strings.
 */
void
grub_machine_get_bootlocation (char **device, char **path)
{
  char *tmp;

  tmp = grub_uboot_env_get ("grub_bootdev");
  if (tmp)
    {
      *device = grub_strdup (tmp);
      if (*device == NULL)
	return;
    }
  else
    *device = NULL;

  tmp = grub_uboot_env_get ("grub_bootpath");
  if (tmp)
    {
      *path = grub_strdup (tmp);
      if (*path == NULL)
	return;
    }
  else
    *path = NULL;
}

void
grub_uboot_fini (void)
{
  grub_ubootdisk_fini ();
  grub_console_fini ();
}