/*
 * main.c - main routine of Gnuk
 *
 * Copyright (C) 2010, 2011, 2012, 2013, 2015, 2016
 *               Free Software Initiative of Japan
 * Author: NIIBE Yutaka <gniibe@fsij.org>
 *
 * This file is a part of Gnuk, a GnuPG USB Token implementation.
 *
 * Gnuk 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.
 *
 * Gnuk 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include <stdint.h>
#include <string.h>
#include <chopstx.h>
#include <eventflag.h>

#include "config.h"

#include "sys.h"
#include "adc.h"
#include "gnuk.h"
#include "usb_lld.h"
#include "usb-cdc.h"
#include "random.h"
#include "mcu/stm32f103.h"


/*
 * main thread does 1-bit LED display output
 */
#define LED_TIMEOUT_INTERVAL	(75*1000)
#define LED_TIMEOUT_ZERO	(25*1000)
#define LED_TIMEOUT_ONE		(100*1000)
#define LED_TIMEOUT_STOP	(200*1000)


#define ID_OFFSET (2+SERIALNO_STR_LEN*2)
static void
device_initialize_once (void)
{
  const uint8_t *p = &gnuk_string_serial[ID_OFFSET];

  if (p[0] == 0xff && p[1] == 0xff && p[2] == 0xff && p[3] == 0xff)
    {
      /*
       * This is the first time invocation.
       * Setup serial number by unique device ID.
       */
      const uint8_t *u = unique_device_id () + 8;
      int i;

      for (i = 0; i < 4; i++)
	{
	  uint8_t b = u[3-i];
	  uint8_t nibble;

	  nibble = (b >> 4);
	  nibble += (nibble >= 10 ? ('A' - 10) : '0');
	  flash_put_data_internal (&p[i*4], nibble);
	  nibble = (b & 0x0f);
	  nibble += (nibble >= 10 ? ('A' - 10) : '0');
	  flash_put_data_internal (&p[i*4+2], nibble);
	}
    }
}


static volatile uint8_t fatal_code;
static struct eventflag led_event;

static void display_fatal_code (void)
{
  while (1)
    {
      set_led (1);
      chopstx_usec_wait (LED_TIMEOUT_ZERO);
      set_led (0);
      chopstx_usec_wait (LED_TIMEOUT_INTERVAL);
      set_led (1);
      chopstx_usec_wait (LED_TIMEOUT_ZERO);
      set_led (0);
      chopstx_usec_wait (LED_TIMEOUT_INTERVAL);
      set_led (1);
      chopstx_usec_wait (LED_TIMEOUT_ZERO);
      set_led (0);
      chopstx_usec_wait (LED_TIMEOUT_STOP);
      set_led (1);
      if (fatal_code & 1)
	chopstx_usec_wait (LED_TIMEOUT_ONE);
      else
	chopstx_usec_wait (LED_TIMEOUT_ZERO);
      set_led (0);
      chopstx_usec_wait (LED_TIMEOUT_INTERVAL);
      set_led (1);
      if (fatal_code & 2)
	chopstx_usec_wait (LED_TIMEOUT_ONE);
      else
	chopstx_usec_wait (LED_TIMEOUT_ZERO);
      set_led (0);
      chopstx_usec_wait (LED_TIMEOUT_INTERVAL);
      set_led (1);
      chopstx_usec_wait (LED_TIMEOUT_STOP);
      set_led (0);
      chopstx_usec_wait (LED_TIMEOUT_INTERVAL*10);
    }
}

static uint8_t led_inverted;

static void emit_led (int on_time, int off_time)
{
  set_led (!led_inverted);
  chopstx_usec_wait (on_time);
  set_led (led_inverted);
  chopstx_usec_wait (off_time);
}

static void display_status_code (void)
{
  enum icc_state icc_state = *icc_state_p;

  if (icc_state == ICC_STATE_START)
    emit_led (LED_TIMEOUT_ONE, LED_TIMEOUT_STOP);
  else
    /* OpenPGP card thread is running */
    {
      emit_led ((auth_status & AC_ADMIN_AUTHORIZED)?
		LED_TIMEOUT_ONE : LED_TIMEOUT_ZERO, LED_TIMEOUT_INTERVAL);
      emit_led ((auth_status & AC_OTHER_AUTHORIZED)?
		LED_TIMEOUT_ONE : LED_TIMEOUT_ZERO, LED_TIMEOUT_INTERVAL);
      emit_led ((auth_status & AC_PSO_CDS_AUTHORIZED)?
		LED_TIMEOUT_ONE : LED_TIMEOUT_ZERO, LED_TIMEOUT_INTERVAL);

      if (icc_state == ICC_STATE_WAIT)
	chopstx_usec_wait (LED_TIMEOUT_STOP * 2);
      else
	{
	  chopstx_usec_wait (LED_TIMEOUT_INTERVAL);
	  emit_led (icc_state == ICC_STATE_RECEIVE?
		    LED_TIMEOUT_ONE : LED_TIMEOUT_ZERO, LED_TIMEOUT_STOP);
	}
    }
}

void
led_blink (int spec)
{
  if (spec == LED_START_COMMAND || spec == LED_FINISH_COMMAND)
    {
      led_inverted = (spec == LED_START_COMMAND);
      spec = LED_SYNC;
    }

  eventflag_signal (&led_event, spec);
}

/*
 * In Gnuk 1.0.[12], reGNUal was not relocatable.
 * Now, it's relocatable, but we need to calculate its entry address
 * based on it's pre-defined address.
 */
#define REGNUAL_START_ADDRESS_COMPATIBLE 0x20001400
static uint32_t
calculate_regnual_entry_address (const uint8_t *addr)
{
  const uint8_t *p = addr + 4;
  uint32_t v = p[0] + (p[1] << 8) + (p[2] << 16) + (p[3] << 24);

  v -= REGNUAL_START_ADDRESS_COMPATIBLE;
  v += (uint32_t)addr;
  return v;
}

extern uint8_t __process1_stack_base__, __process1_stack_size__;
const uint32_t __stackaddr_ccid = (uint32_t)&__process1_stack_base__;
const size_t __stacksize_ccid = (size_t)&__process1_stack_size__;

#define PRIO_CCID 3
#define PRIO_MAIN 5

extern void *ccid_thread (void *arg);

static void gnuk_malloc_init (void);


extern uint32_t bDeviceState;

/*
 * Entry point.
 */
int
main (int argc, char *argv[])
{
  uint32_t entry;
  chopstx_t ccid_thd;

  (void)argc;
  (void)argv;

  gnuk_malloc_init ();

  flash_unlock ();
  device_initialize_once ();

  adc_init ();

  eventflag_init (&led_event);

  random_init ();

#ifdef DEBUG
  stdout_init ();
#endif

  ccid_thd = chopstx_create (PRIO_CCID, __stackaddr_ccid, __stacksize_ccid,
			     ccid_thread, NULL);

#ifdef PINPAD_CIR_SUPPORT
  cir_init ();
#endif
#ifdef PINPAD_DND_SUPPORT
  msc_init ();
#endif

  chopstx_setpriority (PRIO_MAIN);

  while (1)
    {
      if (bDeviceState != UNCONNECTED)
	break;

      chopstx_usec_wait (250*1000);
    }

  while (1)
    {
      eventmask_t m;

      m = eventflag_wait (&led_event);
      switch (m)
	{
	case LED_ONESHOT:
	  emit_led (100*1000, LED_TIMEOUT_STOP);
	  break;
	case LED_TWOSHOTS:
	  emit_led (50*1000, 50*1000);
	  emit_led (50*1000, LED_TIMEOUT_STOP);
	  break;
	case LED_SHOW_STATUS:
	  display_status_code ();
	  break;
	case LED_FATAL:
	  display_fatal_code ();
	  break;
	case LED_SYNC:
	  set_led (led_inverted);
	  break;
	case LED_GNUK_EXEC:
	  goto exec;
	default:
	  emit_led (LED_TIMEOUT_ZERO, LED_TIMEOUT_STOP);
	  break;
	}
    }

 exec:
  random_fini ();

  set_led (1);
  usb_lld_shutdown ();

  /* Finish application.  */
  chopstx_join (ccid_thd, NULL);

  /* Set vector */
  SCB->VTOR = (uint32_t)&_regnual_start;
  entry = calculate_regnual_entry_address (&_regnual_start);
#ifdef DFU_SUPPORT
#define FLASH_SYS_START_ADDR 0x08000000
#define FLASH_SYS_END_ADDR (0x08000000+0x1000)
#define CHIP_ID_REG ((uint32_t *)0xE0042000)
  {
    extern uint8_t _sys;
    uint32_t addr;
    handler *new_vector = (handler *)FLASH_SYS_START_ADDR;
    void (*func) (void (*)(void)) = (void (*)(void (*)(void)))new_vector[9];
    uint32_t flash_page_size = 1024; /* 1KiB default */

   if ((*CHIP_ID_ADDR)&0x07 == 0x04) /* High dencity device.  */
     flash_page_size = 2048; /* It's 2KiB. */

    /* Kill DFU */
    for (addr = FLASH_SYS_START_ADDR; addr < FLASH_SYS_END_ADDR;
	 addr += flash_page_size)
      flash_erase_page (addr);

    /* copy system service routines */
    flash_write (FLASH_SYS_START_ADDR, &_sys, 0x1000);

    /* Leave Gnuk to exec reGNUal */
    (*func) ((void (*)(void))entry);
    for (;;);
  }
#else
  /* Leave Gnuk to exec reGNUal */
  flash_erase_all_and_exec ((void (*)(void))entry);
#endif

  /* Never reached */
  return 0;
}

void
fatal (uint8_t code)
{
  extern void _write (const char *s, int len);

  fatal_code = code;
  eventflag_signal (&led_event, LED_FATAL);
  _write ("fatal\r\n", 7);
  for (;;);
}

/*
 * Malloc for Gnuk.
 *
 * Each memory chunk has header with size information.
 * The size of chunk is at least 16.
 *
 * Free memory is managed by FREE_LIST.
 *
 * When it is managed in FREE_LIST, three pointers, ->NEXT, ->PREV,
 * and ->NEIGHBOR is used.  NEXT and PREV is to implement doubly
 * linked list.  NEIGHBOR is to link adjacent memory chunk to be
 * reclaimed to system.
 */

extern uint8_t __heap_base__[];
extern uint8_t __heap_end__[];

#define MEMORY_END (__heap_end__)
#define MEMORY_ALIGNMENT 16
#define MEMORY_ALIGN(n) (((n) + MEMORY_ALIGNMENT - 1) & ~(MEMORY_ALIGNMENT - 1))

static uint8_t *heap_p;
static chopstx_mutex_t malloc_mtx;

struct mem_head {
  uint32_t size;
  /**/
  struct mem_head *next, *prev;	/* free list chain */
  struct mem_head *neighbor;	/* backlink to neighbor */
};

static struct mem_head *free_list;

static void
gnuk_malloc_init (void)
{
  chopstx_mutex_init (&malloc_mtx);
  heap_p = __heap_base__;
  free_list = NULL;
}

static void *
sbrk (size_t size)
{
  void *p = (void *)heap_p;

  if ((size_t)(MEMORY_END - heap_p) < size)
    return NULL;

  heap_p += size;
  return p;
}

static void
remove_from_free_list (struct mem_head *m)
{
  if (m->prev)
    m->prev->next = m->next;
  else
    free_list = m->next;
  if (m->next)
    m->next->prev = m->prev;
}


void *
gnuk_malloc (size_t size)
{
  struct mem_head *m;
  struct mem_head *m0;

  size = MEMORY_ALIGN (size + sizeof (uint32_t));

  chopstx_mutex_lock (&malloc_mtx);
  DEBUG_INFO ("malloc: ");
  DEBUG_SHORT (size);
  m = free_list;

  while (1)
    {
      if (m == NULL)
	{
	  m = (struct mem_head *)sbrk (size);
	  if (m)
	    m->size = size;
	  break;
	}

      if (m->size == size)
	{
	  remove_from_free_list (m);
	  m0 = free_list;
	  while (m0)
	    if (m0->neighbor == m)
	      m0->neighbor = NULL;
	    else
	      m0 = m0->next;
	  break;
	}

      m = m->next;
    }

  chopstx_mutex_unlock (&malloc_mtx);
  if (m == NULL)
    {
      DEBUG_WORD (0);
      return m;
    }
  else
    {
      DEBUG_WORD ((uint32_t)m + sizeof (uint32_t));
      return (void *)m + sizeof (uint32_t);
    }
}


void
gnuk_free (void *p)
{
  struct mem_head *m = (struct mem_head *)((void *)p - sizeof (uint32_t));
  struct mem_head *m0;

  chopstx_mutex_lock (&malloc_mtx);
  m0 = free_list;
  DEBUG_INFO ("free: ");
  DEBUG_SHORT (m->size);
  DEBUG_WORD ((uint32_t)p);

  m->neighbor = NULL;
  while (m0)
    {
      if ((void *)m + m->size == (void *)m0)
	m0->neighbor = m;
      else if ((void *)m0 + m0->size == (void *)m)
	m->neighbor = m0;

      m0 = m0->next;
    }

  if ((void *)m + m->size == heap_p)
    {
      struct mem_head *mn = m->neighbor;

      heap_p -= m->size;
      while (mn)
	{
	  heap_p -= mn->size;
	  remove_from_free_list (mn);
	  mn = mn->neighbor;
	}
    }
  else
    {
      m->next = free_list;
      m->prev = NULL;
      if (free_list)
	free_list->prev = m;
      free_list = m;
    }

  chopstx_mutex_unlock (&malloc_mtx);
}