#include <devices/nvram.h>
#include <palacios/vmm.h>
#include <palacios/vmm_types.h>

extern struct vmm_os_hooks *os_hooks;


#define NVRAM_REG_PORT  0x70
#define NVRAM_DATA_PORT 0x71



typedef enum {NVRAM_READY, NVRAM_REG_POSTED} nvram_state_t;


#define NVRAM_REG_MAX   256


// These are borrowed from Bochs, which borrowed from
// Ralf Brown's interupt list
#define NVRAM_REG_SEC                     0x00
#define NVRAM_REG_SEC_ALARM               0x01
#define NVRAM_REG_MIN                     0x02
#define NVRAM_REG_MIN_ALARM               0x03
#define NVRAM_REG_HOUR                    0x04
#define NVRAM_REG_HOUR_ALARM              0x05
#define NVRAM_REG_WEEK_DAY                0x06
#define NVRAM_REG_MONTH_DAY               0x07
#define NVRAM_REG_MONTH                   0x08
#define NVRAM_REG_YEAR                    0x09
#define NVRAM_REG_STAT_A                  0x0a
#define NVRAM_REG_STAT_B                  0x0b
#define NVRAM_REG_STAT_C                  0x0c
#define NVRAM_REG_STAT_D                  0x0d
#define NVRAM_REG_DIAGNOSTIC_STATUS       0x0e  
#define NVRAM_REG_SHUTDOWN_STATUS         0x0f
#define NVRAM_REG_EQUIPMENT_BYTE          0x14
#define NVRAM_REG_CSUM_HIGH               0x2e
#define NVRAM_REG_CSUM_LOW                0x2f
#define NVRAM_REG_IBM_CENTURY_BYTE        0x32  
#define NVRAM_REG_IBM_PS2_CENTURY_BYTE    0x37  



struct nvram_internal {
  nvram_state_t dev_state;
  uchar_t       thereg;
  uchar_t       mem_state[NVRAM_REG_MAX];
};





int nvram_reset_device(struct vm_device * dev)
{
  struct nvram_internal *data = (struct nvram_internal *) dev->private_data;
  
  data->dev_state = NVRAM_READY;
  data->thereg=0;
  
  return 0;

}





int nvram_start_device(struct vm_device *dev)
{
  return 0;
}


int nvram_stop_device(struct vm_device *dev)
{
  return 0;
}




int nvram_write_reg_port(ushort_t port,
			void * src, 
			uint_t length,
			struct vm_device * dev)
{
  struct nvram_internal *data = (struct nvram_internal *) dev->private_data;

  memcpy(&(data->thereg), src, 1);

  return 0;
}


int nvram_read_data_port(ushort_t port,
		       void   * dst, 
		       uint_t length,
		       struct vm_device * dev)
{
  struct nvram_internal *data = (struct nvram_internal *) dev->private_data;

  memcpy(dst, &(data->mem_state[data->thereg]), 1);

  return 0;
}

int nvram_write_data_port(ushort_t port,
			void * src, 
			uint_t length,
			struct vm_device * dev)
{
  struct nvram_internal *data = (struct nvram_internal *) dev->private_data;

  memcpy(&(data->mem_state[data->thereg]), src, 1);

  return 0;
}



int nvram_init_device(struct vm_device * dev) {
  struct nvram_internal *data = (struct nvram_internal *) dev->private_data;
 
  memset(data->mem_state, 0, NVRAM_REG_MAX);

  nvram_reset_device(dev);

  // hook ports
  dev_hook_io(dev, NVRAM_REG_PORT, NULL, &nvram_write_reg_port);
  dev_hook_io(dev, NVRAM_DATA_PORT, &nvram_read_data_port, &nvram_write_data_port);
  
  return 0;
}

int nvram_deinit_device(struct vm_device *dev)
{


  dev_unhook_io(dev, NVRAM_REG_PORT);
  dev_unhook_io(dev, NVRAM_DATA_PORT);

  nvram_reset_device(dev);
  return 0;
}





static struct vm_device_ops dev_ops = { 
  .init = nvram_init_device, 
  .deinit = nvram_deinit_device,
  .reset = nvram_reset_device,
  .start = nvram_start_device,
  .stop = nvram_stop_device,
};



struct vm_device *create_nvram() {
  struct nvram_internal * nvram_state = os_hooks->malloc(sizeof(struct nvram_internal));

  struct vm_device *device = create_device("NVRAM", &dev_ops, nvram_state);

  return device;
}