/* 
 * This file is part of the Palacios Virtual Machine Monitor developed
 * by the V3VEE Project with funding from the United States National 
 * Science Foundation and the Department of Energy.  
 *
 * The V3VEE Project is a joint project between Northwestern University
 * and the University of New Mexico.  You can find out more at 
 * http://www.v3vee.org
 *
 * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu> 
 * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org> 
 * All rights reserved.
 *
 * Author: Jack Lange <jarusl@cs.northwestern.edu>
 *
 * This is free software.  You are permitted to use,
 * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
 */

#include <palacios/vmm.h>
#include <palacios/vmm_dev_mgr.h>


#ifndef CONFIG_DEBUG_RAMDISK
#undef PrintDebug
#define PrintDebug(fmt, args...)
#endif

struct disk_state {
    uint8_t * disk_image;
    uint32_t capacity; // in bytes
};


static int read(uint8_t * buf, uint64_t lba, uint64_t num_bytes, void * private_data) {
    struct disk_state * disk = (struct disk_state *)private_data;

    PrintDebug("Reading %d bytes from %p to %p\n", (uint32_t)num_bytes, (uint8_t *)(disk->disk_image + lba), buf);

    memcpy(buf, (uint8_t *)(disk->disk_image + lba), num_bytes);

    return 0;
}


static int write(uint8_t * buf, uint64_t lba, uint64_t num_bytes, void * private_data) {
    struct disk_state * disk = (struct disk_state *)private_data;

    PrintDebug("Writing %d bytes from %p to %p\n", (uint32_t)num_bytes,  buf, (uint8_t *)(disk->disk_image + lba));

    memcpy((uint8_t *)(disk->disk_image + lba), buf, num_bytes);

    return 0;
}


static uint64_t get_capacity(void * private_data) {
    struct disk_state * disk = (struct disk_state *)private_data;

    PrintDebug("Querying RAMDISK capacity %d\n", 
	       (uint32_t)(disk->capacity));

    return disk->capacity;
}

static struct v3_dev_blk_ops blk_ops = {
    .read = read, 
    .write = write,
    .get_capacity = get_capacity,
};




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

static struct v3_device_ops dev_ops = {
    .free = disk_free,
    .reset = NULL,
    .start = NULL,
    .stop = NULL,
};




static int disk_init(struct guest_info * vm, v3_cfg_tree_t * cfg) {
    struct disk_state * disk = NULL;
    struct v3_cfg_file * file = NULL;
    char * name = v3_cfg_val(cfg, "name");
    char * filename = v3_cfg_val(cfg, "file");

    v3_cfg_tree_t * frontend_cfg = v3_cfg_subtree(cfg, "frontend");

    disk = (struct disk_state *)V3_Malloc(sizeof(struct disk_state));
    memset(disk, 0, sizeof(struct disk_state));


    if (!filename) {
	PrintError("Missing filename (%s) for %s\n", filename, name);
	return -1;
    }

    file = v3_cfg_get_file(vm, filename);

    if (!file) {
	PrintError("Invalid ramdisk file: %s\n", filename);
	return -1;
    }

    disk->disk_image = file->data;
    disk->capacity = file->size;
    PrintDebug("Registering RAMDISK at %p (size=%d)\n", 
	       (void *)file->data, (uint32_t)file->size);

    struct vm_device * dev = v3_allocate_device(name, &dev_ops, disk);

    if (v3_attach_device(vm, dev) == -1) {
	PrintError("Could not attach device %s\n", name);
	return -1;
    }

    if (v3_dev_connect_blk(vm, v3_cfg_val(frontend_cfg, "tag"), 
			   &blk_ops, frontend_cfg, disk) == -1) {
	PrintError("Could not connect %s to frontend %s\n", 
		   name, v3_cfg_val(frontend_cfg, "tag"));
	return -1;
    }
    

    return 0;
}


device_register("RAMDISK", disk_init)