/* 
 * 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>
#include <palacios/vm_guest_mem.h>

#define BUF_SIZE 1024

#define DEBUG_PORT1 0xc0c0
#define DEBUG_HCALL 0xc0c0

struct debug_state {
    char debug_buf[BUF_SIZE];
    uint_t debug_offset;

};


static int handle_gen_write(ushort_t port, void * src, uint_t length, struct vm_device * dev) {
    struct debug_state * state = (struct debug_state *)dev->private_data;

    state->debug_buf[state->debug_offset++] = *(char*)src;

    if ((*(char*)src == 0xa) ||  (state->debug_offset == (BUF_SIZE - 1))) {
	PrintDebug("VM_CONSOLE>%s", state->debug_buf);
	memset(state->debug_buf, 0, BUF_SIZE);
	state->debug_offset = 0;
    }

    return length;
}

static int handle_hcall(struct guest_info * info, uint_t hcall_id, void * priv_data) {
    struct vm_device * dev = (struct vm_device *)priv_data;
    struct debug_state * state = (struct debug_state *)dev->private_data;

    int msg_len = info->vm_regs.rcx;
    addr_t msg_gpa = info->vm_regs.rbx;
    int buf_is_va = info->vm_regs.rdx;

    if (msg_len >= BUF_SIZE) {
	PrintError("Console message too large for buffer (len=%d)\n", msg_len);
	return -1;
    }

    if (buf_is_va == 1) {
	if (read_guest_va_memory(info, msg_gpa, msg_len, (uchar_t *)state->debug_buf) != msg_len) {
	    PrintError("Could not read debug message\n");
	    return -1;
	}
    } else {
	if (read_guest_pa_memory(info, msg_gpa, msg_len, (uchar_t *)state->debug_buf) != msg_len) {
	    PrintError("Could not read debug message\n");
	    return -1;
	}
    }	

    state->debug_buf[msg_len] = 0;

    PrintDebug("VM_CONSOLE>%s\n", state->debug_buf);

    return 0;
}



static int debug_free(struct vm_device * dev) {
    v3_dev_unhook_io(dev, DEBUG_PORT1);


    return 0;
};




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




static int debug_init(struct guest_info * vm, v3_cfg_tree_t * cfg) {
    struct debug_state * state = NULL;
    char * name = v3_cfg_val(cfg, "name");

    state = (struct debug_state *)V3_Malloc(sizeof(struct debug_state));

    PrintDebug("Creating OS Debug Device\n");

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


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

    v3_dev_hook_io(dev, DEBUG_PORT1,  NULL, &handle_gen_write);
    v3_register_hypercall(vm, DEBUG_HCALL, handle_hcall, dev);

    state->debug_offset = 0;
    memset(state->debug_buf, 0, BUF_SIZE);
  
    return 0;
}


device_register("OS_DEBUG", debug_init)