Palacios Public Git Repository

To checkout Palacios execute

  git clone http://v3vee.org/palacios/palacios.web/palacios.git
This will give you the master branch. You probably want the devel branch or one of the release branches. To switch to the devel branch, simply execute
  cd palacios
  git checkout --track -b devel origin/devel
The other branches are similar.


HVM configuration logic (create mptables, acpi tables, etc, based on ROS config)
[palacios.git] / palacios / src / devices / nvram.c
index fb5b9eb..f15795f 100644 (file)
@@ -1,23 +1,55 @@
-#include <devices/nvram.h>
+/* 
+ * 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, Peter Dinda <pdinda@northwestern.edu> 
+ * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org> 
+ * All rights reserved.
+ *
+ * Author: Peter Dinda <pdinda@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_dev_mgr.h>
 #include <palacios/vmm.h>
 #include <palacios/vmm_types.h>
 
-extern struct vmm_os_hooks *os_hooks;
+#include <palacios/vmm_lock.h>
+
+#include <devices/ide.h>
+#include <palacios/vmm_intr.h>
+#include <palacios/vmm_host_events.h>
+#include <palacios/vm_guest.h>
+
+
+#ifndef V3_CONFIG_DEBUG_NVRAM
+#undef PrintDebug
+#define PrintDebug(fmt, args...)
+#endif
 
 
 #define NVRAM_REG_PORT  0x70
 #define NVRAM_DATA_PORT 0x71
 
+#define NVRAM_RTC_IRQ   0x8
 
 
-typedef enum {NVRAM_READY,NVRAM_REG_POSTED} nvram_state_t;
+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
+// Ralf Brown's interupt list, and extended
 #define NVRAM_REG_SEC                     0x00
 #define NVRAM_REG_SEC_ALARM               0x01
 #define NVRAM_REG_MIN                     0x02
@@ -34,67 +66,689 @@ typedef enum {NVRAM_READY,NVRAM_REG_POSTED} nvram_state_t;
 #define NVRAM_REG_STAT_D                  0x0d
 #define NVRAM_REG_DIAGNOSTIC_STATUS       0x0e  
 #define NVRAM_REG_SHUTDOWN_STATUS         0x0f
+
+#define NVRAM_IBM_HD_DATA                 0x12
+#define NVRAM_IDE_TRANSLATION             0x39
+
+#define NVRAM_REG_FLOPPY_TYPE             0x10
 #define NVRAM_REG_EQUIPMENT_BYTE          0x14
+
+#define NVRAM_REG_BASE_MEMORY_HIGH        0x16
+#define NVRAM_REG_BASE_MEMORY_LOW         0x15
+
+#define NVRAM_REG_EXT_MEMORY_HIGH         0x18
+#define NVRAM_REG_EXT_MEMORY_LOW          0x17
+
+#define NVRAM_REG_EXT_MEMORY_2ND_HIGH     0x31
+#define NVRAM_REG_EXT_MEMORY_2ND_LOW      0x30
+
+#define NVRAM_REG_BOOTSEQ_OLD             0x2d
+
+#define NVRAM_REG_AMI_BIG_MEMORY_HIGH     0x35
+#define NVRAM_REG_AMI_BIG_MEMORY_LOW      0x34
+
 #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  
 
+#define NVRAM_REG_BOOTSEQ_NEW_FIRST       0x3D
+#define NVRAM_REG_BOOTSEQ_NEW_SECOND      0x38
+
+#define CHECKSUM_REGION_FIRST_BYTE        0x10
+#define CHECKSUM_REGION_LAST_BYTE         0x2d
 
+// Following fields are used by SEABIOS
+#define NVRAM_REG_HIGHMEM_LOW             0x5b
+#define NVRAM_REG_HIGHMEM_MID             0x5c
+#define NVRAM_REG_HIGHMEM_HIGH            0x5d
+#define NVRAM_REG_SMPCPUS                 0x5f
+
+#define DEFAULT_BOOTSEQ                   "cd,hd"
 
 struct nvram_internal {
-  nvram_state_t dev_state;
-  uchar_t       thereg;
-  uchar_t       mem_state[NVRAM_REG_MAX];
+    nvram_state_t dev_state;
+    uint8_t       thereg;
+    uint8_t       mem_state[NVRAM_REG_MAX];
+    uint8_t       reg_map[NVRAM_REG_MAX / 8];
+
+    struct vm_device * ide;
+
+    struct v3_vm_info * vm;
+    
+    struct v3_timer   *timer;
+
+    v3_lock_t nvram_lock;
+
+    uint64_t        us;   //microseconds - for clock update - zeroed every second
+    uint64_t        pus;  //microseconds - for periodic interrupt - cleared every period
 };
 
 
+struct rtc_stata {
+    uint8_t        rate   : 4;  // clock rate = 65536Hz / 2 rate (0110=1024 Hz)
+    uint8_t        basis  : 3;  // time base, 010 = 32,768 Hz
+    uint8_t        uip    : 1;  // 1=update in progress
+} __attribute__((__packed__)) __attribute__((__aligned__ (1)))  ;
 
+struct rtc_statb {
+    uint8_t        sum    : 1;  // 1=summer (daylight savings)
+    uint8_t        h24    : 1;  // 1=24h clock
+    uint8_t        dm     : 1;  // 0=date/time is in bcd, 1=binary
+    uint8_t        rec    : 1;  // 1=rectangular signal
+    uint8_t        ui     : 1;  // 1=update interrupt
+    uint8_t        ai     : 1;  // 1=alarm interrupt
+    uint8_t        pi     : 1;  // 1=periodic interrupt
+    uint8_t        set    : 1;  // 1=blocked update
+} __attribute__((__packed__))  __attribute__((__aligned__ (1))) ;
 
+struct rtc_statc {
+    uint8_t        res    : 4;  // reserved
+    uint8_t        uf     : 1;  // 1=source of interrupt is update
+    uint8_t        af     : 1;  // 1=source of interrupt is alarm interrupt
+    uint8_t        pf     : 1;  // 1=source of interrupt is periodic interrupt
+    uint8_t        irq    : 1;  // 1=interrupt requested
+}  __attribute__((__packed__))  __attribute__((__aligned__ (1))) ;
 
-int nvram_reset_device(struct vm_device *dev)
-{
-  struct nvram_internal *data = (struct nvram_internal *) dev->private_data;
+struct rtc_statd {
+    uint8_t        res    : 7;  // reserved
+    uint8_t        val    : 1;  // 1=cmos ram data is OK
+}  __attribute__((__packed__))  __attribute__((__aligned__ (1))) ;
+
+
+
+
+struct bcd_num {
+    uint8_t bot : 4;
+    uint8_t top : 4;
+} __attribute__((packed));;
+
+
+
+static void set_reg_num(struct nvram_internal * nvram, uint8_t reg_num) {
+    int major = (reg_num / 8);
+    int minor = reg_num % 8;
+
+    nvram->reg_map[major] |= (0x1 << minor);
+}
+
+static int is_reg_set(struct nvram_internal * nvram, uint8_t reg_num) {
+    int major = (reg_num / 8);
+    int minor = reg_num % 8;
+    
+    return (nvram->reg_map[major] & (0x1 << minor)) ? 1 : 0;
+}
+
+
+static void set_memory(struct nvram_internal * nvram, uint8_t reg, uint8_t val) {
+    set_reg_num(nvram, reg);
+    nvram->mem_state[reg] = val;
+}
+
+static int get_memory(struct nvram_internal * nvram, uint8_t reg, uint8_t * val) {
+
+    if (!is_reg_set(nvram, reg)) {
+       *val = 0;
+       return -1;
+    }
+
+    *val = nvram->mem_state[reg];
+    return 0;
+}
+
+
+static uint8_t add_to(uint8_t * left, uint8_t * right, uint8_t bcd) {
+    uint8_t temp;
+
+    if (bcd) { 
+       struct bcd_num * bl = (struct bcd_num *)left;
+       struct bcd_num * br = (struct bcd_num *)right;
+       uint8_t carry = 0;
+
+       bl->bot += br->bot;
+       carry = bl->bot / 0xa;
+       bl->bot %= 0xa;
+
+       bl->top += carry + br->top;
+       carry = bl->top / 0xa;
+       bl->top %= 0xa;
+
+       return carry;
+    } else {
+       temp = *left;
+       *left += *right;
+
+       if (*left < temp) { 
+           return 1;
+       } else {
+           return 0;
+       }
+    }
+}
+
+
+static uint8_t days_in_month(uint8_t month, uint8_t bcd) {
+    // This completely ignores Julian / Gregorian stuff right now
+
+    if (bcd) { 
+
+       switch (month) 
+           {
+               case 0x1: //jan
+               case 0x3: //march
+               case 0x5: //may
+               case 0x7: //july
+               case 0x8: //aug
+               case 0x10: //oct
+               case 0x12: //dec
+                   return 0x31;
+                   break;
+               case 0x4: //april
+               case 0x6: //june
+               case 0x9: //sept
+               case 0x11: //nov
+                   return 0x30;
+                   break;
+               case 0x2: //feb
+                   return 0x28;
+                   break;
+               default:
+                   return 0x30;
+           }
+    
+    } else {
+
+       switch (month) 
+           {
+               case 1: //jan
+               case 3: //march
+               case 5: //may
+               case 7: //july
+               case 8: //aug
+               case 10: //oct
+               case 12: //dec
+                   return 31;
+                   break;
+               case 4: //april
+               case 6: //june
+               case 9: //sept
+               case 11: //nov
+                   return 30;
+                   break;
+               case 2: //feb
+                   return 28;
+                   break;
+               default:
+                   return 30;
+           }
+    }
+}
+
+
+static void update_time(struct nvram_internal * data, uint64_t period_us) {
+    struct rtc_stata * stata = (struct rtc_stata *)&((data->mem_state[NVRAM_REG_STAT_A]));
+    struct rtc_statb * statb = (struct rtc_statb *)&((data->mem_state[NVRAM_REG_STAT_B]));
+    struct rtc_statc * statc = (struct rtc_statc *)&((data->mem_state[NVRAM_REG_STAT_C]));
+    //struct rtc_statd *statd = (struct rtc_statd *) &((data->mem_state[NVRAM_REG_STAT_D]));
+    uint8_t * sec      = (uint8_t *)&(data->mem_state[NVRAM_REG_SEC]);
+    uint8_t * min      = (uint8_t *)&(data->mem_state[NVRAM_REG_MIN]);
+    uint8_t * hour     = (uint8_t *)&(data->mem_state[NVRAM_REG_HOUR]);
+    uint8_t * weekday  = (uint8_t *)&(data->mem_state[NVRAM_REG_WEEK_DAY]);
+    uint8_t * monthday = (uint8_t *)&(data->mem_state[NVRAM_REG_MONTH_DAY]);
+    uint8_t * month    = (uint8_t *)&(data->mem_state[NVRAM_REG_MONTH]);
+    uint8_t * year     = (uint8_t *)&(data->mem_state[NVRAM_REG_YEAR]);
+    uint8_t * cent     = (uint8_t *)&(data->mem_state[NVRAM_REG_IBM_CENTURY_BYTE]);
+    uint8_t * cent_ps2 = (uint8_t *)&(data->mem_state[NVRAM_REG_IBM_PS2_CENTURY_BYTE]);
+    uint8_t * seca     = (uint8_t *)&(data->mem_state[NVRAM_REG_SEC_ALARM]);
+    uint8_t * mina     = (uint8_t *)&(data->mem_state[NVRAM_REG_MIN_ALARM]);
+    uint8_t * houra    = (uint8_t *)&(data->mem_state[NVRAM_REG_HOUR_ALARM]);
+    uint8_t hour24;
+
+    uint8_t bcd = (statb->dm == 0);
+    uint8_t carry = 0;
+    uint8_t nextday = 0;
+    uint32_t  periodic_period;
+
+    PrintDebug(VM_NONE, VCORE_NONE, "nvram: update_time by %llu microseocnds\n",period_us);
   
-  data->dev_state = NVRAM_READY;
-  data->thereg=0;
+    // We will set these flags on exit
+    statc->irq = 0;
+    statc->pf = 0;
+    statc->af = 0;
+    statc->uf = 0;
+
+    // We will reset us after one second
+    data->us += period_us;
+    // We will reset pus after one periodic_period
+    data->pus += period_us;
+
+    if (data->us > 1000000) { 
+       carry = 1;
+       carry = add_to(sec, &carry, bcd);
+
+       if (carry) { 
+           PrintError(VM_NONE, VCORE_NONE, "nvram: somehow managed to get a carry in second update\n"); 
+       }
+
+       if ( (bcd && (*sec == 0x60)) || 
+            ((!bcd) && (*sec == 60))) { 
   
-  return 0;
-
+           *sec = 0;
+
+           carry = 1;
+           carry = add_to(min, &carry, bcd);
+           if (carry) { 
+               PrintError(VM_NONE, VCORE_NONE, "nvram: somehow managed to get a carry in minute update\n"); 
+           }
+
+           if ( (bcd && (*min == 0x60)) || 
+                ((!bcd) && (*min == 60))) { 
+
+               *min = 0;
+               hour24 = *hour;
+
+               if (!(statb->h24)) { 
+
+                   if (hour24 & 0x80) { 
+                       hour24 &= 0x8f;
+                       uint8_t temp = ((bcd) ? 0x12 : 12);
+                       add_to(&hour24, &temp, bcd);
+                   }
+               }
+
+               carry = 1;
+               carry = add_to(&hour24, &carry, bcd);
+               if (carry) { 
+                   PrintError(VM_NONE, VCORE_NONE, "nvram: somehow managed to get a carry in hour update\n"); 
+               }
+
+               if ( (bcd && (hour24 == 0x24)) || 
+                    ((!bcd) && (hour24 == 24))) { 
+                   carry = 1;
+                   nextday = 1;
+                   hour24 = 0;
+               } else {
+                   carry = 0;
+               }
+
+
+               if (statb->h24) { 
+                   *hour = hour24;
+               } else {
+                   if ( (bcd && (hour24 < 0x12)) || 
+                        ((!bcd) && (hour24 < 12))) { 
+                       *hour = hour24;
+
+                   } else {
+
+                       if (!bcd) { 
+                           *hour = (hour24 - 12) | 0x80;
+                       } else {
+                           *hour = hour24;
+                           struct bcd_num * n = (struct bcd_num *)hour;
+
+                           if (n->bot < 0x2) { 
+                               n->top--;
+                               n->bot += 0xa;
+                           }
+
+                           n->bot -= 0x2;
+                           n->top -= 0x1;
+                       }
+                   }
+               }
+
+               // now see if we need to carry into the days and further
+               if (nextday) { 
+                   carry = 1;
+                   add_to(weekday, &carry, bcd);
+
+                   *weekday %= 0x7;  // same regardless of bcd
+
+                   if ((*monthday) != days_in_month(*month, bcd)) {
+                       add_to(monthday, &carry, bcd);
+                   } else {
+                       *monthday = 0x1;
+
+                       carry = 1;
+                       add_to(month, &carry, bcd);
+
+                       if ( (bcd && (*month == 0x13)) || 
+                            ((!bcd) && (*month == 13))) { 
+                           *month = 1; // same for both 
+
+                           carry = 1;
+                           carry = add_to(year, &carry, bcd);
+
+                           if ( (bcd && carry) || 
+                                ((!bcd) && (*year == 100))) { 
+                               *year = 0;
+                               carry = 1;
+                               add_to(cent, &carry, bcd);
+                               *cent_ps2 = *cent;
+                           }
+                       }
+                   }
+               }
+           }
+       }
+
+
+       data->us -= 1000000;
+       // OK, now check for the alarm, if it is set to interrupt
+       if (statb->ai) { 
+           if ((*sec == *seca) && (*min == *mina) && (*hour == *houra)) { 
+               statc->af = 1;
+               PrintDebug(VM_NONE, VCORE_NONE, "nvram: interrupt on alarm\n");
+           }
+       }
+    }
+
+    if (statb->pi) { 
+       periodic_period = 1000000 / (65536 / (0x1 << stata->rate));
+       if (data->pus >= periodic_period) { 
+           statc->pf = 1;
+           data->pus -= periodic_period;
+           PrintDebug(VM_NONE, VCORE_NONE, "nvram: interrupt on periodic\n");
+       }
+    }
+
+    if (statb->ui) { 
+       statc->uf = 1;
+       PrintDebug(VM_NONE, VCORE_NONE, "nvram: interrupt on update\n");
+    }
+
+    statc->irq = (statc->pf || statc->af || statc->uf);
+  
+    PrintDebug(VM_NONE, VCORE_NONE, "nvram: time is now: YMDHMS: 0x%x:0x%x:0x%x:0x%x:0x%x,0x%x bcd=%d\n", *year, *month, *monthday, *hour, *min, *sec,bcd);
+  
+    // Interrupt associated VM, if needed
+    if (statc->irq) { 
+       PrintDebug(VM_NONE, VCORE_NONE, "nvram: injecting interrupt\n");
+       v3_raise_irq(data->vm, NVRAM_RTC_IRQ);
+    }
 }
 
-int nvram_init_device(struct vm_device *dev, struct vm_guest *vm)
+
+static void nvram_update_timer(struct guest_info *vm,
+                              ullong_t           cpu_cycles,
+                              ullong_t           cpu_freq,
+                              void              *priv_data)
 {
-  struct nvram_internal *data = (struct nvram_internal *) dev->private_data;
-  memset(data->mem_state,0,NVRAM_REG_MAX);
+    struct nvram_internal *nvram_state = (struct nvram_internal *)priv_data;
+    uint64_t period_us;
 
-  nvram_reset_device(dev);
+    
+    // cpu freq in khz
+    period_us = (1000*cpu_cycles/cpu_freq);
 
-  // hook ports
-  dev_mgr_hook_io(dev->vm, 
-                 dev,
-                 NVRAM_REG_PORT,
-                 DEVICE_EMULATED,
-                 DEVICE_WRITE);
+    update_time(nvram_state,period_us);
+
+}
 
-  dev_mgr_hook_io(dev->vm, 
-                 dev,
-                 NVRAM_DATA_PORT,
-                 DEVICE_EMULATED,
-                 DEVICE_READWRITE);
 
-  return 0;
+static void set_memory_size(struct nvram_internal * nvram, addr_t bytes) {
+    // 1. Conventional Mem: 0-640k in K
+    // 2. Extended Mem: 0-16MB in K
+    // 3. Big Mem: 0-4G in 64K
+    // 4. High Mem: 4G-... in 64K
+
+    // at most 640K of conventional memory
+    {
+       uint16_t memk = 0;
+
+       if (bytes > (640 * 1024)) {
+           memk = 640;
+       } else {
+           memk = bytes / 1024;
+       }
+
+       set_memory(nvram, NVRAM_REG_BASE_MEMORY_HIGH, (memk >> 8) & 0x00ff);
+       set_memory(nvram, NVRAM_REG_BASE_MEMORY_LOW, memk & 0x00ff);
+    }
+
+    // set extended memory - first 1 MB is lost to 640K chunk
+    // extended memory is min(0MB, bytes - 1MB)
+    {
+       uint16_t memk = 0;
+
+       if (bytes >= (1024 * 1024)) {
+           memk = (bytes - (1024 * 1024)) / 1024;
+       }
+       
+       set_memory(nvram, NVRAM_REG_EXT_MEMORY_HIGH, (memk >> 8) & 0x00ff);
+       set_memory(nvram, NVRAM_REG_EXT_MEMORY_LOW, memk & 0x00ff);
+       set_memory(nvram, NVRAM_REG_EXT_MEMORY_2ND_HIGH, (memk >> 8) & 0x00ff);
+       set_memory(nvram, NVRAM_REG_EXT_MEMORY_2ND_LOW, memk & 0x00ff);
+    }
+
+    // Set the extended memory beyond 16 MB in 64k chunks
+    // this is min(0, bytes - 16MB)
+    {
+       uint16_t mem_chunks = 0;
+
+       if (bytes >= (1024 * 1024 * 16)) {
+           mem_chunks = (bytes - (1024 * 1024 * 16)) / (1024 * 64);
+       }
+       
+       set_memory(nvram, NVRAM_REG_AMI_BIG_MEMORY_HIGH, (mem_chunks >> 8) & 0x00ff);
+       set_memory(nvram, NVRAM_REG_AMI_BIG_MEMORY_LOW, mem_chunks & 0x00ff);
+    }
+
+    // Set high (>4GB) memory size
+    {
+
+       uint32_t high_mem_chunks = 0;
+
+       if (bytes >= (1024LL * 1024LL * 1024LL * 4LL)) {
+           high_mem_chunks = (bytes - (1024LL * 1024LL * 1024LL * 4LL))  / (1024 * 64);
+       }
+
+       set_memory(nvram, NVRAM_REG_HIGHMEM_LOW, high_mem_chunks & 0xff);
+       set_memory(nvram, NVRAM_REG_HIGHMEM_MID, (high_mem_chunks >> 8) & 0xff);
+       set_memory(nvram, NVRAM_REG_HIGHMEM_HIGH, (high_mem_chunks >> 16) & 0xff);
+    }
+
+    return;
 }
 
-int nvram_deinit_device(struct vm_device *dev)
-{
 
-  nvram_reset_device(dev);
+
+static void init_harddrives(struct nvram_internal * nvram) {
+    uint8_t hd_data = 0;
+    uint32_t cyls;
+    uint32_t sects;
+    uint32_t heads;
+    int i = 0;
+    int info_base_reg = 0x1b;
+    int type_reg = 0x19;
+
+    // 0x19 == first drive type
+    // 0x1a == second drive type
+
+    // 0x1b == first drive geometry base
+    // 0x24 == second drive geometry base
+
+    // It looks like the BIOS only tracks the disks on the first channel at 0x12?
+    for (i = 0; i < 2; i++) {
+       if (v3_ide_get_geometry(nvram->ide->private_data, 0, i, &cyls, &heads, &sects) == 0) {
+
+           int info_reg = info_base_reg + (i * 9);
+
+           set_memory(nvram, type_reg + i, 0x2f);
+
+           set_memory(nvram, info_reg, cyls & 0xff);
+           set_memory(nvram, info_reg + 1, (cyls >> 8) & 0xff);
+           set_memory(nvram, info_reg + 2, heads & 0xff);
+
+           // Write precomp cylinder (1 and 2)
+           set_memory(nvram, info_reg + 3, 0xff);
+           set_memory(nvram, info_reg + 4, 0xff);
+
+           // harddrive control byte 
+           set_memory(nvram, info_reg + 5, 0xc0 | ((heads > 8) << 3));
+
+           set_memory(nvram, info_reg + 6, cyls & 0xff);
+           set_memory(nvram, info_reg + 7, (cyls >> 8) & 0xff);
+
+           set_memory(nvram, info_reg + 8, sects & 0xff);
+           
+           hd_data |= (0xf0 >> (i * 4));
+       }
+    }
+
+    set_memory(nvram, NVRAM_IBM_HD_DATA, hd_data);
+    
+    {
+#define TRANSLATE_NONE  0x0
+#define TRANSLATE_LBA   0x1
+#define TRANSLATE_LARGE 0x2
+#define TRANSLATE_RECHS 0x3
+       // We're going to do LBA translation for everything...
+       uint8_t trans = 0;
+
+       for (i = 0; i < 4; i++) {
+           int chan_num = i / 2;
+           int drive_num = i % 2;
+           uint32_t tmp[3];
+
+           if (v3_ide_get_geometry(nvram->ide->private_data, chan_num, drive_num, &tmp[0], &tmp[1], &tmp[2]) == 0) {
+               trans |= TRANSLATE_LBA << (i * 2);
+           }
+       }
+
+       set_memory(nvram, NVRAM_IDE_TRANSLATION, trans);
+    }
+}
+
+static uint16_t compute_checksum(struct nvram_internal * nvram) {
+    uint16_t checksum = 0;
+    uint8_t reg = 0;
+    uint8_t val = 0;
+    
+    /* add all fields between the RTC and the checksum fields */
+    for (reg = CHECKSUM_REGION_FIRST_BYTE; reg < CHECKSUM_REGION_LAST_BYTE; reg++) {
+        /* unset fields are considered zero so get_memory can be ignored */
+        get_memory(nvram, reg, &val);
+       checksum += val;
+    }
+               
+    return checksum;
+}
+
+static int init_nvram_state(struct v3_vm_info * vm, struct nvram_internal * nvram, char *bootseq) {
+    uint16_t checksum = 0;
+    uint64_t mem_size=vm->mem_size;
+    uint32_t num_cores=vm->num_cores;
+
+#ifdef V3_CONFIG_HVM
+    mem_size = v3_get_hvm_ros_memsize(vm);
+    num_cores = v3_get_hvm_ros_cores(vm);
+#endif
+
+    memset(nvram->mem_state, 0, NVRAM_REG_MAX);
+    memset(nvram->reg_map, 0, NVRAM_REG_MAX / 8);
+
+    v3_lock_init(&(nvram->nvram_lock));
+
+    //
+    // There are no floppy drives
+    //
+    set_memory(nvram, NVRAM_REG_FLOPPY_TYPE, 0x00);
+
+    //
+    // For old boot sequence style, do non-floppy devices first
+    //
+    set_memory(nvram, NVRAM_REG_BOOTSEQ_OLD, 0x00);
+
+    if (!strcasecmp(bootseq,"cd")) { 
+       // CD only
+       set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_FIRST, 0x03);
+       set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_SECOND, 0x00);
+    } else if (!strcasecmp(bootseq,"cd,hd")) { 
+       // CD, then HD
+       set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_FIRST, 0x23);
+       set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_SECOND, 0x00);
+    } else if (!strcasecmp(bootseq,"hd")) {
+       // HD only
+       set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_FIRST, 0x02);
+       set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_SECOND, 0x00);
+    } else if (!strcasecmp(bootseq,"hd,cd")) { 
+       // HD, then CD
+       set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_FIRST, 0x32);
+       set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_SECOND, 0x00);
+    } else {
+       PrintError(vm,VCORE_NONE,"nvram: unknown boot sequence '%s', setting 'cd,hd'\n",bootseq);
+       // CD, then HD
+       set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_FIRST, 0x23);
+       set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_SECOND, 0x00);
+    }
+
+    // Set equipment byte to note no floppies, vga display, keyboard, math
+    set_memory(nvram, NVRAM_REG_EQUIPMENT_BYTE, 0x2e);
   
-  dev_mgr_unhook_device(dev->vm,dev);
 
-  return 0;
+    // Set the shutdown status gently
+    // soft reset
+    set_memory(nvram, NVRAM_REG_SHUTDOWN_STATUS, 0x0);
+
+
+    // RTC status A
+    // 00100110 = no update in progress, base=32768 Hz, rate = 1024 Hz
+    set_memory(nvram, NVRAM_REG_STAT_A, 0x26); 
+
+    // RTC status B
+    // 00000010 = not setting, no interrupts, blocked rect signal, bcd mode (bit 3 = 0), 24 hour, normal time
+    set_memory(nvram, NVRAM_REG_STAT_B, 0x02); 
+
+
+    // RTC status C
+    // No IRQ requested, result not do to any source
+    set_memory(nvram, NVRAM_REG_STAT_C, 0x00);
+
+    // RTC status D
+    // Battery is OK
+    set_memory(nvram, NVRAM_REG_STAT_D, 0x80);
+
+
+    // january 1, 2008, 00:00:00
+    set_memory(nvram, NVRAM_REG_SEC, 0x00);
+    set_memory(nvram, NVRAM_REG_SEC_ALARM, 0x00);
+    set_memory(nvram, NVRAM_REG_MIN, 0x00);
+    set_memory(nvram, NVRAM_REG_MIN_ALARM, 0x00);
+    set_memory(nvram, NVRAM_REG_HOUR, 0x00);
+    set_memory(nvram, NVRAM_REG_HOUR_ALARM, 0x00);
+
+    set_memory(nvram, NVRAM_REG_MONTH, 0x01);
+    set_memory(nvram, NVRAM_REG_MONTH_DAY, 0x1);
+    set_memory(nvram, NVRAM_REG_WEEK_DAY, 0x1);
+    set_memory(nvram, NVRAM_REG_YEAR, 0x08);
+    set_memory(nvram, NVRAM_REG_IBM_CENTURY_BYTE, 0x20);
+    set_memory(nvram, NVRAM_REG_IBM_PS2_CENTURY_BYTE, 0x20);
+
+    set_memory(nvram, NVRAM_REG_DIAGNOSTIC_STATUS, 0x00);
+    
+    nvram->us = 0;
+    nvram->pus = 0;
+
+
+    set_memory_size(nvram, mem_size);
+    init_harddrives(nvram);
+
+    set_memory(nvram, NVRAM_REG_SMPCPUS, num_cores - 1);
+    
+    /* compute checksum (must follow all assignments here) */
+    checksum = compute_checksum(nvram);
+    set_memory(nvram, NVRAM_REG_CSUM_HIGH, (checksum >> 8) & 0xff);
+    set_memory(nvram, NVRAM_REG_CSUM_LOW, checksum & 0xff);
+
+    
+    
+    nvram->dev_state = NVRAM_READY;
+    nvram->thereg = 0;
+
+    return 0;
 }
 
 
@@ -102,101 +756,171 @@ int nvram_deinit_device(struct vm_device *dev)
 
 
 
-int nvram_start_device(struct vm_device *dev)
-{
-  return 0;
+static int nvram_write_reg_port(struct guest_info * core, uint16_t port,
+                               void * src, uint_t length, void * priv_data) {
+    uint8_t reg;
+    struct nvram_internal * data = priv_data;
+
+    memcpy(&reg,src,1);
+
+    data->thereg = reg & 0x7f;  //discard NMI bit if it's there
+    
+    PrintDebug(core->vm_info, core, "nvram: Writing To NVRAM reg: 0x%x (NMI_disable=%d)\n", data->thereg,reg>>7);
+
+    return 1;
 }
 
+static int nvram_read_data_port(struct guest_info * core, uint16_t port,
+                               void * dst, uint_t length, void * priv_data) {
 
-int nvram_stop_device(struct vm_device *dev)
-{
-  return 0;
+    struct nvram_internal * data = priv_data;
+
+    addr_t irq_state = v3_lock_irqsave(data->nvram_lock);
+
+    if (get_memory(data, data->thereg, (uint8_t *)dst) == -1) {
+       PrintError(core->vm_info, core, "nvram: Register %d (0x%x) Not set - POSSIBLE BUG IN MACHINE INIT - CONTINUING\n", data->thereg, data->thereg);
+
+    } 
+
+    PrintDebug(core->vm_info, core, "nvram: nvram_read_data_port(0x%x)  =  0x%x\n", data->thereg, *(uint8_t *)dst);
+
+    // hack
+    if (data->thereg == NVRAM_REG_STAT_A) { 
+       data->mem_state[data->thereg] ^= 0x80;  // toggle Update in progess
+    }
+
+    v3_unlock_irqrestore(data->nvram_lock, irq_state);
+
+    return 1;
 }
 
 
+static int nvram_write_data_port(struct guest_info * core, uint16_t port,
+                                void * src, uint_t length, void * priv_data) {
 
-int nvram_read_io_port(ushort_t port_read,
-                      void   *address, 
-                      uint_t length,
-                      struct vm_device *dev)
-{
-  struct nvram_internal *data = (struct nvram_internal *) dev->private_data;
-
-  switch (port_read) { 
-  case NVRAM_REG_PORT:
-    // nonsense
-    memset(address,0,length);
-    break;
-  case NVRAM_DATA_PORT:
-    memcpy(address,&(data->mem_state[data->thereg]),1);
-    break;
-  default:
-    //bad
-    return -1;
-  }
-  return 0;
-}
-
-int nvram_write_io_port(ushort_t port_written,
-                       void   *address, 
-                       uint_t length,
-                       struct vm_device *dev)
-{
-  struct nvram_internal *data = (struct nvram_internal *) dev->private_data;
-
-  switch (port_written) { 
-  case NVRAM_REG_PORT:
-    memcpy(&(data->thereg),address,1);
-    break;
-  case NVRAM_DATA_PORT:
-    memcpy(&(data->mem_state[data->thereg]),address,1);
-    break;
-  default:
-    //bad
-    return -1;
-  }
-  return 0;
-}
-
-int nvram_read_mapped_memory(void   *address_read,
-                            void   *address, 
-                            uint_t length,
-                            struct vm_device *dev)
-{
-  return -1;
+    struct nvram_internal * data = priv_data;
+
+    addr_t irq_state = v3_lock_irqsave(data->nvram_lock);
+
+    set_memory(data, data->thereg, *(uint8_t *)src);
+
+    v3_unlock_irqrestore(data->nvram_lock, irq_state);
 
+    PrintDebug(core->vm_info, core, "nvram: nvram_write_data_port(0x%x) = 0x%x\n", 
+              data->thereg, data->mem_state[data->thereg]);
+
+    return 1;
 }
 
-int nvram_write_mapped_memory(void   *address_written,
-                             void   *address, 
-                             uint_t length,
-                             struct vm_device *dev)
-{
-  return -1;
+
+
+
+static int nvram_free(struct nvram_internal * nvram_state) {
+    
+    // unregister host events
+    struct guest_info *info = &(nvram_state->vm->cores[0]);
+
+    if (nvram_state->timer) { 
+       v3_remove_timer(info,nvram_state->timer);
+    }
+
+    v3_lock_deinit(&(nvram_state->nvram_lock));
+
+    V3_Free(nvram_state);
+    return 0;
 }
 
 
-static struct vm_device nvram_template = 
-  { .init_device = nvram_init_device, 
-    .deinit_device = nvram_deinit_device,
-    .reset_device = nvram_reset_device,
-    .start_device = nvram_start_device,
-    .stop_device = nvram_stop_device,
-    .read_io_port = nvram_read_io_port,
-    .write_io_port = nvram_write_io_port,
-    .read_mapped_memory = nvram_read_mapped_memory,
-    .write_mapped_memory= nvram_write_mapped_memory,
-  };
 
+static struct v3_timer_ops timer_ops = {
+    .update_timer = nvram_update_timer,
+};
 
 
-struct vm_device *nvram_create()
-{
-  struct vm_device *device = os_hooks->malloc(sizeof(struct vm_device));
+static struct v3_device_ops dev_ops = {  
+    .free = (int (*)(void *))nvram_free,
+};
+
+
+/*
 
-  *device = nvram_template;
+  <device class="NVRAM" id="nvram">
+     <storage>STORAGE</storage>
+     <bootseq>BOOTSEQ</bootseq>
+  </device>
 
-  device->private_data = os_hooks->malloc(sizeof(struct nvram_internal));
+  STORAGE = the id of the storage controller that will be used to populate
+            the legacy storage device info (e.g., cd, hd the bios knows about)
 
-  return device;
+  BOOTSEQ = the boot sequence desired - note lack of spaces:
+            
+            cd         - first cd only
+            hd         - first hd only
+            cd,hd      - first cd, then first hd
+            hd,cd      - first hd, then first cd
+     
+            The default is cd,hd
+*/
+
+static int nvram_init(struct v3_vm_info * vm, v3_cfg_tree_t * cfg) {
+    struct nvram_internal * nvram_state = NULL;
+    struct vm_device * ide = v3_find_dev(vm, v3_cfg_val(cfg, "storage"));
+    char * dev_id = v3_cfg_val(cfg, "ID");
+    char * bootseq = v3_cfg_val(cfg,"bootseq");
+
+    int ret = 0;
+
+    if (!ide) {
+       PrintError(vm, VCORE_NONE, "nvram: Could not find IDE device\n");
+       return -1;
+    }
+
+    if (!bootseq) { 
+       bootseq=DEFAULT_BOOTSEQ;
+       PrintDebug(vm, VCORE_NONE, "nvram: using default boot sequence %s\n",bootseq);
+    }
+
+    PrintDebug(vm, VCORE_NONE, "nvram: init_device\n");
+    nvram_state = (struct nvram_internal *)V3_Malloc(sizeof(struct nvram_internal) + 1000);
+
+    if (!nvram_state) {
+       PrintError(vm, VCORE_NONE, "Cannot allocate in init\n");
+       return -1;
+    }
+
+    PrintDebug(vm, VCORE_NONE, "nvram: internal at %p\n", (void *)nvram_state);
+
+    nvram_state->ide = ide;
+    nvram_state->vm = vm;
+
+    struct vm_device * dev = v3_add_device(vm, dev_id, &dev_ops, nvram_state);
+
+    if (dev == NULL) {
+       PrintError(vm, VCORE_NONE, "nvram: Could not attach device %s\n", dev_id);
+       V3_Free(nvram_state);
+       return -1;
+    }
+
+    init_nvram_state(vm, nvram_state, bootseq);
+
+    // hook ports
+    ret |= v3_dev_hook_io(dev, NVRAM_REG_PORT, NULL, &nvram_write_reg_port);
+    ret |= v3_dev_hook_io(dev, NVRAM_DATA_PORT, &nvram_read_data_port, &nvram_write_data_port);
+  
+    if (ret != 0) {
+       PrintError(vm, VCORE_NONE, "nvram: Error hooking NVRAM IO ports\n");
+       v3_remove_device(dev);
+       return -1;
+    }
+
+    nvram_state->timer = v3_add_timer(&(vm->cores[0]),&timer_ops,nvram_state);
+
+    if (nvram_state->timer == NULL ) { 
+       v3_remove_device(dev);
+       return -1;
+    }
+
+    return 0;
 }
+
+device_register("NVRAM", nvram_init)