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.


Merge branch 'devel' of palacios@newskysaw.cs.northwestern.edu:/home/palacios/palacio...
[palacios.git] / palacios / src / devices / nvram.c
index 1244f90..e08d5d3 100644 (file)
  */
 
 
-#include <devices/nvram.h>
+#include <palacios/vmm_dev_mgr.h>
 #include <palacios/vmm.h>
 #include <palacios/vmm_types.h>
 
+#include <palacios/vmm_lock.h>
 
-#ifndef DEBUG_NVRAM
+#include <devices/ide.h>
+#include <palacios/vmm_intr.h>
+#include <palacios/vmm_host_events.h>
+#include <palacios/vm_guest.h>
+
+#ifndef CONFIG_DEBUG_NVRAM
 #undef PrintDebug
 #define PrintDebug(fmt, args...)
 #endif
@@ -61,6 +67,7 @@ typedef enum {NVRAM_READY, NVRAM_REG_POSTED} nvram_state_t;
 #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
@@ -92,6 +99,13 @@ struct nvram_internal {
     nvram_state_t dev_state;
     uchar_t       thereg;
     uchar_t       mem_state[NVRAM_REG_MAX];
+    uchar_t       reg_map[NVRAM_REG_MAX / 8];
+
+    struct vm_device * ide;
+
+    struct v3_vm_info * vm;
+
+    v3_lock_t nvram_lock;
 
     uint_t        us;   //microseconds - for clock update - zeroed every second
     uint_t        pus;  //microseconds - for periodic interrupt - cleared every period
@@ -138,6 +152,38 @@ struct bcd_num {
 
 
 
+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 uchar_t add_to(uchar_t * left, uchar_t * right, uchar_t bcd) {
     uchar_t temp;
 
@@ -168,7 +214,7 @@ static uchar_t add_to(uchar_t * left, uchar_t * right, uchar_t bcd) {
 }
 
 
-static uchar_t days_in_month(struct vm_device * dev, uchar_t month, uchar_t bcd) {
+static uchar_t days_in_month(uchar_t month, uchar_t bcd) {
     // This completely ignores Julian / Gregorian stuff right now
 
     if (bcd) { 
@@ -226,8 +272,7 @@ static uchar_t days_in_month(struct vm_device * dev, uchar_t month, uchar_t bcd)
 }
 
 
-static void update_time(struct vm_device * dev, uint_t period_us) {
-    struct nvram_internal * data = (struct nvram_internal *) (dev->private_data);
+static void update_time(struct nvram_internal * data, uint_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]));
@@ -349,7 +394,7 @@ static void update_time(struct vm_device * dev, uint_t period_us) {
 
                    *weekday %= 0x7;  // same regardless of bcd
 
-                   if ((*monthday) != days_in_month(dev, *month, bcd)) {
+                   if ((*monthday) != days_in_month(*month, bcd)) {
                        add_to(monthday, &carry, bcd);
                    } else {
                        *monthday = 0x1;
@@ -408,19 +453,22 @@ static void update_time(struct vm_device * dev, uint_t period_us) {
     // Interrupt associated VM, if needed
     if (statc->irq) { 
        PrintDebug("nvram: injecting interrupt\n");
-       v3_raise_irq(dev->vm, NVRAM_RTC_IRQ);
+       v3_raise_irq(data->vm, NVRAM_RTC_IRQ);
     }
 }
 
 
-static int handle_timer_event(struct guest_info * info, 
+static int handle_timer_event(struct v3_vm_info * vm, 
                              struct v3_timer_event * evt, 
                              void * priv_data) {
 
-    struct vm_device * dev = (struct vm_device *)priv_data;
 
-    if (dev) {
-       update_time(dev, evt->period_us);
+    struct nvram_internal * data = priv_data;
+
+    if (data) {
+       addr_t irq_state = v3_lock_irqsave(data->nvram_lock);
+       update_time(data, evt->period_us);
+       v3_unlock_irqrestore(data->nvram_lock, irq_state);
     }
   
     return 0;
@@ -434,28 +482,32 @@ static void set_memory_size(struct nvram_internal * nvram, addr_t bytes) {
     // 3. Big Mem: 0-4G in 64K
 
     if (bytes > 640 * 1024) {
-       nvram->mem_state[NVRAM_REG_BASE_MEMORY_HIGH] = 0x02;
-       nvram->mem_state[NVRAM_REG_BASE_MEMORY_LOW] = 0x80;
+       set_memory(nvram, NVRAM_REG_BASE_MEMORY_HIGH, 0x02);
+       set_memory(nvram, NVRAM_REG_BASE_MEMORY_LOW, 0x80);
+
+       //      nvram->mem_state[NVRAM_REG_BASE_MEMORY_HIGH] = 0x02;
+       //      nvram->mem_state[NVRAM_REG_BASE_MEMORY_LOW] = 0x80;
     } else {
        uint16_t memk = bytes * 1024;
-       nvram->mem_state[NVRAM_REG_BASE_MEMORY_HIGH] = (memk >> 8) & 0x00ff;
-       nvram->mem_state[NVRAM_REG_BASE_MEMORY_LOW] = memk & 0x00ff;
+       set_memory(nvram, NVRAM_REG_BASE_MEMORY_HIGH, (memk >> 8) & 0x00ff);
+       set_memory(nvram, NVRAM_REG_BASE_MEMORY_LOW, memk & 0x00ff);
 
        return;
     }
 
     if (bytes > (16 * 1024 * 1024)) {
        // Set extended memory to 15 MB
-       nvram->mem_state[NVRAM_REG_EXT_MEMORY_HIGH] = 0x3C;
-       nvram->mem_state[NVRAM_REG_EXT_MEMORY_LOW] = 0x00;
-       nvram->mem_state[NVRAM_REG_EXT_MEMORY_2ND_HIGH]= 0x3C;
-       nvram->mem_state[NVRAM_REG_EXT_MEMORY_2ND_LOW]= 0x00;
+       set_memory(nvram, NVRAM_REG_EXT_MEMORY_HIGH, 0x3C);
+       set_memory(nvram, NVRAM_REG_EXT_MEMORY_LOW, 0x00);
+       set_memory(nvram, NVRAM_REG_EXT_MEMORY_2ND_HIGH, 0x3C);
+       set_memory(nvram, NVRAM_REG_EXT_MEMORY_2ND_LOW, 0x00);
     } else {
        uint16_t memk = bytes * 1024;
-       nvram->mem_state[NVRAM_REG_EXT_MEMORY_HIGH] = (memk >> 8) & 0x00ff;
-       nvram->mem_state[NVRAM_REG_EXT_MEMORY_LOW] = memk & 0x00ff;
-       nvram->mem_state[NVRAM_REG_EXT_MEMORY_2ND_HIGH]= (memk >> 8) & 0x00ff;
-       nvram->mem_state[NVRAM_REG_EXT_MEMORY_2ND_LOW]= memk & 0x00ff;
+
+       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);
 
        return;
     }
@@ -463,88 +515,166 @@ static void set_memory_size(struct nvram_internal * nvram, addr_t bytes) {
     {
        // Set the extended memory beyond 16 MB in 64k chunks
        uint16_t mem_chunks = (bytes - (1024 * 1024 * 16)) / (1024 * 64);
-       nvram->mem_state[NVRAM_REG_AMI_BIG_MEMORY_HIGH] = (mem_chunks >> 8) & 0x00ff;
-       nvram->mem_state[NVRAM_REG_AMI_BIG_MEMORY_LOW] = mem_chunks & 0x00ff;
+
+       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);
     }
 
     return;
 }
 
-static int init_nvram_state(struct vm_device * dev) {
-    struct guest_info * info = dev->vm;
-    struct nvram_internal * nvram_state = (struct nvram_internal *)dev->private_data;
-  
-    memset(nvram_state->mem_state, 0, NVRAM_REG_MAX);
+
+
+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, 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, chan_num, drive_num, &tmp[0], &tmp[1], &tmp[2]) == 0) {
+               trans |= TRANSLATE_LBA << (i * 2);
+           }
+       }
+
+       set_memory(nvram, NVRAM_IDE_TRANSLATION, trans);
+    }
+}
+
+static int init_nvram_state(struct v3_vm_info * vm, struct nvram_internal * nvram) {
+
+    memset(nvram->mem_state, 0, NVRAM_REG_MAX);
+    memset(nvram->reg_map, 0, NVRAM_REG_MAX / 8);
+
+    v3_lock_init(&(nvram->nvram_lock));
 
     //
     // 2 1.44 MB floppy drives
     //
 #if 1
-    nvram_state->mem_state[NVRAM_REG_FLOPPY_TYPE] = 0x44;
+    set_memory(nvram, NVRAM_REG_FLOPPY_TYPE, 0x44);
 #else
-    nvram_state->mem_state[NVRAM_REG_FLOPPY_TYPE] = 0x00;
+    set_memory(nvram, NVRAM_REG_FLOPPY_TYPE, 0x00);
 #endif
 
     //
     // For old boot sequence style, do floppy first
     //
-    nvram_state->mem_state[NVRAM_REG_BOOTSEQ_OLD] = 0x10;
+    set_memory(nvram, NVRAM_REG_BOOTSEQ_OLD, 0x10);
 
 #if 0
     // For new boot sequence style, do floppy, cd, then hd
-    nvram_state->mem_state[NVRAM_REG_BOOTSEQ_NEW_FIRST] = 0x31;
-    nvram_state->mem_state[NVRAM_REG_BOOTSEQ_NEW_SECOND] = 0x20;
+    set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_FIRST, 0x31);
+    set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_SECOND, 0x20);
 #endif
 
     // For new boot sequence style, do cd, hd, floppy
-    nvram_state->mem_state[NVRAM_REG_BOOTSEQ_NEW_FIRST] = 0x23;
-    nvram_state->mem_state[NVRAM_REG_BOOTSEQ_NEW_SECOND] = 0x10;
+    set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_FIRST, 0x23);
+    set_memory(nvram, NVRAM_REG_BOOTSEQ_NEW_SECOND, 0x10);
   
   
     // Set equipment byte to note 2 floppies, vga display, keyboard,math,floppy
-    nvram_state->mem_state[NVRAM_REG_EQUIPMENT_BYTE] = 0x4f;
-    // nvram_state->mem_state[NVRAM_REG_EQUIPMENT_BYTE] = 0xf;
+    set_memory(nvram, NVRAM_REG_EQUIPMENT_BYTE, 0x4f);
+    // set_memory(nvram, NVRAM_REG_EQUIPMENT_BYTE, 0xf);
   
 
-    // This is the harddisk type.... Set accordingly...
-    nvram_state->mem_state[NVRAM_IBM_HD_DATA] = 0x20;
-
     // Set the shutdown status gently
     // soft reset
-    nvram_state->mem_state[NVRAM_REG_SHUTDOWN_STATUS] = 0x0;
+    set_memory(nvram, NVRAM_REG_SHUTDOWN_STATUS, 0x0);
 
 
     // RTC status A
     // 00100110 = no update in progress, base=32768 Hz, rate = 1024 Hz
-    nvram_state->mem_state[NVRAM_REG_STAT_A] = 0x26; 
+    set_memory(nvram, NVRAM_REG_STAT_A, 0x26); 
 
     // RTC status B
     // 00000100 = not setting, no interrupts, blocked rect signal, bcd mode, 24 hour, normal time
-    nvram_state->mem_state[NVRAM_REG_STAT_B] = 0x06; 
+    set_memory(nvram, NVRAM_REG_STAT_B, 0x06); 
 
 
     // RTC status C
     // No IRQ requested, result not do to any source
-    nvram_state->mem_state[NVRAM_REG_STAT_C] = 0x00;
+    set_memory(nvram, NVRAM_REG_STAT_C, 0x00);
 
     // RTC status D
     // Battery is OK
-    nvram_state->mem_state[NVRAM_REG_STAT_D] = 0x80;
+    set_memory(nvram, NVRAM_REG_STAT_D, 0x80);
 
 
     // january 1, 2008, 00:00:00
-    nvram_state->mem_state[NVRAM_REG_MONTH] = 0x1;
-    nvram_state->mem_state[NVRAM_REG_MONTH_DAY] = 0x1;
-    nvram_state->mem_state[NVRAM_REG_WEEK_DAY] = 0x1;
-    nvram_state->mem_state[NVRAM_REG_YEAR] = 0x08;
-
-    nvram_state->us = 0;
-    nvram_state->pus = 0;
-
-    set_memory_size(nvram_state, info->mem_size);
+    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_DIAGNOSTIC_STATUS, 0x00);
+    
+    nvram->us = 0;
+    nvram->pus = 0;
 
-    nvram_state->dev_state = NVRAM_READY;
-    nvram_state->thereg = 0;
+    set_memory_size(nvram, vm->mem_size);
+    init_harddrives(nvram);
+    
+    nvram->dev_state = NVRAM_READY;
+    nvram->thereg = 0;
 
     return 0;
 }
@@ -552,95 +682,68 @@ static int init_nvram_state(struct vm_device * dev) {
 
 
 
-static int nvram_reset_device(struct vm_device * dev) {
-
-    return 0;
-}
-
 
 
+static int nvram_write_reg_port(struct guest_info * core, ushort_t port,
+                               void * src, uint_t length, void * priv_data) {
 
+    struct nvram_internal * data = priv_data;
+    
+    memcpy(&(data->thereg), src, 1);
+    PrintDebug("Writing To NVRAM reg: 0x%x\n", data->thereg);
 
-static int nvram_start_device(struct vm_device * dev) {
-    PrintDebug("nvram: start device\n");
-    return 0;
-}
-
-
-static int nvram_stop_device(struct vm_device * dev) {
-    PrintDebug("nvram: stop device\n");
-    return 0;
+    return 1;
 }
 
+static int nvram_read_data_port(struct guest_info * core, ushort_t port,
+                               void * dst, uint_t length, void * priv_data) {
 
+    struct nvram_internal * data = priv_data;
 
+    addr_t irq_state = v3_lock_irqsave(data->nvram_lock);
 
-static 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);
-    PrintDebug("Writing To NVRAM reg: 0x%x\n", data->thereg);
+    if (get_memory(data, data->thereg, (uint8_t *)dst) == -1) {
+       PrintError("Register %d (0x%x) Not set\n", data->thereg, data->thereg);
 
+       v3_unlock_irqrestore(data->nvram_lock, irq_state);
 
-    return 1;
-}
-
-static 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 -1;
+    }
 
-    PrintDebug("nvram_read_data_port(0x%x)=0x%x\n", data->thereg, data->mem_state[data->thereg]);
+    PrintDebug("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(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);
+static int nvram_write_data_port(struct guest_info * core, ushort_t port,
+                                void * src, uint_t length, void * priv_data) {
 
-    PrintDebug("nvram_write_data_port(0x%x)=0x%x\n", data->thereg, data->mem_state[data->thereg]);
+    struct nvram_internal * data = priv_data;
 
-    return 1;
-}
+    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);
 
-static int nvram_init_device(struct vm_device * dev) {
-    PrintDebug("nvram: init_device\n");
+    PrintDebug("nvram_write_data_port(0x%x) = 0x%x\n", 
+              data->thereg, data->mem_state[data->thereg]);
 
-    init_nvram_state(dev);
+    return 1;
+}
 
-    // hook ports
-    v3_dev_hook_io(dev, NVRAM_REG_PORT, NULL, &nvram_write_reg_port);
-    v3_dev_hook_io(dev, NVRAM_DATA_PORT, &nvram_read_data_port, &nvram_write_data_port);
-  
-    v3_hook_host_event(dev->vm, HOST_TIMER_EVT, V3_HOST_EVENT_HANDLER(handle_timer_event), dev);
 
-    return 0;
-}
 
-static int nvram_deinit_device(struct vm_device * dev) {
-    v3_dev_unhook_io(dev, NVRAM_REG_PORT);
-    v3_dev_unhook_io(dev, NVRAM_DATA_PORT);
 
-    nvram_reset_device(dev);
+static int nvram_free(struct vm_device * dev) {
     return 0;
 }
 
@@ -648,25 +751,49 @@ static int nvram_deinit_device(struct vm_device * dev) {
 
 
 
-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,
+static struct v3_device_ops dev_ops = {  
+    .free = nvram_free,
 };
 
 
 
 
-struct vm_device * v3_create_nvram() {
+
+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");
 
+    if (!ide) {
+       PrintError("Could not find IDE device\n");
+       return -1;
+    }
+
+    PrintDebug("nvram: init_device\n");
     nvram_state = (struct nvram_internal *)V3_Malloc(sizeof(struct nvram_internal) + 1000);
 
     PrintDebug("nvram: internal at %p\n", (void *)nvram_state);
 
-    struct vm_device * device = v3_create_device("NVRAM", &dev_ops, nvram_state);
+    nvram_state->ide = ide;
+    nvram_state->vm = vm;
 
-    return device;
+    struct vm_device * dev = v3_allocate_device(dev_id, &dev_ops, nvram_state);
+
+
+    if (v3_attach_device(vm, dev) == -1) {
+       PrintError("Could not attach device %s\n", dev_id);
+       return -1;
+    }
+
+    init_nvram_state(vm, nvram_state);
+
+    // hook ports
+    v3_dev_hook_io(dev, NVRAM_REG_PORT, NULL, &nvram_write_reg_port);
+    v3_dev_hook_io(dev, NVRAM_DATA_PORT, &nvram_read_data_port, &nvram_write_data_port);
+  
+    v3_hook_host_event(vm, HOST_TIMER_EVT, V3_HOST_EVENT_HANDLER(handle_timer_event), nvram_state);
+
+    return 0;
 }
+
+device_register("NVRAM", nvram_init)