diff --git a/exosphere/src/bootconfig.c b/exosphere/src/bootconfig.c
index dd2cfd870..afa1f7e20 100644
--- a/exosphere/src/bootconfig.c
+++ b/exosphere/src/bootconfig.c
@@ -138,9 +138,9 @@ void bootconfig_get_package2_hash_for_recovery(uint64_t *out_hash) {
 }
 
 bool bootconfig_is_recovery_boot(void) {
-    return (g_boot_reason.is_recovery_boot != 0);
+    return ((g_boot_reason.bootloader_attribute & 0x01) != 0);
 }
 
 uint64_t bootconfig_get_boot_reason(void) {
-    return ((uint64_t)g_boot_reason.boot_reason_high << 24) | (g_boot_reason.boot_reason_low & 0xFFFFFF);
+    return ((uint64_t)g_boot_reason.boot_reason_state << 24) | (g_boot_reason.boot_reason_value & 0xFFFFFF);
 }
diff --git a/exosphere/src/bootconfig.h b/exosphere/src/bootconfig.h
index 823323a03..e2e410ade 100644
--- a/exosphere/src/bootconfig.h
+++ b/exosphere/src/bootconfig.h
@@ -34,11 +34,12 @@ static inline bootconfig_t *get_loaded_bootconfig(void) {
 }
 
 typedef struct {
-    uint64_t _0x00;
-    uint32_t _0x08;
-    uint32_t is_recovery_boot;
-    uint32_t boot_reason_low;
-    uint32_t boot_reason_high;
+    uint32_t bootloader_version;
+    uint32_t bootloader_start_block;
+    uint32_t bootloader_start_page;
+    uint32_t bootloader_attribute;
+    uint32_t boot_reason_value;
+    uint32_t boot_reason_state;
 } boot_reason_t;
 
 void bootconfig_load_and_verify(const bootconfig_t *bootconfig);
diff --git a/fusee/fusee-primary/src/btn.c b/fusee/fusee-primary/src/btn.c
index bffc8e79d..942d27be6 100644
--- a/fusee/fusee-primary/src/btn.c
+++ b/fusee/fusee-primary/src/btn.c
@@ -16,7 +16,7 @@ uint32_t btn_read()
         res |= BTN_VOL_UP;
     
     uint32_t val = 0;
-    if (i2c_query(4, 0x3C, 0x15, &val, 1))
+    if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, 0x15, &val, 1))
     {
         if (val & 0x4)
             res |= BTN_POWER;
diff --git a/fusee/fusee-primary/src/di.c b/fusee/fusee-primary/src/di.c
index e22257465..f46310eb8 100644
--- a/fusee/fusee-primary/src/di.c
+++ b/fusee/fusee-primary/src/di.c
@@ -36,9 +36,9 @@ void display_init()
     
     /* Power on. */
     uint8_t val = 0xD0;
-    i2c_send(4, 0x3C, MAX77620_REG_LDO0_CFG, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_LDO0_CFG, &val, 1);
     val = 0x09;
-    i2c_send(4, 0x3C, MAX77620_REG_GPIO7, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_GPIO7, &val, 1);
     
     /* Enable MIPI CAL, DSI, DISP1, HOST1X, UART_FST_MIPI_CAL, DSIA LP clocks. */
     car->rst_dev_h_clr = 0x1010000;
diff --git a/fusee/fusee-primary/src/hwinit.c b/fusee/fusee-primary/src/hwinit.c
index 903b750bd..929136d38 100644
--- a/fusee/fusee-primary/src/hwinit.c
+++ b/fusee/fusee-primary/src/hwinit.c
@@ -203,33 +203,33 @@ void nx_hwinit()
     clkrst_reboot(CARDEVICE_UNK);
 
     /* Initialize I2C1 and I2C5. */
-    i2c_init(0);
-    i2c_init(4);
+    i2c_init(I2C_1);
+    i2c_init(I2C_5);
     
     uint8_t val = 0x40;
-    i2c_send(4, 0x3C, MAX77620_REG_CNFGBBC, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_CNFGBBC, &val, 1);
     val = 0x78;
-    i2c_send(4, 0x3C, MAX77620_REG_ONOFFCNFG1, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_ONOFFCNFG1, &val, 1);
 
     val = 0x38;
-    i2c_send(4, 0x3C, MAX77620_REG_FPS_CFG0, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_FPS_CFG0, &val, 1);
     val = 0x3A;
-    i2c_send(4, 0x3C, MAX77620_REG_FPS_CFG1, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_FPS_CFG1, &val, 1);
     val = 0x38;
-    i2c_send(4, 0x3C, MAX77620_REG_FPS_CFG2, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_FPS_CFG2, &val, 1);
     val = 0xF;
-    i2c_send(4, 0x3C, MAX77620_REG_FPS_LDO4, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_FPS_LDO4, &val, 1);
     val = 0xC7;
-    i2c_send(4, 0x3C, MAX77620_REG_FPS_LDO8, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_FPS_LDO8, &val, 1);
     val = 0x4F;
-    i2c_send(4, 0x3C, MAX77620_REG_FPS_SD0, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_FPS_SD0, &val, 1);
     val = 0x29;
-    i2c_send(4, 0x3C, MAX77620_REG_FPS_SD1, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_FPS_SD1, &val, 1);
     val = 0x1B;
-    i2c_send(4, 0x3C, MAX77620_REG_FPS_SD3, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_FPS_SD3, &val, 1);
 
     val = 42;       /* 42 = (1125000 - 600000) / 12500 -> 1.125V */
-    i2c_send(4, 0x3C, MAX77620_REG_SD0, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_SD0, &val, 1);
 
     /* Configure and lock PMC scratch registers. */
     config_pmc_scratch();
diff --git a/fusee/fusee-primary/src/i2c.c b/fusee/fusee-primary/src/i2c.c
index a98d7fa6e..028ba56e8 100644
--- a/fusee/fusee-primary/src/i2c.c
+++ b/fusee/fusee-primary/src/i2c.c
@@ -43,16 +43,16 @@ void i2c_init(unsigned int id) {
 void i2c_send_pmic_cpu_shutdown_cmd(void) {
     uint32_t val = 0;
     /* PMIC == Device 4:3C. */
-    i2c_query(4, 0x3C, 0x41, &val, 1);
+    i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, 0x41, &val, 1);
     val |= 4;
-    i2c_send(4, 0x3C, 0x41, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, 0x41, &val, 1);
 }
 
 /* Queries the value of TI charger bit over I2C. */
 bool i2c_query_ti_charger_bit_7(void) {
     uint32_t val = 0;
     /* TI Charger = Device 0:6B. */
-    i2c_query(0, 0x6B, 0, &val, 1);
+    i2c_query(I2C_1, BQ24193_I2C_ADDR, 0, &val, 1);
     return (val & 0x80) != 0;
 }
 
@@ -60,34 +60,34 @@ bool i2c_query_ti_charger_bit_7(void) {
 void i2c_clear_ti_charger_bit_7(void) {
     uint32_t val = 0;
     /* TI Charger = Device 0:6B. */
-    i2c_query(0, 0x6B, 0, &val, 1);
+    i2c_query(I2C_1, BQ24193_I2C_ADDR, 0, &val, 1);
     val &= 0x7F;
-    i2c_send(0, 0x6B, 0, &val, 1);
+    i2c_send(I2C_1, BQ24193_I2C_ADDR, 0, &val, 1);
 }
 
 /* Sets TI charger bit over I2C. */
 void i2c_set_ti_charger_bit_7(void) {
     uint32_t val = 0;
     /* TI Charger = Device 0:6B. */
-    i2c_query(0, 0x6B, 0, &val, 1);
+    i2c_query(I2C_1, BQ24193_I2C_ADDR, 0, &val, 1);
     val |= 0x80;
-    i2c_send(0, 0x6B, 0, &val, 1);
+    i2c_send(I2C_1, BQ24193_I2C_ADDR, 0, &val, 1);
 }
 
 /* Get registers pointer based on I2C ID. */
 volatile tegra_i2c_t *i2c_get_registers_from_id(unsigned int id) {
     switch (id) {
-        case 0:
+        case I2C_1:
             return I2C1_REGS;
-        case 1:
+        case I2C_2:
             return I2C2_REGS;
-        case 2:
+        case I2C_3:
             return I2C3_REGS;
-        case 3:
+        case I2C_4:
             return I2C4_REGS;
-        case 4:
+        case I2C_5:
             return I2C5_REGS;
-        case 5:
+        case I2C_6:
             return I2C6_REGS;
         default:
             generic_panic();
diff --git a/fusee/fusee-primary/src/i2c.h b/fusee/fusee-primary/src/i2c.h
index e07ed3349..8b0acbd35 100644
--- a/fusee/fusee-primary/src/i2c.h
+++ b/fusee/fusee-primary/src/i2c.h
@@ -8,6 +8,20 @@
 #define I2C234_BASE 0x7000C000
 #define I2C56_BASE 0x7000D000
 
+#define I2C_1 0
+#define I2C_2 1
+#define I2C_3 2
+#define I2C_4 3
+#define I2C_5 4
+#define I2C_6 5
+
+#define MAX77621_CPU_I2C_ADDR       0x1B
+#define MAX77621_GPU_I2C_ADDR       0x1C
+#define MAX17050_I2C_ADDR           0x36
+#define MAX77620_PWR_I2C_ADDR       0x3C
+#define MAX77620_RTC_I2C_ADDR       0x68
+#define BQ24193_I2C_ADDR            0x6B
+
 typedef struct {
     uint32_t I2C_I2C_CNFG_0;
     uint32_t I2C_I2C_CMD_ADDR0_0;
diff --git a/fusee/fusee-primary/src/max77620.h b/fusee/fusee-primary/src/max77620.h
index ad22a06b5..ab90f2b8e 100644
--- a/fusee/fusee-primary/src/max77620.h
+++ b/fusee/fusee-primary/src/max77620.h
@@ -11,6 +11,36 @@
 #ifndef _MFD_MAX77620_H_
 #define _MFD_MAX77620_H_
 
+/* RTC Registers */
+#define MAX77620_REG_RTCINT     0x00
+#define MAX77620_REG_RTCINTM        0x01
+#define MAX77620_REG_RTCCNTLM       0x02
+#define MAX77620_REG_RTCCNTL        0x03
+#define MAX77620_REG_RTCUPDATE0     0x04
+#define MAX77620_REG_RTCUPDATE1     0x05
+#define MAX77620_REG_RTCSMPL        0x06
+#define MAX77620_REG_RTCSEC     0x07
+#define MAX77620_REG_RTCMIN     0x08
+#define MAX77620_REG_RTCHOUR        0x09
+#define MAX77620_REG_RTCDOW     0x0A
+#define MAX77620_REG_RTCMONTH       0x0B
+#define MAX77620_REG_RTCYEAR        0x0C
+#define MAX77620_REG_RTCDOM     0x0D
+#define MAX77620_REG_RTCSECA1       0x0E
+#define MAX77620_REG_RTCMINA1       0x0F
+#define MAX77620_REG_RTCHOURA1      0x10
+#define MAX77620_REG_RTCDOWA1       0x11
+#define MAX77620_REG_RTCMONTHA1     0x12
+#define MAX77620_REG_RTCYEARA1      0x13
+#define MAX77620_REG_RTCDOMA1       0x14
+#define MAX77620_REG_RTCSECA2       0x15
+#define MAX77620_REG_RTCMINA2       0x16
+#define MAX77620_REG_RTCHOURA2      0x17
+#define MAX77620_REG_RTCDOWA2       0x18
+#define MAX77620_REG_RTCMONTHA2     0x19
+#define MAX77620_REG_RTCYEARA2      0x1A
+#define MAX77620_REG_RTCDOMA2       0x1B
+
 /* GLOBAL, PMIC, GPIO, FPS, ONOFFC, CID Registers */
 #define MAX77620_REG_CNFGGLBL1          0x00
 #define MAX77620_REG_CNFGGLBL2          0x01
diff --git a/fusee/fusee-primary/src/max7762x.c b/fusee/fusee-primary/src/max7762x.c
index 419a13bce..da20eb7b9 100644
--- a/fusee/fusee-primary/src/max7762x.c
+++ b/fusee/fusee-primary/src/max7762x.c
@@ -55,11 +55,11 @@ int max77620_regulator_get_status(uint32_t id)
     uint8_t val = 0;
 
     if (reg->type == REGULATOR_SD) {
-        if (i2c_query(4, 0x3C, MAX77620_REG_STATSD, &val, 1))
+        if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_STATSD, &val, 1))
             return (val & reg->status_mask) ? 0 : 1;
     }
     
-    if (i2c_query(4, 0x3C, reg->cfg_addr, &val, 1))
+    if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, reg->cfg_addr, &val, 1))
         return (val & 8) ? 0 : 1;
     
     return 0;
@@ -73,7 +73,7 @@ int max77620_regulator_config_fps(uint32_t id)
     const max77620_regulator_t *reg = &_pmic_regulators[id];
     uint8_t val = ((reg->fps_src << 6) | (reg->pu_period << 3) | (reg->pd_period));
 
-    if (i2c_send(4, 0x3C, reg->fps_addr, &val, 1)) {
+    if (i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, reg->fps_addr, &val, 1)) {
         return 1;
     }
 
@@ -93,11 +93,11 @@ int max77620_regulator_set_voltage(uint32_t id, uint32_t mv)
     uint32_t mult = (mv + reg->mv_step - 1 - reg->mv_min) / reg->mv_step;
     uint8_t val = 0;
     
-    if (i2c_query(4, 0x3C, reg->volt_addr, &val, 1))
+    if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, reg->volt_addr, &val, 1))
     {
         val = ((val & ~reg->volt_mask) | (mult & reg->volt_mask));
         
-        if (i2c_send(4, 0x3C, reg->volt_addr, &val, 1))
+        if (i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, reg->volt_addr, &val, 1))
         {
             udelay(1000);
             return 1;
@@ -117,14 +117,14 @@ int max77620_regulator_enable(uint32_t id, int enable)
     uint32_t addr = (reg->type == REGULATOR_SD) ? reg->cfg_addr : reg->volt_addr;
     uint8_t val = 0;
     
-    if (i2c_query(4, 0x3C, addr, &val, 1))
+    if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, addr, &val, 1))
     {
         if (enable)
             val = ((val & ~reg->enable_mask) | ((3 << reg->enable_shift) & reg->enable_mask));
         else
             val &= ~reg->enable_mask;
         
-        if (i2c_send(4, 0x3C, addr, &val, 1))
+        if (i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, addr, &val, 1))
         {
             udelay(1000);
             return 1;
@@ -139,7 +139,7 @@ void max77620_config_default()
     for (uint32_t i = 1; i <= REGULATOR_MAX; i++)
     {
         uint8_t val = 0;
-        if (i2c_query(4, 0x3C, MAX77620_REG_CID4, &val, 1))
+        if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_CID4, &val, 1))
         {
             max77620_regulator_config_fps(i);
             max77620_regulator_set_voltage(i, _pmic_regulators[i].mv_default);
@@ -151,11 +151,11 @@ void max77620_config_default()
     }
     
     uint8_t val = 4;
-    i2c_send(4, 0x3C, MAX77620_REG_SD_CFG2, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_SD_CFG2, &val, 1);
 }
 
 void max77620_low_battery_monitor_config()
 {
     uint8_t val = (MAX77620_CNFGGLBL1_LBDAC_EN | MAX77620_CNFGGLBL1_LBHYST_N | MAX77620_CNFGGLBL1_LBDAC_N);
-    i2c_send(4, 0x3C, MAX77620_REG_CNFGGLBL1, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_CNFGGLBL1, &val, 1);
 }
diff --git a/fusee/fusee-primary/src/sdram.c b/fusee/fusee-primary/src/sdram.c
index eb941f235..135833eea 100644
--- a/fusee/fusee-primary/src/sdram.c
+++ b/fusee/fusee-primary/src/sdram.c
@@ -542,9 +542,9 @@ void sdram_init()
     const sdram_params_t *params = (const sdram_params_t *)sdram_get_params();
 
     uint8_t val = 5;
-    i2c_send(4, 0x3C, MAX77620_REG_SD_CFG2, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_SD_CFG2, &val, 1);
     val = 40;   /* 40 = (1000 * 1100 - 600000) / 12500 -> 1.1V */
-    i2c_send(4, 0x3C, MAX77620_REG_SD1, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_SD1, &val, 1);
 
     pmc->vddp_sel = params->pmc_vddp_sel;
     udelay(params->pmc_vddp_sel_wait);
diff --git a/fusee/fusee-secondary/src/btn.c b/fusee/fusee-secondary/src/btn.c
index bffc8e79d..942d27be6 100644
--- a/fusee/fusee-secondary/src/btn.c
+++ b/fusee/fusee-secondary/src/btn.c
@@ -16,7 +16,7 @@ uint32_t btn_read()
         res |= BTN_VOL_UP;
     
     uint32_t val = 0;
-    if (i2c_query(4, 0x3C, 0x15, &val, 1))
+    if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, 0x15, &val, 1))
     {
         if (val & 0x4)
             res |= BTN_POWER;
diff --git a/fusee/fusee-secondary/src/cluster.c b/fusee/fusee-secondary/src/cluster.c
index bceaf7d73..b0c884670 100644
--- a/fusee/fusee-secondary/src/cluster.c
+++ b/fusee/fusee-secondary/src/cluster.c
@@ -12,22 +12,22 @@
 void _cluster_enable_power()
 {
     uint8_t val = 0;
-    i2c_query(4, 0x3C, MAX77620_REG_AME_GPIO, &val, 1);
+    i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_AME_GPIO, &val, 1);
     
     val &= 0xDF;
-    i2c_send(4, 0x3C, MAX77620_REG_AME_GPIO, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_AME_GPIO, &val, 1);
     val = 0x09;
-    i2c_send(4, 0x3C, MAX77620_REG_GPIO5, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_GPIO5, &val, 1);
     
     /* Enable power. */
     val = 0x20;
-    i2c_send(4, 0x1B, MAX77620_REG_CNFGGLBL3, &val, 1);
+    i2c_send(I2C_5, MAX77621_CPU_I2C_ADDR, 0x02, &val, 1);
     val = 0x8D;
-    i2c_send(4, 0x1B, MAX77620_REG_CNFG1_32K, &val, 1);
+    i2c_send(I2C_5, MAX77621_CPU_I2C_ADDR, 0x03, &val, 1);
     val = 0xB7;
-    i2c_send(4, 0x1B, MAX77620_REG_CNFGGLBL1, &val, 1);
+    i2c_send(I2C_5, MAX77621_CPU_I2C_ADDR, 0x00, &val, 1);
     val = 0xB7;
-    i2c_send(4, 0x1B, MAX77620_REG_CNFGGLBL2, &val, 1);
+    i2c_send(I2C_5, MAX77621_CPU_I2C_ADDR, 0x01, &val, 1);
 }
 
 int _cluster_pmc_enable_partition(uint32_t part, uint32_t toggle)
diff --git a/fusee/fusee-secondary/src/di.c b/fusee/fusee-secondary/src/di.c
index e22257465..f46310eb8 100644
--- a/fusee/fusee-secondary/src/di.c
+++ b/fusee/fusee-secondary/src/di.c
@@ -36,9 +36,9 @@ void display_init()
     
     /* Power on. */
     uint8_t val = 0xD0;
-    i2c_send(4, 0x3C, MAX77620_REG_LDO0_CFG, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_LDO0_CFG, &val, 1);
     val = 0x09;
-    i2c_send(4, 0x3C, MAX77620_REG_GPIO7, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_GPIO7, &val, 1);
     
     /* Enable MIPI CAL, DSI, DISP1, HOST1X, UART_FST_MIPI_CAL, DSIA LP clocks. */
     car->rst_dev_h_clr = 0x1010000;
diff --git a/fusee/fusee-secondary/src/i2c.c b/fusee/fusee-secondary/src/i2c.c
index a98d7fa6e..028ba56e8 100644
--- a/fusee/fusee-secondary/src/i2c.c
+++ b/fusee/fusee-secondary/src/i2c.c
@@ -43,16 +43,16 @@ void i2c_init(unsigned int id) {
 void i2c_send_pmic_cpu_shutdown_cmd(void) {
     uint32_t val = 0;
     /* PMIC == Device 4:3C. */
-    i2c_query(4, 0x3C, 0x41, &val, 1);
+    i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, 0x41, &val, 1);
     val |= 4;
-    i2c_send(4, 0x3C, 0x41, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, 0x41, &val, 1);
 }
 
 /* Queries the value of TI charger bit over I2C. */
 bool i2c_query_ti_charger_bit_7(void) {
     uint32_t val = 0;
     /* TI Charger = Device 0:6B. */
-    i2c_query(0, 0x6B, 0, &val, 1);
+    i2c_query(I2C_1, BQ24193_I2C_ADDR, 0, &val, 1);
     return (val & 0x80) != 0;
 }
 
@@ -60,34 +60,34 @@ bool i2c_query_ti_charger_bit_7(void) {
 void i2c_clear_ti_charger_bit_7(void) {
     uint32_t val = 0;
     /* TI Charger = Device 0:6B. */
-    i2c_query(0, 0x6B, 0, &val, 1);
+    i2c_query(I2C_1, BQ24193_I2C_ADDR, 0, &val, 1);
     val &= 0x7F;
-    i2c_send(0, 0x6B, 0, &val, 1);
+    i2c_send(I2C_1, BQ24193_I2C_ADDR, 0, &val, 1);
 }
 
 /* Sets TI charger bit over I2C. */
 void i2c_set_ti_charger_bit_7(void) {
     uint32_t val = 0;
     /* TI Charger = Device 0:6B. */
-    i2c_query(0, 0x6B, 0, &val, 1);
+    i2c_query(I2C_1, BQ24193_I2C_ADDR, 0, &val, 1);
     val |= 0x80;
-    i2c_send(0, 0x6B, 0, &val, 1);
+    i2c_send(I2C_1, BQ24193_I2C_ADDR, 0, &val, 1);
 }
 
 /* Get registers pointer based on I2C ID. */
 volatile tegra_i2c_t *i2c_get_registers_from_id(unsigned int id) {
     switch (id) {
-        case 0:
+        case I2C_1:
             return I2C1_REGS;
-        case 1:
+        case I2C_2:
             return I2C2_REGS;
-        case 2:
+        case I2C_3:
             return I2C3_REGS;
-        case 3:
+        case I2C_4:
             return I2C4_REGS;
-        case 4:
+        case I2C_5:
             return I2C5_REGS;
-        case 5:
+        case I2C_6:
             return I2C6_REGS;
         default:
             generic_panic();
diff --git a/fusee/fusee-secondary/src/i2c.h b/fusee/fusee-secondary/src/i2c.h
index e07ed3349..8b0acbd35 100644
--- a/fusee/fusee-secondary/src/i2c.h
+++ b/fusee/fusee-secondary/src/i2c.h
@@ -8,6 +8,20 @@
 #define I2C234_BASE 0x7000C000
 #define I2C56_BASE 0x7000D000
 
+#define I2C_1 0
+#define I2C_2 1
+#define I2C_3 2
+#define I2C_4 3
+#define I2C_5 4
+#define I2C_6 5
+
+#define MAX77621_CPU_I2C_ADDR       0x1B
+#define MAX77621_GPU_I2C_ADDR       0x1C
+#define MAX17050_I2C_ADDR           0x36
+#define MAX77620_PWR_I2C_ADDR       0x3C
+#define MAX77620_RTC_I2C_ADDR       0x68
+#define BQ24193_I2C_ADDR            0x6B
+
 typedef struct {
     uint32_t I2C_I2C_CNFG_0;
     uint32_t I2C_I2C_CMD_ADDR0_0;
diff --git a/fusee/fusee-secondary/src/max77620.h b/fusee/fusee-secondary/src/max77620.h
index ad22a06b5..ab90f2b8e 100644
--- a/fusee/fusee-secondary/src/max77620.h
+++ b/fusee/fusee-secondary/src/max77620.h
@@ -11,6 +11,36 @@
 #ifndef _MFD_MAX77620_H_
 #define _MFD_MAX77620_H_
 
+/* RTC Registers */
+#define MAX77620_REG_RTCINT     0x00
+#define MAX77620_REG_RTCINTM        0x01
+#define MAX77620_REG_RTCCNTLM       0x02
+#define MAX77620_REG_RTCCNTL        0x03
+#define MAX77620_REG_RTCUPDATE0     0x04
+#define MAX77620_REG_RTCUPDATE1     0x05
+#define MAX77620_REG_RTCSMPL        0x06
+#define MAX77620_REG_RTCSEC     0x07
+#define MAX77620_REG_RTCMIN     0x08
+#define MAX77620_REG_RTCHOUR        0x09
+#define MAX77620_REG_RTCDOW     0x0A
+#define MAX77620_REG_RTCMONTH       0x0B
+#define MAX77620_REG_RTCYEAR        0x0C
+#define MAX77620_REG_RTCDOM     0x0D
+#define MAX77620_REG_RTCSECA1       0x0E
+#define MAX77620_REG_RTCMINA1       0x0F
+#define MAX77620_REG_RTCHOURA1      0x10
+#define MAX77620_REG_RTCDOWA1       0x11
+#define MAX77620_REG_RTCMONTHA1     0x12
+#define MAX77620_REG_RTCYEARA1      0x13
+#define MAX77620_REG_RTCDOMA1       0x14
+#define MAX77620_REG_RTCSECA2       0x15
+#define MAX77620_REG_RTCMINA2       0x16
+#define MAX77620_REG_RTCHOURA2      0x17
+#define MAX77620_REG_RTCDOWA2       0x18
+#define MAX77620_REG_RTCMONTHA2     0x19
+#define MAX77620_REG_RTCYEARA2      0x1A
+#define MAX77620_REG_RTCDOMA2       0x1B
+
 /* GLOBAL, PMIC, GPIO, FPS, ONOFFC, CID Registers */
 #define MAX77620_REG_CNFGGLBL1          0x00
 #define MAX77620_REG_CNFGGLBL2          0x01
diff --git a/fusee/fusee-secondary/src/max7762x.c b/fusee/fusee-secondary/src/max7762x.c
index 419a13bce..da20eb7b9 100644
--- a/fusee/fusee-secondary/src/max7762x.c
+++ b/fusee/fusee-secondary/src/max7762x.c
@@ -55,11 +55,11 @@ int max77620_regulator_get_status(uint32_t id)
     uint8_t val = 0;
 
     if (reg->type == REGULATOR_SD) {
-        if (i2c_query(4, 0x3C, MAX77620_REG_STATSD, &val, 1))
+        if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_STATSD, &val, 1))
             return (val & reg->status_mask) ? 0 : 1;
     }
     
-    if (i2c_query(4, 0x3C, reg->cfg_addr, &val, 1))
+    if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, reg->cfg_addr, &val, 1))
         return (val & 8) ? 0 : 1;
     
     return 0;
@@ -73,7 +73,7 @@ int max77620_regulator_config_fps(uint32_t id)
     const max77620_regulator_t *reg = &_pmic_regulators[id];
     uint8_t val = ((reg->fps_src << 6) | (reg->pu_period << 3) | (reg->pd_period));
 
-    if (i2c_send(4, 0x3C, reg->fps_addr, &val, 1)) {
+    if (i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, reg->fps_addr, &val, 1)) {
         return 1;
     }
 
@@ -93,11 +93,11 @@ int max77620_regulator_set_voltage(uint32_t id, uint32_t mv)
     uint32_t mult = (mv + reg->mv_step - 1 - reg->mv_min) / reg->mv_step;
     uint8_t val = 0;
     
-    if (i2c_query(4, 0x3C, reg->volt_addr, &val, 1))
+    if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, reg->volt_addr, &val, 1))
     {
         val = ((val & ~reg->volt_mask) | (mult & reg->volt_mask));
         
-        if (i2c_send(4, 0x3C, reg->volt_addr, &val, 1))
+        if (i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, reg->volt_addr, &val, 1))
         {
             udelay(1000);
             return 1;
@@ -117,14 +117,14 @@ int max77620_regulator_enable(uint32_t id, int enable)
     uint32_t addr = (reg->type == REGULATOR_SD) ? reg->cfg_addr : reg->volt_addr;
     uint8_t val = 0;
     
-    if (i2c_query(4, 0x3C, addr, &val, 1))
+    if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, addr, &val, 1))
     {
         if (enable)
             val = ((val & ~reg->enable_mask) | ((3 << reg->enable_shift) & reg->enable_mask));
         else
             val &= ~reg->enable_mask;
         
-        if (i2c_send(4, 0x3C, addr, &val, 1))
+        if (i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, addr, &val, 1))
         {
             udelay(1000);
             return 1;
@@ -139,7 +139,7 @@ void max77620_config_default()
     for (uint32_t i = 1; i <= REGULATOR_MAX; i++)
     {
         uint8_t val = 0;
-        if (i2c_query(4, 0x3C, MAX77620_REG_CID4, &val, 1))
+        if (i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_CID4, &val, 1))
         {
             max77620_regulator_config_fps(i);
             max77620_regulator_set_voltage(i, _pmic_regulators[i].mv_default);
@@ -151,11 +151,11 @@ void max77620_config_default()
     }
     
     uint8_t val = 4;
-    i2c_send(4, 0x3C, MAX77620_REG_SD_CFG2, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_SD_CFG2, &val, 1);
 }
 
 void max77620_low_battery_monitor_config()
 {
     uint8_t val = (MAX77620_CNFGGLBL1_LBDAC_EN | MAX77620_CNFGGLBL1_LBHYST_N | MAX77620_CNFGGLBL1_LBDAC_N);
-    i2c_send(4, 0x3C, MAX77620_REG_CNFGGLBL1, &val, 1);
+    i2c_send(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_CNFGGLBL1, &val, 1);
 }
diff --git a/fusee/fusee-secondary/src/nxboot.c b/fusee/fusee-secondary/src/nxboot.c
index 17a9b5f0c..dbe0882b1 100644
--- a/fusee/fusee-secondary/src/nxboot.c
+++ b/fusee/fusee-secondary/src/nxboot.c
@@ -7,10 +7,13 @@
 #include "fs_utils.h"
 #include "nxboot.h"
 #include "nxfs.h"
+#include "bct.h"
 #include "di.h"
 #include "mc.h"
 #include "se.h"
 #include "pmc.h"
+#include "i2c.h"
+#include "max77620.h"
 #include "cluster.h"
 #include "flow.h"
 #include "timers.h"
@@ -78,13 +81,98 @@ static void nxboot_configure_exosphere(uint32_t target_firmware) {
     *(MAILBOX_EXOSPHERE_CONFIGURATION) = exo_cfg;
 }
 
+static void nxboot_set_bootreason() {
+    boot_reason_t boot_reason = {0};
+    FILE *boot0; 
+    nvboot_config_table *bct;
+    nv_bootloader_info *bootloader_info;
+
+    /* Allocate memory for the BCT. */
+    bct = malloc(sizeof(nvboot_config_table));
+    if (bct == NULL) {
+        fatal_error("[NXBOOT]: Out of memory!\n");
+    }
+    
+    /* Open boot0. */
+    boot0 = fopen("boot0:/", "rb");
+    if (boot0 == NULL) {
+        fatal_error("[NXBOOT]: Failed to open boot0!\n");
+    }
+
+    /* Read the BCT. */
+    if (fread(bct, sizeof(nvboot_config_table), 1, boot0) == 0) {
+        fatal_error("[NXBOOT]: Failed to read the BCT!\n");
+    }
+    
+    /* Close boot0. */
+    fclose(boot0);
+    
+    /* Populate bootloader parameters. */
+    bootloader_info = &bct->bootloader[0];
+    boot_reason.bootloader_version = bootloader_info->version;
+    boot_reason.bootloader_start_block = bootloader_info->start_blk;
+    boot_reason.bootloader_start_page = bootloader_info->start_page;
+    boot_reason.bootloader_attribute = bootloader_info->attribute;
+    
+    uint8_t power_key_intr = 0;
+    uint8_t rtc_intr = 0;
+    i2c_query(I2C_5, MAX77620_PWR_I2C_ADDR, MAX77620_REG_ONOFFIRQ, &power_key_intr, 1);
+    i2c_query(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_REG_RTCINT, &rtc_intr, 1);
+    
+    /* Set PMIC value. */
+    boot_reason.boot_reason_value = ((rtc_intr << 0x08) | power_key_intr);
+    
+    /* TODO: Find out what these mean. */
+    if (power_key_intr & 0x80)
+        boot_reason.boot_reason_state = 0x01;
+    else if (power_key_intr & 0x08)
+        boot_reason.boot_reason_state = 0x02;
+    else if (rtc_intr & 0x02)
+        boot_reason.boot_reason_state = 0x03;
+    else if (rtc_intr & 0x04)
+        boot_reason.boot_reason_state = 0x04;
+    
+    /* Set in memory. */
+    memcpy((void *)MAILBOX_NX_BOOTLOADER_BOOT_REASON, &boot_reason, sizeof(boot_reason));
+    
+    /* Clean up. */
+    free(bct);
+}
+
+static void nxboot_move_bootconfig() {
+    FILE *bcfile;
+    void *bootconfig;
+    
+    /* Allocate memory for reading BootConfig. */
+    bootconfig = memalign(0x1000, 0x4000);
+    if (bootconfig == NULL) {
+        fatal_error("[NXBOOT]: Out of memory!\n");
+    }
+    
+    /* Get BootConfig from the Package2 partition. */
+    bcfile = fopen("bcpkg21:/", "rb");
+    if (bcfile == NULL) {
+        fatal_error("[NXBOOT]: Failed to open BootConfig from eMMC!\n");
+    }
+    if (fread(bootconfig, 0x4000, 1, bcfile) < 1) {
+        fatal_error("[NXBOOT]: Failed to read BootConfig!\n");
+    }
+    fclose(bcfile);
+    
+    /* Copy the first 0x3000 bytes into IRAM. */
+    memset((void *)0x4003D000, 0, 0x3000);
+    memcpy((void *)0x4003D000, bootconfig, 0x3000);
+    
+    /* Clean up. */
+    free(bootconfig);
+}
+
 /* This is the main function responsible for booting Horizon. */
 static nx_keyblob_t __attribute__((aligned(16))) g_keyblobs[32];
 void nxboot_main(void) {
     volatile tegra_pmc_t *pmc = pmc_get_regs();
     volatile tegra_se_t *se = se_get_regs();
     loader_ctx_t *loader_ctx = get_loader_ctx();
-    /* void *bootconfig; */
     package2_header_t *package2;
     size_t package2_size;
     void *tsec_fw;
@@ -101,7 +189,7 @@ void nxboot_main(void) {
     void *exosphere_memaddr;
 
     /* Allocate memory for reading Package2. */
-    package2 = memalign(4096, PACKAGE2_SIZE_MAX);
+    package2 = memalign(0x1000, PACKAGE2_SIZE_MAX);
     if (package2 == NULL) {
         fatal_error("[NXBOOT]: Out of memory!\n");
     }
@@ -115,10 +203,12 @@ void nxboot_main(void) {
         }
     } else {
         pk2file = fopen("bcpkg21:/", "rb");
-        if (pk2file == NULL || fseek(pk2file, 0x4000, SEEK_SET) != 0) {
-            printf("[NXBOOT]: Failed to open Package2 from eMMC: %s!\n", strerror(errno));
+        if (pk2file == NULL) {
+            fatal_error("[NXBOOT]: Failed to open Package2 from eMMC: %s!\n", strerror(errno));
+        }
+        if (fseek(pk2file, 0x4000, SEEK_SET) != 0) {
+            fatal_error("[NXBOOT]: Failed to seek Package2 in eMMC: %s!\n", strerror(errno));
             fclose(pk2file);
-            generic_panic();
         }
     }
 
@@ -127,7 +217,7 @@ void nxboot_main(void) {
         fatal_error("[NXBOOT]: Failed to read Package2!\n");
     }
     package2_size = package2_meta_get_size(&package2->metadata);
-    if (package2_size > PACKAGE2_SIZE_MAX || package2_size <= sizeof(package2_header_t)) {
+    if ((package2_size > PACKAGE2_SIZE_MAX) || (package2_size <= sizeof(package2_header_t))) {
         fatal_error("[NXBOOT]: Package2 is too big or too small!\n");
     }
     if (fread(package2->data, package2_size - sizeof(package2_header_t), 1, pk2file) < 1) {
@@ -138,7 +228,7 @@ void nxboot_main(void) {
     /* Read and parse boot0. */
     printf("[NXBOOT]: Reading boot0...\n");
     boot0 = fopen("boot0:/", "rb");
-    if (boot0 == NULL || package1_read_and_parse_boot0(&package1loader, &package1loader_size, g_keyblobs, &available_revision, boot0) == -1) {
+    if ((boot0 == NULL) || (package1_read_and_parse_boot0(&package1loader, &package1loader_size, g_keyblobs, &available_revision, boot0) == -1)) {
         fatal_error("[NXBOOT]: Couldn't parse boot0: %s!\n", strerror(errno));
     }
     fclose(boot0);
@@ -146,13 +236,15 @@ void nxboot_main(void) {
     /* Read the TSEC firmware from a file, otherwise from PK1L. */
     if (loader_ctx->tsecfw_path[0] != '\0') {
         tsec_fw_size = get_file_size(loader_ctx->tsecfw_path);
-        if (tsec_fw_size != 0 && tsec_fw_size != 0xF00) {
+        if ((tsec_fw_size != 0) && (tsec_fw_size != 0xF00)) {
             fatal_error("[NXBOOT]: TSEC firmware from %s has a wrong size!\n", loader_ctx->tsecfw_path);
         } else if (tsec_fw_size == 0) {
             fatal_error("[NXBOOT]: Could not read the TSEC firmware from %s!\n", loader_ctx->tsecfw_path);
         }
-
+        
+        /* Allocate memory for the TSEC firmware. */
         tsec_fw = memalign(0x100, tsec_fw_size);
+        
         if (tsec_fw == NULL) {
             fatal_error("[NXBOOT]: Out of memory!\n");
         }
@@ -165,10 +257,6 @@ void nxboot_main(void) {
             fatal_error("[NXBOOT]: Failed to read the TSEC firmware from Package1loader!\n");
         }
     }
-
-    /* TODO: Validate that we're capable of booting. */
-
-    /* TODO: Initialize Boot Reason. */
     
     /* Find the system's target firmware. */
     uint32_t target_firmware = nxboot_get_target_firmware(package1loader);
@@ -180,6 +268,12 @@ void nxboot_main(void) {
     /* Setup boot configuration for Exosphère. */
     nxboot_configure_exosphere(target_firmware);
     
+    /* Initialize Boot Reason on older firmware versions. */
+    if (MAILBOX_EXOSPHERE_CONFIGURATION->target_firmware < EXOSPHERE_TARGET_FIRMWARE_400) {
+        printf("[NXBOOT]: Initializing Boot Reason...\n");
+        nxboot_set_bootreason();
+    }
+    
     /* Derive keydata. */
     if (derive_nx_keydata(MAILBOX_EXOSPHERE_CONFIGURATION->target_firmware, g_keyblobs, available_revision, tsec_fw, tsec_fw_size) != 0) {
         fatal_error("[NXBOOT]: Key derivation failed!\n");
@@ -192,7 +286,9 @@ void nxboot_main(void) {
             fatal_error("[NXBOOT]: Could not read the warmboot firmware from %s!\n", loader_ctx->warmboot_path);
         }
 
+        /* Allocate memory for the warmboot firmware. */
         warmboot_fw = malloc(warmboot_fw_size);
+        
         if (warmboot_fw == NULL) {
             fatal_error("[NXBOOT]: Out of memory!\n");
         }
@@ -236,32 +332,36 @@ void nxboot_main(void) {
     /* Patch package2, adding Thermosphère + custom KIPs. */
     package2_rebuild_and_copy(package2, MAILBOX_EXOSPHERE_CONFIGURATION->target_firmware);
 
-    printf(u8"Reading Exosphère...\n");
+    printf(u8"[NXBOOT]: Reading Exosphère...\n");
     
     /* Select the right address for Exosphère. */
     if (MAILBOX_EXOSPHERE_CONFIGURATION->target_firmware <= EXOSPHERE_TARGET_FIRMWARE_400) {
-        exosphere_memaddr = (void *)0x40020000;
+        exosphere_memaddr = (void *)0x4002D000;
     } else {
-        exosphere_memaddr = (void *)0x40018000; /* 5.x has its secmon's crt0 around this region. */
+        exosphere_memaddr = (void *)0x4002B000;
     }
 
     /* Copy Exosphère to a good location or read it directly to it. */
     if (loader_ctx->exosphere_path[0] != '\0') {
         size_t exosphere_size = get_file_size(loader_ctx->exosphere_path);
         if (exosphere_size == 0) {
-            fatal_error(u8"Could not read Exosphère from %s!\n", loader_ctx->exosphere_path);
+            fatal_error(u8"[NXBOOT]: Could not read Exosphère from %s!\n", loader_ctx->exosphere_path);
         } else if (exosphere_size > 0x10000) {
             /* The maximum is actually a bit less than that. */
-            fatal_error(u8"Exosphère from %s is too big!\n", loader_ctx->exosphere_path);
+            fatal_error(u8"[NXBOOT]: Exosphère from %s is too big!\n", loader_ctx->exosphere_path);
         }
 
         if (read_from_file(exosphere_memaddr, exosphere_size, loader_ctx->exosphere_path) != exosphere_size) {
-            fatal_error(u8"Could not read Exosphère from %s!\n", loader_ctx->exosphere_path);
+            fatal_error(u8"[NXBOOT]: Could not read Exosphère from %s!\n", loader_ctx->exosphere_path);
         }
     } else {
         memcpy(exosphere_memaddr, exosphere_bin, exosphere_bin_size);
     }
     
+    /* Move BootConfig. */
+    printf("[NXBOOT]: Moving BootConfig...\n");
+    nxboot_move_bootconfig();
+    
     /* Clean up. */
     free(package1loader);
     if (loader_ctx->tsecfw_path[0] != '\0') {
@@ -287,9 +387,6 @@ void nxboot_main(void) {
         set_aes_keyslot_flags(KEYSLOT_SWITCH_4XOLDDEVICEKEY, 0xFF);
     }
 
-    /* TODO: Handle bootconfig. */
-    memset((void *)0x4003D000, 0, 0x3000);
-    
     /* Finalize the GPU UCODE carveout. */
     mc_config_carveout_finalize();
     
diff --git a/fusee/fusee-secondary/src/nxboot.h b/fusee/fusee-secondary/src/nxboot.h
index 32710d7eb..5f24266d3 100644
--- a/fusee/fusee-secondary/src/nxboot.h
+++ b/fusee/fusee-secondary/src/nxboot.h
@@ -5,22 +5,26 @@
 
 #define MAILBOX_NX_BOOTLOADER_BASE ((void *)(0x40002000))
 
+#define MAILBOX_NX_BOOTLOADER_BOOT_REASON (MAILBOX_NX_BOOTLOADER_BASE + 0xE10)
 #define MAILBOX_NX_BOOTLOADER_SETUP_STATE MAKE_REG32(MAILBOX_NX_BOOTLOADER_BASE + 0xEF8)
+#define MAILBOX_NX_BOOTLOADER_IS_SECMON_AWAKE MAKE_REG32(MAILBOX_NX_BOOTLOADER_BASE + 0xEFC)
 
 #define NX_BOOTLOADER_STATE_INIT 0
 #define NX_BOOTLOADER_STATE_MOVED_BOOTCONFIG 1
-
 #define NX_BOOTLOADER_STATE_LOADED_PACKAGE2 2
 #define NX_BOOTLOADER_STATE_FINISHED 3
-
 #define NX_BOOTLOADER_STATE_DRAM_INITIALIZED_4X 2
 #define NX_BOOTLOADER_STATE_LOADED_PACKAGE2_4X 3
 #define NX_BOOTLOADER_STATE_FINISHED_4X 4
 
-/* Physaddr 0x40002EFC */
-#define MAILBOX_NX_BOOTLOADER_IS_SECMON_AWAKE MAKE_REG32(MAILBOX_NX_BOOTLOADER_BASE + 0xEFC)
-
-#define MAILBOX_NX_BOOTLOADER_BOOT_REASON (MAILBOX_NX_BOOTLOADER_BASE + 0xE10)
+typedef struct {
+    uint32_t bootloader_version;
+    uint32_t bootloader_start_block;
+    uint32_t bootloader_start_page;
+    uint32_t bootloader_attribute;
+    uint32_t boot_reason_value;
+    uint32_t boot_reason_state;
+} boot_reason_t;
 
 void nxboot_main(void);