diff --git a/SConscript b/SConscript
index 8f4db5993..f6501e88c 100644
--- a/SConscript
+++ b/SConscript
@@ -167,7 +167,9 @@ Export('base_project_f4', 'base_project_h7', 'build_project')
 
 # Common autogenerated includes
 with open("board/obj/gitversion.h", "w") as f:
-  f.write(f'const uint8_t gitversion[] = "{get_version(BUILDER, BUILD_TYPE)}";\n')
+  version = get_version(BUILDER, BUILD_TYPE)
+  f.write(f'extern const uint8_t gitversion[{len(version)}];\n')
+  f.write(f'const uint8_t gitversion[{len(version)}] = "{version}";\n')
 
 with open("board/obj/version", "w") as f:
   f.write(f'{get_version(BUILDER, BUILD_TYPE)}')
diff --git a/board/can.h b/board/can.h
new file mode 100644
index 000000000..6b1294197
--- /dev/null
+++ b/board/can.h
@@ -0,0 +1,7 @@
+#pragma once
+#include "can_declarations.h"
+
+const uint8_t PANDA_CAN_CNT = 3U;
+const uint8_t PANDA_BUS_CNT = 3U;
+
+const unsigned char dlc_to_len[DLC_TO_LEN_ARRAY_SIZE] = {0U, 1U, 2U, 3U, 4U, 5U, 6U, 7U, 8U, 12U, 16U, 20U, 24U, 32U, 48U, 64U};
diff --git a/board/can_comms.h b/board/can_comms.h
index cd18fdf3e..99ee968b0 100644
--- a/board/can_comms.h
+++ b/board/can_comms.h
@@ -18,7 +18,7 @@ typedef struct {
   uint8_t data[72];
 } asm_buffer;
 
-asm_buffer can_read_buffer = {.ptr = 0U, .tail_size = 0U};
+static asm_buffer can_read_buffer = {.ptr = 0U, .tail_size = 0U};
 
 int comms_can_read(uint8_t *data, uint32_t max_len) {
   uint32_t pos = 0U;
@@ -53,7 +53,7 @@ int comms_can_read(uint8_t *data, uint32_t max_len) {
   return pos;
 }
 
-asm_buffer can_write_buffer = {.ptr = 0U, .tail_size = 0U};
+static asm_buffer can_write_buffer = {.ptr = 0U, .tail_size = 0U};
 
 // send on CAN
 void comms_can_write(const uint8_t *data, uint32_t len) {
diff --git a/board/can_definitions.h b/board/can_declarations.h
similarity index 81%
rename from board/can_definitions.h
rename to board/can_declarations.h
index f3ce43782..8de9bd517 100644
--- a/board/can_definitions.h
+++ b/board/can_declarations.h
@@ -1,7 +1,7 @@
 #pragma once
 
-const uint8_t PANDA_CAN_CNT = 3U;
-const uint8_t PANDA_BUS_CNT = 3U;
+extern const uint8_t PANDA_CAN_CNT;
+extern const uint8_t PANDA_BUS_CNT;
 
 // bump this when changing the CAN packet
 #define CAN_PACKET_VERSION 4
@@ -27,7 +27,8 @@ typedef struct {
   unsigned char data[CANPACKET_DATA_SIZE_MAX];
 } __attribute__((packed, aligned(4))) CANPacket_t;
 
-const unsigned char dlc_to_len[] = {0U, 1U, 2U, 3U, 4U, 5U, 6U, 7U, 8U, 12U, 16U, 20U, 24U, 32U, 48U, 64U};
+#define DLC_TO_LEN_ARRAY_SIZE 16
+extern const unsigned char dlc_to_len[DLC_TO_LEN_ARRAY_SIZE];
 
 #define GET_BUS(msg) ((msg)->bus)
 #define GET_LEN(msg) (dlc_to_len[(msg)->data_len_code])
diff --git a/board/critical.h b/board/critical.h
index c8cf52c7a..ae2d5c0a6 100644
--- a/board/critical.h
+++ b/board/critical.h
@@ -1,5 +1,9 @@
+#include "critical_declarations.h"
+
 // ********************* Critical section helpers *********************
-volatile bool interrupts_enabled = false;
+uint8_t global_critical_depth = 0U;
+
+static volatile bool interrupts_enabled = false;
 
 void enable_interrupts(void) {
   interrupts_enabled = true;
@@ -10,14 +14,3 @@ void disable_interrupts(void) {
   interrupts_enabled = false;
   __disable_irq();
 }
-
-uint8_t global_critical_depth = 0U;
-#define ENTER_CRITICAL()                                      \
-  __disable_irq();                                            \
-  global_critical_depth += 1U;
-
-#define EXIT_CRITICAL()                                       \
-  global_critical_depth -= 1U;                                \
-  if ((global_critical_depth == 0U) && interrupts_enabled) {  \
-    __enable_irq();                                           \
-  }
diff --git a/board/critical_declarations.h b/board/critical_declarations.h
new file mode 100644
index 000000000..42211d46c
--- /dev/null
+++ b/board/critical_declarations.h
@@ -0,0 +1,17 @@
+#pragma once
+
+// ********************* Critical section helpers *********************
+void enable_interrupts(void);
+void disable_interrupts(void);
+
+extern uint8_t global_critical_depth;
+
+#define ENTER_CRITICAL()                                      \
+  __disable_irq();                                            \
+  global_critical_depth += 1U;
+
+#define EXIT_CRITICAL()                                       \
+  global_critical_depth -= 1U;                                \
+  if ((global_critical_depth == 0U) && interrupts_enabled) {  \
+    __enable_irq();                                           \
+  }
diff --git a/board/faults.h b/board/faults.h
index dc6c1f2aa..0fc9d2c5c 100644
--- a/board/faults.h
+++ b/board/faults.h
@@ -1,38 +1,4 @@
-#define FAULT_STATUS_NONE 0U
-#define FAULT_STATUS_TEMPORARY 1U
-#define FAULT_STATUS_PERMANENT 2U
-
-// Fault types, matches cereal.log.PandaState.FaultType
-#define FAULT_RELAY_MALFUNCTION             (1UL << 0)
-#define FAULT_UNUSED_INTERRUPT_HANDLED      (1UL << 1)
-#define FAULT_INTERRUPT_RATE_CAN_1          (1UL << 2)
-#define FAULT_INTERRUPT_RATE_CAN_2          (1UL << 3)
-#define FAULT_INTERRUPT_RATE_CAN_3          (1UL << 4)
-#define FAULT_INTERRUPT_RATE_TACH           (1UL << 5)
-#define FAULT_INTERRUPT_RATE_GMLAN          (1UL << 6)   // deprecated
-#define FAULT_INTERRUPT_RATE_INTERRUPTS     (1UL << 7)
-#define FAULT_INTERRUPT_RATE_SPI_DMA        (1UL << 8)
-#define FAULT_INTERRUPT_RATE_SPI_CS         (1UL << 9)
-#define FAULT_INTERRUPT_RATE_UART_1         (1UL << 10)
-#define FAULT_INTERRUPT_RATE_UART_2         (1UL << 11)
-#define FAULT_INTERRUPT_RATE_UART_3         (1UL << 12)
-#define FAULT_INTERRUPT_RATE_UART_5         (1UL << 13)
-#define FAULT_INTERRUPT_RATE_UART_DMA       (1UL << 14)
-#define FAULT_INTERRUPT_RATE_USB            (1UL << 15)
-#define FAULT_INTERRUPT_RATE_TIM1           (1UL << 16)
-#define FAULT_INTERRUPT_RATE_TIM3           (1UL << 17)
-#define FAULT_REGISTER_DIVERGENT            (1UL << 18)
-#define FAULT_INTERRUPT_RATE_KLINE_INIT     (1UL << 19)
-#define FAULT_INTERRUPT_RATE_CLOCK_SOURCE   (1UL << 20)
-#define FAULT_INTERRUPT_RATE_TICK           (1UL << 21)
-#define FAULT_INTERRUPT_RATE_EXTI           (1UL << 22)
-#define FAULT_INTERRUPT_RATE_SPI            (1UL << 23)
-#define FAULT_INTERRUPT_RATE_UART_7         (1UL << 24)
-#define FAULT_SIREN_MALFUNCTION             (1UL << 25)
-#define FAULT_HEARTBEAT_LOOP_WATCHDOG       (1UL << 26)
-
-// Permanent faults
-#define PERMANENT_FAULTS 0U
+#include "faults_declarations.h"
 
 uint8_t fault_status = FAULT_STATUS_NONE;
 uint32_t faults = 0U;
diff --git a/board/faults_declarations.h b/board/faults_declarations.h
new file mode 100644
index 000000000..4ef03087b
--- /dev/null
+++ b/board/faults_declarations.h
@@ -0,0 +1,43 @@
+#pragma once
+
+#define FAULT_STATUS_NONE 0U
+#define FAULT_STATUS_TEMPORARY 1U
+#define FAULT_STATUS_PERMANENT 2U
+
+// Fault types, matches cereal.log.PandaState.FaultType
+#define FAULT_RELAY_MALFUNCTION             (1UL << 0)
+#define FAULT_UNUSED_INTERRUPT_HANDLED      (1UL << 1)
+#define FAULT_INTERRUPT_RATE_CAN_1          (1UL << 2)
+#define FAULT_INTERRUPT_RATE_CAN_2          (1UL << 3)
+#define FAULT_INTERRUPT_RATE_CAN_3          (1UL << 4)
+#define FAULT_INTERRUPT_RATE_TACH           (1UL << 5)
+#define FAULT_INTERRUPT_RATE_GMLAN          (1UL << 6)   // deprecated
+#define FAULT_INTERRUPT_RATE_INTERRUPTS     (1UL << 7)
+#define FAULT_INTERRUPT_RATE_SPI_DMA        (1UL << 8)
+#define FAULT_INTERRUPT_RATE_SPI_CS         (1UL << 9)
+#define FAULT_INTERRUPT_RATE_UART_1         (1UL << 10)
+#define FAULT_INTERRUPT_RATE_UART_2         (1UL << 11)
+#define FAULT_INTERRUPT_RATE_UART_3         (1UL << 12)
+#define FAULT_INTERRUPT_RATE_UART_5         (1UL << 13)
+#define FAULT_INTERRUPT_RATE_UART_DMA       (1UL << 14)
+#define FAULT_INTERRUPT_RATE_USB            (1UL << 15)
+#define FAULT_INTERRUPT_RATE_TIM1           (1UL << 16)
+#define FAULT_INTERRUPT_RATE_TIM3           (1UL << 17)
+#define FAULT_REGISTER_DIVERGENT            (1UL << 18)
+#define FAULT_INTERRUPT_RATE_KLINE_INIT     (1UL << 19)
+#define FAULT_INTERRUPT_RATE_CLOCK_SOURCE   (1UL << 20)
+#define FAULT_INTERRUPT_RATE_TICK           (1UL << 21)
+#define FAULT_INTERRUPT_RATE_EXTI           (1UL << 22)
+#define FAULT_INTERRUPT_RATE_SPI            (1UL << 23)
+#define FAULT_INTERRUPT_RATE_UART_7         (1UL << 24)
+#define FAULT_SIREN_MALFUNCTION             (1UL << 25)
+#define FAULT_HEARTBEAT_LOOP_WATCHDOG       (1UL << 26)
+
+// Permanent faults
+#define PERMANENT_FAULTS 0U
+
+extern uint8_t fault_status;
+extern uint32_t faults;
+
+void fault_occurred(uint32_t fault);
+void fault_recovered(uint32_t fault);
diff --git a/board/main.c b/board/main.c
index 7f95abade..9264e06bb 100644
--- a/board/main.c
+++ b/board/main.c
@@ -31,7 +31,7 @@
 
 // ********************* Serial debugging *********************
 
-bool check_started(void) {
+static bool check_started(void) {
   bool started = current_board->check_ignition() || ignition_can;
   return started;
 }
@@ -127,11 +127,12 @@ bool is_car_safety_mode(uint16_t mode) {
 // ***************************** main code *****************************
 
 // cppcheck-suppress unusedFunction ; used in headers not included in cppcheck
+// cppcheck-suppress misra-c2012-8.4
 void __initialize_hardware_early(void) {
   early_initialization();
 }
 
-void __attribute__ ((noinline)) enable_fpu(void) {
+static void __attribute__ ((noinline)) enable_fpu(void) {
   // enable the FPU
   SCB->CPACR |= ((3UL << (10U * 2U)) | (3UL << (11U * 2U)));
 }
@@ -141,9 +142,12 @@ void __attribute__ ((noinline)) enable_fpu(void) {
 #define HEARTBEAT_IGNITION_CNT_OFF 2U
 
 // called at 8Hz
-uint8_t loop_counter = 0U;
-uint8_t prev_harness_status = HARNESS_STATUS_NC;
-void tick_handler(void) {
+static void tick_handler(void) {
+  static uint32_t siren_countdown = 0; // siren plays while countdown > 0
+  static uint32_t controls_allowed_countdown = 0;
+  static uint8_t prev_harness_status = HARNESS_STATUS_NC;
+  static uint8_t loop_counter = 0U;
+
   if (TICK_TIMER->SR != 0U) {
 
     // siren
diff --git a/board/main_declarations.h b/board/main_declarations.h
index a1496c0d0..2704a01a0 100644
--- a/board/main_declarations.h
+++ b/board/main_declarations.h
@@ -1,3 +1,5 @@
+#pragma once
+
 // ******************** Prototypes ********************
 void print(const char *a);
 void puth(unsigned int i);
@@ -10,18 +12,15 @@ void pwm_init(TIM_TypeDef *TIM, uint8_t channel);
 void pwm_set(TIM_TypeDef *TIM, uint8_t channel, uint8_t percentage);
 
 // ********************* Globals **********************
-uint8_t hw_type = 0;
-board *current_board;
-uint32_t uptime_cnt = 0;
-bool green_led_enabled = false;
+extern uint8_t hw_type;
+extern board *current_board;
+extern uint32_t uptime_cnt;
+extern bool green_led_enabled;
 
 // heartbeat state
-uint32_t heartbeat_counter = 0;
-bool heartbeat_lost = false;
-bool heartbeat_disabled = false;            // set over USB
+extern uint32_t heartbeat_counter;
+extern bool heartbeat_lost;
+extern bool heartbeat_disabled;            // set over USB
 
 // siren state
-bool siren_enabled = false;
-uint32_t siren_countdown = 0; // siren plays while countdown > 0
-uint32_t controls_allowed_countdown = 0;
-
+extern bool siren_enabled;
diff --git a/board/main_definitions.h b/board/main_definitions.h
new file mode 100644
index 000000000..137d98736
--- /dev/null
+++ b/board/main_definitions.h
@@ -0,0 +1,15 @@
+#include "main_declarations.h"
+
+// ********************* Globals **********************
+uint8_t hw_type = 0;
+board *current_board;
+uint32_t uptime_cnt = 0;
+bool green_led_enabled = false;
+
+// heartbeat state
+uint32_t heartbeat_counter = 0;
+bool heartbeat_lost = false;
+bool heartbeat_disabled = false;            // set over USB
+
+// siren state
+bool siren_enabled = false;
diff --git a/board/power_saving.h b/board/power_saving.h
index 61541cae9..7fcc181ea 100644
--- a/board/power_saving.h
+++ b/board/power_saving.h
@@ -1,9 +1,8 @@
+#include "power_saving_declarations.h"
+
 // WARNING: To stay in compliance with the SIL2 rules laid out in STM UM1840, we should never implement any of the available hardware low power modes.
 // See rule: CoU_3
 
-#define POWER_SAVE_STATUS_DISABLED 0
-#define POWER_SAVE_STATUS_ENABLED 1
-
 int power_save_status = POWER_SAVE_STATUS_DISABLED;
 
 void set_power_save_state(int state) {
diff --git a/board/power_saving_declarations.h b/board/power_saving_declarations.h
new file mode 100644
index 000000000..7a474a559
--- /dev/null
+++ b/board/power_saving_declarations.h
@@ -0,0 +1,11 @@
+#pragma once
+
+// WARNING: To stay in compliance with the SIL2 rules laid out in STM UM1840, we should never implement any of the available hardware low power modes.
+// See rule: CoU_3
+
+#define POWER_SAVE_STATUS_DISABLED 0
+#define POWER_SAVE_STATUS_ENABLED 1
+
+extern int power_save_status;
+
+void set_power_save_state(int state);
diff --git a/board/provision.h b/board/provision.h
index 2a8ce893d..d191e53f6 100644
--- a/board/provision.h
+++ b/board/provision.h
@@ -3,9 +3,9 @@
 
 #define PROVISION_CHUNK_LEN 0x20
 
-const unsigned char unprovisioned_text[] = "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff";
-
 void get_provision_chunk(uint8_t *resp) {
+  const unsigned char unprovisioned_text[] = "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff";
+
   (void)memcpy(resp, (uint8_t *)PROVISION_CHUNK_ADDRESS, PROVISION_CHUNK_LEN);
   if (memcmp(resp, unprovisioned_text, 0x20) == 0) {
     (void)memcpy(resp, "unprovisioned\x00\x00\x00testing123\x00\x00\xa3\xa6\x99\xec", 0x20);
diff --git a/board/safety.h b/board/safety.h
index 048d7cca4..1c1616e72 100644
--- a/board/safety.h
+++ b/board/safety.h
@@ -1,5 +1,5 @@
 #include "safety_declarations.h"
-#include "can_definitions.h"
+#include "can.h"
 
 // include the safety policies.
 #include "safety/safety_defaults.h"
diff --git a/board/stm32f4/stm32f4_config.h b/board/stm32f4/stm32f4_config.h
index 85baff25b..faef88f99 100644
--- a/board/stm32f4/stm32f4_config.h
+++ b/board/stm32f4/stm32f4_config.h
@@ -33,11 +33,11 @@
 #define PROVISION_CHUNK_ADDRESS 0x1FFF79E0U
 #define DEVICE_SERIAL_NUMBER_ADDRESS 0x1FFF79C0U
 
-#include "can_definitions.h"
+#include "can.h"
 #include "comms_definitions.h"
 
 #ifndef BOOTSTUB
-  #include "main_declarations.h"
+  #include "main_definitions.h"
 #else
   #include "bootstub_declarations.h"
 #endif
diff --git a/board/stm32h7/stm32h7_config.h b/board/stm32h7/stm32h7_config.h
index 64f149848..fcf14876f 100644
--- a/board/stm32h7/stm32h7_config.h
+++ b/board/stm32h7/stm32h7_config.h
@@ -46,11 +46,11 @@ separate IRQs for RX and TX.
 #define PROVISION_CHUNK_ADDRESS 0x080FFFE0U
 #define DEVICE_SERIAL_NUMBER_ADDRESS 0x080FFFC0U
 
-#include "can_definitions.h"
+#include "can.h"
 #include "comms_definitions.h"
 
 #ifndef BOOTSTUB
-  #include "main_declarations.h"
+  #include "main_definitions.h"
 #else
   #include "bootstub_declarations.h"
 #endif
diff --git a/tests/libpanda/panda.c b/tests/libpanda/panda.c
index f34c02804..66a21f80c 100644
--- a/tests/libpanda/panda.c
+++ b/tests/libpanda/panda.c
@@ -1,6 +1,6 @@
 #include "fake_stm.h"
 #include "config.h"
-#include "can_definitions.h"
+#include "can.h"
 
 bool can_init(uint8_t can_number) { return true; }
 void process_can(uint8_t can_number) { }
@@ -16,7 +16,7 @@ void can_tx_comms_resume_spi(void) { };
 #include "libc.h"
 #include "boards/board_declarations.h"
 #include "safety.h"
-#include "main_declarations.h"
+#include "main_definitions.h"
 #include "drivers/can_common.h"
 
 can_ring *rx_q = &can_rx_q;