diff --git a/src/Kconfig b/src/Kconfig
index cc557fb77..915af2956 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -87,6 +87,46 @@ config USB_SERIAL_NUMBER
     string "USB serial number" if !USB_SERIAL_NUMBER_CHIPID
 endmenu
 
+# Optional features that can be disabled (for devices with small flash sizes)
+config WANT_GPIO_BITBANGING
+    bool
+    depends on HAVE_GPIO
+    default y
+config WANT_DISPLAYS
+    bool
+    depends on HAVE_GPIO
+    default y
+config WANT_SENSORS
+    bool
+    depends on HAVE_GPIO_I2C || HAVE_GPIO_SPI
+    default y
+config WANT_SOFTWARE_I2C
+    bool
+    depends on HAVE_GPIO && HAVE_GPIO_I2C
+    default y
+config WANT_SOFTWARE_SPI
+    bool
+    depends on HAVE_GPIO && HAVE_GPIO_SPI
+    default y
+menu "Optional features (to reduce code size)"
+    depends on HAVE_LIMITED_CODE_SIZE
+config WANT_GPIO_BITBANGING
+    bool "Support GPIO \"bit-banging\" devices"
+    depends on HAVE_GPIO
+config WANT_DISPLAYS
+    bool "Support LCD devices"
+    depends on HAVE_GPIO
+config WANT_SENSORS
+    bool "Support external sensor devices"
+    depends on HAVE_GPIO_I2C || HAVE_GPIO_SPI
+config WANT_SOFTWARE_I2C
+    bool "Support software based I2C \"bit-banging\""
+    depends on HAVE_GPIO && HAVE_GPIO_I2C
+config WANT_SOFTWARE_SPI
+    bool "Support software based SPI \"bit-banging\""
+    depends on HAVE_GPIO && HAVE_GPIO_SPI
+endmenu
+
 # Generic configuration options for CANbus
 config CANSERIAL
     bool
@@ -124,8 +164,6 @@ config HAVE_GPIO_I2C
     bool
 config HAVE_GPIO_HARD_PWM
     bool
-config HAVE_GPIO_BITBANGING
-    bool
 config HAVE_STRICT_TIMING
     bool
 config HAVE_CHIPID
@@ -134,6 +172,8 @@ config HAVE_STEPPER_BOTH_EDGE
     bool
 config HAVE_BOOTLOADER_REQUEST
     bool
+config HAVE_LIMITED_CODE_SIZE
+    bool
 
 config INLINE_STEPPER_HACK
     # Enables gcc to inline stepper_event() into the main timer irq handler
diff --git a/src/Makefile b/src/Makefile
index 7881622b0..e89845549 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -4,11 +4,17 @@ src-y += sched.c command.c basecmd.c debugcmds.c
 src-$(CONFIG_HAVE_GPIO) += initial_pins.c gpiocmds.c stepper.c endstop.c \
     trsync.c
 src-$(CONFIG_HAVE_GPIO_ADC) += adccmds.c
-src-$(CONFIG_HAVE_GPIO_SPI) += spicmds.c thermocouple.c
+src-$(CONFIG_HAVE_GPIO_SPI) += spicmds.c
 src-$(CONFIG_HAVE_GPIO_SDIO) += sdiocmds.c
 src-$(CONFIG_HAVE_GPIO_I2C) += i2ccmds.c
 src-$(CONFIG_HAVE_GPIO_HARD_PWM) += pwmcmds.c
-bb-src-$(CONFIG_HAVE_GPIO_SPI) := spi_software.c sensor_adxl345.c sensor_angle.c
-bb-src-$(CONFIG_HAVE_GPIO_I2C) += i2c_software.c sensor_mpu9250.c
-src-$(CONFIG_HAVE_GPIO_BITBANGING) += $(bb-src-y) lcd_st7920.c lcd_hd44780.c \
-    buttons.c tmcuart.c neopixel.c pulse_counter.c
+
+src-$(CONFIG_WANT_GPIO_BITBANGING) += buttons.c tmcuart.c neopixel.c \
+    pulse_counter.c
+src-$(CONFIG_WANT_DISPLAYS) += lcd_st7920.c lcd_hd44780.c
+src-$(CONFIG_WANT_SOFTWARE_SPI) += spi_software.c
+src-$(CONFIG_WANT_SOFTWARE_I2C) += i2c_software.c
+sensors-src-$(CONFIG_HAVE_GPIO_SPI) := thermocouple.c sensor_adxl345.c \
+    sensor_angle.c
+sensors-src-$(CONFIG_HAVE_GPIO_I2C) += sensor_mpu9250.c
+src-$(CONFIG_WANT_SENSORS) += $(sensors-src-y)
diff --git a/src/ar100/Kconfig b/src/ar100/Kconfig
index fc7743da8..bd3050833 100644
--- a/src/ar100/Kconfig
+++ b/src/ar100/Kconfig
@@ -7,8 +7,8 @@ config AR100_SELECT
     default y
     select HAVE_GPIO
     select HAVE_GPIO_SPI
-    select HAVE_GPIO_BITBANGING
     select HAVE_STEPPER_BOTH_EDGE
+    select HAVE_LIMITED_CODE_SIZE
 
 config BOARD_DIRECTORY
     string
diff --git a/src/ar100/Makefile b/src/ar100/Makefile
index d1203a0e8..29693fe20 100644
--- a/src/ar100/Makefile
+++ b/src/ar100/Makefile
@@ -19,12 +19,6 @@ src-y += ar100/main.c ar100/gpio.c ar100/serial.c
 src-y += ar100/util.c ar100/timer.c
 src-y += generic/crc16_ccitt.c generic/timer_irq.c
 
-# Remove files that are not needed to save space
-src-y := $(filter-out lcd_hd44780.c,$(src-y))
-src-y := $(filter-out lcd_st7920.c,$(src-y))
-src-y := $(filter-out sensor_angle.c,$(src-y))
-src-y := $(filter-out thermocouple.c,$(src-y))
-
 OBJS_klipper.elf += $(OUT)lib/ar100/start.o
 OBJS_klipper.elf += $(OUT)lib/ar100/runtime.o
 
diff --git a/src/atsam/Kconfig b/src/atsam/Kconfig
index aa802072e..7fac95f50 100644
--- a/src/atsam/Kconfig
+++ b/src/atsam/Kconfig
@@ -10,7 +10,6 @@ config ATSAM_SELECT
     select HAVE_GPIO_I2C
     select HAVE_GPIO_SPI
     select HAVE_GPIO_HARD_PWM if !MACH_SAME70
-    select HAVE_GPIO_BITBANGING
     select HAVE_STRICT_TIMING
     select HAVE_CHIPID
     select HAVE_STEPPER_BOTH_EDGE
diff --git a/src/atsamd/Kconfig b/src/atsamd/Kconfig
index e1062e534..19709ef39 100644
--- a/src/atsamd/Kconfig
+++ b/src/atsamd/Kconfig
@@ -10,7 +10,6 @@ config ATSAMD_SELECT
     select HAVE_GPIO_I2C
     select HAVE_GPIO_SPI
     select HAVE_GPIO_HARD_PWM if MACH_SAMX2
-    select HAVE_GPIO_BITBANGING
     select HAVE_STRICT_TIMING
     select HAVE_CHIPID
     select HAVE_STEPPER_BOTH_EDGE
diff --git a/src/avr/Kconfig b/src/avr/Kconfig
index fd24852db..ac3ffa2ab 100644
--- a/src/avr/Kconfig
+++ b/src/avr/Kconfig
@@ -10,8 +10,8 @@ config AVR_SELECT
     select HAVE_GPIO_SPI
     select HAVE_GPIO_I2C
     select HAVE_GPIO_HARD_PWM
-    select HAVE_GPIO_BITBANGING if !MACH_atmega168
     select HAVE_STRICT_TIMING
+    select HAVE_LIMITED_CODE_SIZE if MACH_atmega168
 
 config BOARD_DIRECTORY
     string
diff --git a/src/hc32f460/Kconfig b/src/hc32f460/Kconfig
index e204bebf7..9de4a7fc6 100644
--- a/src/hc32f460/Kconfig
+++ b/src/hc32f460/Kconfig
@@ -7,7 +7,6 @@ config HC32F460_SELECT
     default y
     select HAVE_GPIO
     select HAVE_GPIO_ADC
-    select HAVE_GPIO_BITBANGING
     select HAVE_STRICT_TIMING
     select HAVE_GPIO_HARD_PWM
     select HAVE_STEPPER_BOTH_EDGE
diff --git a/src/i2ccmds.c b/src/i2ccmds.c
index 099fe7753..377a9537d 100644
--- a/src/i2ccmds.c
+++ b/src/i2ccmds.c
@@ -5,6 +5,7 @@
 // This file may be distributed under the terms of the GNU GPLv3 license.
 
 #include <string.h> // memcpy
+#include "autoconf.h" // CONFIG_WANT_SOFTWARE_I2C
 #include "basecmd.h" //oid_alloc
 #include "command.h"  //sendf
 #include "sched.h" //DECL_COMMAND
@@ -56,7 +57,7 @@ command_i2c_write(uint32_t *args)
     uint8_t data_len = args[1];
     uint8_t *data = command_decode_ptr(args[2]);
     uint_fast8_t flags = i2c->flags;
-    if (flags & IF_SOFTWARE)
+    if (CONFIG_WANT_SOFTWARE_I2C && flags & IF_SOFTWARE)
         i2c_software_write(i2c->i2c_software, data_len, data);
     else
         i2c_write(i2c->i2c_config, data_len, data);
@@ -73,12 +74,10 @@ command_i2c_read(uint32_t * args)
     uint8_t data_len = args[3];
     uint8_t data[data_len];
     uint_fast8_t flags = i2c->flags;
-    if (flags & IF_SOFTWARE)
-        i2c_software_read(
-            i2c->i2c_software, reg_len, reg, data_len, data);
+    if (CONFIG_WANT_SOFTWARE_I2C && flags & IF_SOFTWARE)
+        i2c_software_read(i2c->i2c_software, reg_len, reg, data_len, data);
     else
-        i2c_read(
-            i2c->i2c_config, reg_len, reg, data_len, data);
+        i2c_read(i2c->i2c_config, reg_len, reg, data_len, data);
     sendf("i2c_read_response oid=%c response=%*s", oid, data_len, data);
 }
 DECL_COMMAND(command_i2c_read, "i2c_read oid=%c reg=%*s read_len=%u");
@@ -98,7 +97,7 @@ command_i2c_modify_bits(uint32_t *args)
     uint8_t receive_data[reg_len + data_len];
     uint_fast8_t flags = i2c->flags;
     memcpy(receive_data, reg, reg_len);
-    if (flags & IF_SOFTWARE)
+    if (CONFIG_WANT_SOFTWARE_I2C && flags & IF_SOFTWARE)
         i2c_software_read(
             i2c->i2c_software, reg_len, reg, data_len, receive_data + reg_len);
     else
@@ -108,7 +107,7 @@ command_i2c_modify_bits(uint32_t *args)
         receive_data[reg_len + i] &= ~clear_set[i];
         receive_data[reg_len + i] |= clear_set[data_len + i];
     }
-    if (flags & IF_SOFTWARE)
+    if (CONFIG_WANT_SOFTWARE_I2C && flags & IF_SOFTWARE)
         i2c_software_write(i2c->i2c_software, reg_len + data_len, receive_data);
     else
         i2c_write(i2c->i2c_config, reg_len + data_len, receive_data);
diff --git a/src/linux/Kconfig b/src/linux/Kconfig
index edf575b08..661f3c302 100644
--- a/src/linux/Kconfig
+++ b/src/linux/Kconfig
@@ -6,12 +6,11 @@ if MACH_LINUX
 config LINUX_SELECT
     bool
     default y
+    select HAVE_GPIO
     select HAVE_GPIO_ADC
     select HAVE_GPIO_SPI
-    select HAVE_GPIO_HARD_PWM
     select HAVE_GPIO_I2C
-    select HAVE_GPIO_BITBANGING
-    select HAVE_GPIO
+    select HAVE_GPIO_HARD_PWM
 
 config BOARD_DIRECTORY
     string
diff --git a/src/lpc176x/Kconfig b/src/lpc176x/Kconfig
index 79c3b3006..390a081f0 100644
--- a/src/lpc176x/Kconfig
+++ b/src/lpc176x/Kconfig
@@ -9,10 +9,9 @@ config LPC_SELECT
     select HAVE_GPIO_ADC
     select HAVE_GPIO_I2C
     select HAVE_GPIO_SPI
-    select HAVE_GPIO_BITBANGING
+    select HAVE_GPIO_HARD_PWM
     select HAVE_STRICT_TIMING
     select HAVE_CHIPID
-    select HAVE_GPIO_HARD_PWM
     select HAVE_STEPPER_BOTH_EDGE
     select HAVE_BOOTLOADER_REQUEST
 
diff --git a/src/pru/Kconfig b/src/pru/Kconfig
index 8956e6bcf..f2c2019a5 100644
--- a/src/pru/Kconfig
+++ b/src/pru/Kconfig
@@ -8,6 +8,7 @@ config PRU_SELECT
     select HAVE_GPIO
     #select HAVE_GPIO_ADC
     select HAVE_STRICT_TIMING
+    select HAVE_LIMITED_CODE_SIZE
 
 config BOARD_DIRECTORY
     string
diff --git a/src/rp2040/Kconfig b/src/rp2040/Kconfig
index ba6f00f80..59891649e 100644
--- a/src/rp2040/Kconfig
+++ b/src/rp2040/Kconfig
@@ -9,7 +9,6 @@ config RP2040_SELECT
     select HAVE_GPIO_ADC
     select HAVE_GPIO_SPI
     select HAVE_GPIO_I2C
-    select HAVE_GPIO_BITBANGING
     select HAVE_STRICT_TIMING
     select HAVE_CHIPID
     select HAVE_GPIO_HARD_PWM
diff --git a/src/spicmds.c b/src/spicmds.c
index 2c3f3ed60..8ea915d9b 100644
--- a/src/spicmds.c
+++ b/src/spicmds.c
@@ -5,7 +5,7 @@
 // This file may be distributed under the terms of the GNU GPLv3 license.
 
 #include <string.h> // memcpy
-#include "autoconf.h" // CONFIG_HAVE_GPIO_BITBANGING
+#include "autoconf.h" // CONFIG_WANT_SOFTWARE_SPI
 #include "board/gpio.h" // gpio_out_write
 #include "basecmd.h" // oid_alloc
 #include "command.h" // DECL_COMMAND
@@ -92,7 +92,7 @@ spidev_transfer(struct spidev_s *spi, uint8_t receive_data
         // Not yet initialized
         return;
 
-    if (CONFIG_HAVE_GPIO_BITBANGING && flags & SF_SOFTWARE)
+    if (CONFIG_WANT_SOFTWARE_SPI && flags & SF_SOFTWARE)
         spi_software_prepare(spi->spi_software);
     else
         spi_prepare(spi->spi_config);
@@ -100,7 +100,7 @@ spidev_transfer(struct spidev_s *spi, uint8_t receive_data
     if (flags & SF_HAVE_PIN)
         gpio_out_write(spi->pin, !!(flags & SF_CS_ACTIVE_HIGH));
 
-    if (CONFIG_HAVE_GPIO_BITBANGING && flags & SF_SOFTWARE)
+    if (CONFIG_WANT_SOFTWARE_SPI && flags & SF_SOFTWARE)
         spi_software_transfer(spi->spi_software, receive_data, data_len, data);
     else
         spi_transfer(spi->spi_config, receive_data, data_len, data);
diff --git a/src/stm32/Kconfig b/src/stm32/Kconfig
index 21e78f533..e39611764 100644
--- a/src/stm32/Kconfig
+++ b/src/stm32/Kconfig
@@ -11,11 +11,11 @@ config STM32_SELECT
     select HAVE_GPIO_SPI if !MACH_STM32F031
     select HAVE_GPIO_SDIO if MACH_STM32F4
     select HAVE_GPIO_HARD_PWM if MACH_STM32F1 || MACH_STM32F4 || MACH_STM32F7 || MACH_STM32G0 || MACH_STM32H7
-    select HAVE_GPIO_BITBANGING if !MACH_STM32F031
     select HAVE_STRICT_TIMING
     select HAVE_CHIPID
     select HAVE_STEPPER_BOTH_EDGE
     select HAVE_BOOTLOADER_REQUEST
+    select HAVE_LIMITED_CODE_SIZE if MACH_STM32F031 || MACH_STM32F042
 
 config BOARD_DIRECTORY
     string
diff --git a/test/configs/ar100.config b/test/configs/ar100.config
index 5abf7bf6e..a717fe3d0 100644
--- a/test/configs/ar100.config
+++ b/test/configs/ar100.config
@@ -1,2 +1,5 @@
 # Base config file for the ar100 CPU
 CONFIG_MACH_AR100=y
+CONFIG_WANT_DISPLAYS=n
+CONFIG_WANT_SOFTWARE_I2C=n
+CONFIG_WANT_SOFTWARE_SPI=n
diff --git a/test/configs/pru.config b/test/configs/pru.config
index eee1a4674..265fbb53c 100644
--- a/test/configs/pru.config
+++ b/test/configs/pru.config
@@ -1,2 +1,4 @@
 # Base config file for the Beaglebone PRU
 CONFIG_MACH_PRU=y
+CONFIG_WANT_GPIO_BITBANGING=n
+CONFIG_WANT_DISPLAYS=n
diff --git a/test/configs/stm32f031.config b/test/configs/stm32f031.config
index 719c6563e..aa9c282be 100644
--- a/test/configs/stm32f031.config
+++ b/test/configs/stm32f031.config
@@ -1,3 +1,5 @@
 # Base config file for STM32F031 boards
 CONFIG_MACH_STM32=y
 CONFIG_MACH_STM32F031=y
+CONFIG_WANT_GPIO_BITBANGING=n
+CONFIG_WANT_DISPLAYS=n