diff --git a/boards/sam4s-xpro/doc.txt b/boards/sam4s-xpro/doc.md
similarity index 99%
rename from boards/sam4s-xpro/doc.txt
rename to boards/sam4s-xpro/doc.md
index 46dae32405..0440206739 100644
--- a/boards/sam4s-xpro/doc.txt
+++ b/boards/sam4s-xpro/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_sam4s-xpro ATSAM4S Xplained Pro board
 @ingroup     boards
 @brief       Support for the ATSAM4S Xplained Pro board
@@ -44,5 +43,3 @@ featuring a SAM4SD32 (Cortex-M4) SoC running up to 120 MHz. This MCU comes with
 By default, openOCD is used for both flashing and debugging.
 EDBG programmer is also available with:
 `PROGRAMMER=edbg BOARD=sam4s-xpro make -C tests/leds flash`
-
- */
diff --git a/boards/samd10-xmini/doc.txt b/boards/samd10-xmini/doc.md
similarity index 99%
rename from boards/samd10-xmini/doc.txt
rename to boards/samd10-xmini/doc.md
index 1d68cbf696..6a087d525e 100644
--- a/boards/samd10-xmini/doc.txt
+++ b/boards/samd10-xmini/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_samd10-xmini Atmel SAM D10 Xplained Mini
 @ingroup     boards
 @brief       Support for the Atmel SAM D10 Xplained Mini board.
@@ -72,5 +71,3 @@ sudo service udev restart
 The I2C pins on the board do not have any pull-ups connected to them.
 That means that running e.g. `i2c_scan` without any I2C slaves connected
 will run into timeouts.
-
- */
diff --git a/boards/samd20-xpro/doc.txt b/boards/samd20-xpro/doc.md
similarity index 99%
rename from boards/samd20-xpro/doc.txt
rename to boards/samd20-xpro/doc.md
index c41ce167b5..037546cb17 100644
--- a/boards/samd20-xpro/doc.txt
+++ b/boards/samd20-xpro/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_samd20-xpro Atmel SAM D20 Xplained Pro
 @ingroup     boards
 @brief       Support for the Atmel SAM D20 Xplained Pro board.
@@ -78,5 +77,3 @@ helpful to understanding how to set up a solid RIOT development environment for
 the SAMD20: http://watr.li/samr21-dev-setup-ubuntu.html
 
 ## Known Issues / Problems
-
- */
diff --git a/boards/samd21-xpro/doc.txt b/boards/samd21-xpro/doc.md
similarity index 99%
rename from boards/samd21-xpro/doc.txt
rename to boards/samd21-xpro/doc.md
index 58c543ecb7..bb26a4a205 100644
--- a/boards/samd21-xpro/doc.txt
+++ b/boards/samd21-xpro/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_samd21-xpro Atmel SAM D21 Xplained Pro
 @ingroup     boards
 @brief       Support for the Atmel SAM D21 Xplained Pro board.
@@ -98,5 +97,3 @@ helpful to understanding how to set up a solid RIOT development environment for
 the SAMD21: http://watr.li/samr21-dev-setup-ubuntu.html
 
 ## Known Issues / Problems
-
- */
diff --git a/boards/same51-curiosity-nano/doc.txt b/boards/same51-curiosity-nano/doc.md
similarity index 99%
rename from boards/same51-curiosity-nano/doc.txt
rename to boards/same51-curiosity-nano/doc.md
index 4212971639..bf1945c3df 100644
--- a/boards/same51-curiosity-nano/doc.txt
+++ b/boards/same51-curiosity-nano/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_same51-curiosity-nano Microchip SAM E51 Curiosity Nano
 @ingroup     boards
 @brief       Support for the Microchip SAM E51 Curiosity Nano board.
@@ -82,5 +81,3 @@ sudo service udev restart
 ```
 
 ## Known Issues / Problems
-
- */
diff --git a/boards/same54-xpro/doc.txt b/boards/same54-xpro/doc.md
similarity index 99%
rename from boards/same54-xpro/doc.txt
rename to boards/same54-xpro/doc.md
index c3e0628133..bdd8cd76bf 100644
--- a/boards/same54-xpro/doc.txt
+++ b/boards/same54-xpro/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_same54-xpro Microchip SAM E54 Xplained Pro
 @ingroup     boards
 @brief       Support for the Microchip SAM E54 Xplained Pro board.
@@ -91,5 +90,3 @@ sudo service udev restart
 ```
 
 ## Known Issues / Problems
-
- */
diff --git a/boards/saml10-xpro/doc.txt b/boards/saml10-xpro/doc.md
similarity index 99%
rename from boards/saml10-xpro/doc.txt
rename to boards/saml10-xpro/doc.md
index c815470169..c65a8d171e 100644
--- a/boards/saml10-xpro/doc.txt
+++ b/boards/saml10-xpro/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_saml10-xpro Microchip SAML10 Xplained Pro
 @ingroup     boards
 @brief       Support for the Microchip SAML10 Xplained Pro board.
@@ -65,5 +64,3 @@ memory.
 Connect the device to your Micro-USB cable.
 
 The standard method for flashing RIOT to the saml10-xpro is using EDBG.
-
- */
diff --git a/boards/saml11-xpro/doc.txt b/boards/saml11-xpro/doc.md
similarity index 99%
rename from boards/saml11-xpro/doc.txt
rename to boards/saml11-xpro/doc.md
index 07fc18805a..f0222aa4cb 100644
--- a/boards/saml11-xpro/doc.txt
+++ b/boards/saml11-xpro/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_saml11-xpro Microchip SAML11 Xplained Pro
 @ingroup     boards
 @brief       Support for the Microchip SAML11 Xplained Pro board.
@@ -78,5 +77,3 @@ flash memory. Such action can be done with the following EDBG command:
 'edbg -t saml11 -F w0,194,1'
 or pass it as argument when calling make:
 EDBG_ARGS="-F w0,194,1" BOARD=saml11-xpro make flash term -C tests/periph/uart
-
-*/
diff --git a/boards/saml21-xpro/doc.txt b/boards/saml21-xpro/doc.md
similarity index 99%
rename from boards/saml21-xpro/doc.txt
rename to boards/saml21-xpro/doc.md
index 6477bdb4ed..a4245d56d0 100644
--- a/boards/saml21-xpro/doc.txt
+++ b/boards/saml21-xpro/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_saml21-xpro Atmel SAM L21 Xplained Pro
 @ingroup     boards
 @brief       Support for the Atmel SAM L21 Xplained Pro board.
@@ -106,5 +105,3 @@ helpful to understanding how to set up a solid RIOT development environment for
 the SAML21: http://watr.li/samr21-dev-setup-ubuntu.html
 
 ## Known Issues / Problems
-
- */
diff --git a/boards/samr21-xpro/doc.txt b/boards/samr21-xpro/doc.md
similarity index 99%
rename from boards/samr21-xpro/doc.txt
rename to boards/samr21-xpro/doc.md
index 4ccf4e965e..e3b6cf2817 100644
--- a/boards/samr21-xpro/doc.txt
+++ b/boards/samr21-xpro/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_samr21-xpro Atmel SAM R21 Xplained Pro
 @ingroup     boards
 @brief       Support for the Atmel SAM R21 Xplained Pro board.
@@ -203,4 +202,3 @@ But when you try to flash again, you could get a CMSIS-DAP related error. It
 seems to only happen with USB 3.0 ports. You can take a look at
 [Vagrant](http://en.wikipedia.org/wiki/Vagrant_%28software%29) and use a virtual
 Linux to run the virtual RIOT, and flash from macOS.
- */
diff --git a/boards/samr34-xpro/doc.txt b/boards/samr34-xpro/doc.md
similarity index 99%
rename from boards/samr34-xpro/doc.txt
rename to boards/samr34-xpro/doc.md
index 7c92e0f2c4..661953f9de 100644
--- a/boards/samr34-xpro/doc.txt
+++ b/boards/samr34-xpro/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_samr34-xpro Microchip SAM R34 Xplained Pro
 @ingroup     boards
 @brief       Support for the Microchip SAM R34 Xplained Pro and WLR089 Xplained Pro
@@ -36,5 +35,3 @@ An evaluation board for the radio certified WLR089 module exists as the WLR089 X
 | Vcc        | 1.8V - 3.6V           |
 | Datasheet  | [Datasheet](https://ww1.microchip.com/downloads/en/DeviceDoc/SAMR34-R35-Low-Power-LoRa-Sub-GHz-SiP-Data-Sheet-DS70005356B.pdf) |
 | Board Manual | [SAM R34 XPro](https://www.microchip.com/en-us/development-tool/DM320111)<br>[WLR089 XPro](https://www.microchip.com/en-us/development-tool/EV23M25A)|
-
- */
diff --git a/boards/sensebox_samd21/doc.txt b/boards/sensebox_samd21/doc.md
similarity index 93%
rename from boards/sensebox_samd21/doc.txt
rename to boards/sensebox_samd21/doc.md
index 76dcbbf093..fc2811338f 100644
--- a/boards/sensebox_samd21/doc.txt
+++ b/boards/sensebox_samd21/doc.md
@@ -1,7 +1,6 @@
-/**
- * @defgroup    boards_sensebox_samd21 SenseBox MCU with SAMD21
- * @ingroup     boards
- * @brief       Support for the SenseBox MCU with SAMD21 board.
+@defgroup    boards_sensebox_samd21 SenseBox MCU with SAMD21
+@ingroup     boards
+@brief       Support for the SenseBox MCU with SAMD21 board.
 
 ### General information
 
@@ -66,4 +65,3 @@ This has the following limitations:
 - FSK mode is not possible
 - The interrupt pins can have different configurations, so caution is required
 when making changes.
- */