diff --git a/boards/olimex-msp430-h1611/doc.txt b/boards/olimex-msp430-h1611/doc.md
similarity index 99%
rename from boards/olimex-msp430-h1611/doc.txt
rename to boards/olimex-msp430-h1611/doc.md
index 551d1b60fc..318b1d9dd6 100644
--- a/boards/olimex-msp430-h1611/doc.txt
+++ b/boards/olimex-msp430-h1611/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_olimex_msp430_h1611 Olimex MSP430-H1611
 @ingroup     boards
 @brief       Support for the Olimex MSP430-H1611 board
@@ -93,5 +92,3 @@ TTL adapter    Olimex MSP430-H1611
        TXD --- 35 (P3.7)
        RXD --- 34 (P3.6)
 ```
-
- */
diff --git a/boards/olimex-msp430-h2618/doc.txt b/boards/olimex-msp430-h2618/doc.md
similarity index 99%
rename from boards/olimex-msp430-h2618/doc.txt
rename to boards/olimex-msp430-h2618/doc.md
index fc5634014d..97b54e331f 100644
--- a/boards/olimex-msp430-h2618/doc.txt
+++ b/boards/olimex-msp430-h2618/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_olimex_msp430_h2618 Olimex MSP430-H2618
 @ingroup     boards
 @brief       Support for the Olimex MSP430-H2618 board
@@ -107,5 +106,3 @@ TTL adapter    Olimex MSP430-H2618
        TXD --- 35 (P3.7)
        RXD --- 34 (P3.6)
 ```
-
- */
diff --git a/boards/olimexino-stm32/doc.txt b/boards/olimexino-stm32/doc.md
similarity index 99%
rename from boards/olimexino-stm32/doc.txt
rename to boards/olimexino-stm32/doc.md
index a73cf16c77..4570126b51 100644
--- a/boards/olimexino-stm32/doc.txt
+++ b/boards/olimexino-stm32/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_olimexino-stm32 STM32 Olimexino-stm32
 @ingroup     boards
 @brief       Support for the Olimexino STM32 board
@@ -64,4 +63,3 @@ USART1 is used for flashing the board whereas USART2 is the serial Output.
 
 ## Supported Toolchains
 For using the OLIMEXINO STM32 board you need to use ```arm-none-eabi```.
- */
diff --git a/boards/omote/doc.txt b/boards/omote/doc.md
similarity index 99%
rename from boards/omote/doc.txt
rename to boards/omote/doc.md
index 362dc9dbc5..4540cbe6d6 100644
--- a/boards/omote/doc.txt
+++ b/boards/omote/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_omote omote
 @ingroup     boards
 @brief       Support for the omote board
@@ -98,4 +97,3 @@ More Reading
 2. [CC2538 System-on-Chip Solution for 2.4-GHz IEEE 802.15.4 and ZigBee applications (SWRU319B)][cc2538]
 
 [cc2538]: http://www.ti.com/product/cc2538     "CC2538"
-*/
diff --git a/boards/opencm904/doc.txt b/boards/opencm904/doc.md
similarity index 93%
rename from boards/opencm904/doc.txt
rename to boards/opencm904/doc.md
index 86a9f03935..7e3b7ccd55 100644
--- a/boards/opencm904/doc.txt
+++ b/boards/opencm904/doc.md
@@ -1,5 +1,3 @@
-/**
 @defgroup    boards_opencm904 OpenCM9.04
 @ingroup     boards
 @brief       Support for the OpenCM9.04 board
- */
diff --git a/boards/openlabs-kw41z-mini-256kib/doc.txt b/boards/openlabs-kw41z-mini-256kib/doc.md
similarity index 99%
rename from boards/openlabs-kw41z-mini-256kib/doc.txt
rename to boards/openlabs-kw41z-mini-256kib/doc.md
index b09a68d642..6d8c1e3011 100644
--- a/boards/openlabs-kw41z-mini-256kib/doc.txt
+++ b/boards/openlabs-kw41z-mini-256kib/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_openlabs-kw41z-mini-256kib openlabs.co kw41z-mini-256kib board
 @ingroup     boards
 @brief       Support for openlabs-kw41z-mini (256kib Version)
@@ -18,5 +17,3 @@ microcontroller.
 
 ### M41W 9VT4 1N16S CTHHQP for the 512kiB version
 ![openlabs-kw41z-mini](https://user-images.githubusercontent.com/1301112/75628762-74478b80-5bdc-11ea-83ca-277e263867f6.jpg)
-
-*/
diff --git a/boards/openlabs-kw41z-mini/doc.txt b/boards/openlabs-kw41z-mini/doc.md
similarity index 99%
rename from boards/openlabs-kw41z-mini/doc.txt
rename to boards/openlabs-kw41z-mini/doc.md
index 18235110aa..1eeaf8800f 100644
--- a/boards/openlabs-kw41z-mini/doc.txt
+++ b/boards/openlabs-kw41z-mini/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_openlabs-kw41z-mini openlabs.co kw41z-mini board
 @ingroup     boards
 @brief       Support for openlabs-kw41z-mini
@@ -107,4 +106,3 @@ ADC input A3 needs a hack applied to `cpu/kinetis/periph/adc.c` to remove
 The PWM peripheral on this board isn't supported in the Kinetis PWM driver yet.
 
 Use external I2C pullup resistors if I2C is used.
- */
diff --git a/boards/openmote-b/doc.txt b/boards/openmote-b/doc.md
similarity index 99%
rename from boards/openmote-b/doc.txt
rename to boards/openmote-b/doc.md
index d0d49ccd6f..38ec72e40f 100644
--- a/boards/openmote-b/doc.txt
+++ b/boards/openmote-b/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_openmote-b OpenMote-b
 @ingroup     boards
 @brief       Support for the OpenMote-b board
@@ -67,4 +66,3 @@ The JTAG interface is required for debugging.  On some board revisions the
 debug may not be able to run. To debug use:
 
 `make debug`
- */
diff --git a/boards/openmote-cc2538/doc.txt b/boards/openmote-cc2538/doc.md
similarity index 99%
rename from boards/openmote-cc2538/doc.txt
rename to boards/openmote-cc2538/doc.md
index d1bd73edc7..66f6625ea9 100644
--- a/boards/openmote-cc2538/doc.txt
+++ b/boards/openmote-cc2538/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_openmote-cc2538 OpenMote-cc2538
 @ingroup     boards
 @brief       Support for the OpenMote-cc2538 board
@@ -57,4 +56,3 @@ from your application folder.
 
 macOS users may experiment a command line expecting `connect`. Just type it
 and the process will continue.
- */
diff --git a/boards/p-l496g-cell02/doc.txt b/boards/p-l496g-cell02/doc.md
similarity index 81%
rename from boards/p-l496g-cell02/doc.txt
rename to boards/p-l496g-cell02/doc.md
index cac814a672..41a8359d3f 100644
--- a/boards/p-l496g-cell02/doc.txt
+++ b/boards/p-l496g-cell02/doc.md
@@ -1,7 +1,6 @@
-/**
- * @defgroup    boards_p-l496g-cell02 ST P-L496G-CELL02
- * @ingroup     boards
- * @brief       Support for the ST P-L496G-CELL02 board
+@defgroup   boards_p-l496g-cell02 ST P-L496G-CELL02
+@ingroup    boards
+@brief      Support for the ST P-L496G-CELL02 board
 
 ## Overview
 
@@ -27,5 +26,3 @@ STDIO is available via the ST-Link programmer.
 Use the `term` target to open a terminal:
 
     make BOARD=p-l496g-cell02 -C examples/basic/hello-world term
-
- */
diff --git a/boards/p-nucleo-wb55/doc.txt b/boards/p-nucleo-wb55/doc.md
similarity index 99%
rename from boards/p-nucleo-wb55/doc.txt
rename to boards/p-nucleo-wb55/doc.md
index 580f06eac8..afb5cb4db1 100644
--- a/boards/p-nucleo-wb55/doc.txt
+++ b/boards/p-nucleo-wb55/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_p-nucleo-wb55 STM32 p-nucleo-wb55
 @ingroup     boards
 @brief       Support for the STM32 p-nucleo-wb55
@@ -126,5 +125,3 @@ make BOARD=p-nucleo-wb55 -C examples/basic/hello-world term
 |                   | USB               | yes       |            |
 |                   | PWM               | yes       | dev 0/4 ch |
 |                   | AES               | no        |            |
-
-*/
diff --git a/boards/pba-d-01-kw2x/doc.txt b/boards/pba-d-01-kw2x/doc.md
similarity index 99%
rename from boards/pba-d-01-kw2x/doc.txt
rename to boards/pba-d-01-kw2x/doc.md
index 7ab40b27e8..e563326278 100644
--- a/boards/pba-d-01-kw2x/doc.txt
+++ b/boards/pba-d-01-kw2x/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_pba-d-01-kw2x phyWAVE-KW22 Board
 @ingroup     boards
 @brief       Support for the phyWAVE evaluation board
@@ -87,4 +86,3 @@ The actual pin configuration of the board for RIOT can be found in
 | Light Sensor   | [TCS3772](https://ams.com/documents/20143/36005/TCS3772_DS000175_3-00.pdf/8689a345-f46b-d3f0-f839-eb8d38ead80d)   | yes       | [mainline](https://github.com/RIOT-OS/RIOT/pull/3135) |
 | IR-Termopile Sensor    | [TMP006](http://www.ti.com/ww/eu/sensampbook/tmp006.pdf)    |yes       | [mainline](https://github.com/RIOT-OS/RIOT/pull/2148) |
 | Capacitive Button  | PCB   | yes        | [mainline](https://github.com/RIOT-OS/RIOT/pull/7147) |
- */
diff --git a/boards/phynode-kw41z/doc.txt b/boards/phynode-kw41z/doc.md
similarity index 99%
rename from boards/phynode-kw41z/doc.txt
rename to boards/phynode-kw41z/doc.md
index adec71b5a2..4a43f65129 100644
--- a/boards/phynode-kw41z/doc.txt
+++ b/boards/phynode-kw41z/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_phynode-kw41z PhyNODE KW41Z
 @ingroup     boards
 @brief       Support for the Phytec PhyNODE KW41Z Board
@@ -41,5 +40,3 @@ digital gas sensor are supported. There's ongoing work on
 [IEEE802.15.4 radio support for KW41Z][radio-support]
 
 [radio-support]: https://github.com/RIOT-OS/RIOT/pull/7107
-
- */
diff --git a/boards/pinetime/doc.txt b/boards/pinetime/doc.md
similarity index 97%
rename from boards/pinetime/doc.txt
rename to boards/pinetime/doc.md
index 072258daa5..7b05ce5275 100644
--- a/boards/pinetime/doc.txt
+++ b/boards/pinetime/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_pinetime PineTime
 @ingroup     boards
 @brief       Support for the Pinetime
@@ -10,5 +9,3 @@ for an open source smartwatch in collaboration with wearable RTOS and Linux app
 developers & communities."
 
 See https://wiki.pine64.org/index.php/PineTime for more information.
-
- */
diff --git a/boards/pyboard/doc.txt b/boards/pyboard/doc.md
similarity index 98%
rename from boards/pyboard/doc.txt
rename to boards/pyboard/doc.md
index b1bac69102..71ac1397db 100644
--- a/boards/pyboard/doc.txt
+++ b/boards/pyboard/doc.md
@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_pyboard pyboard
 @ingroup     boards
 @brief       Support for the pyboard
@@ -28,5 +27,3 @@ In order to get serial output, connect an USB/serial adapter to USART1 RX/TX
 
 - unconnect 3.3v/DFU pin
 - reset again
-
- */