diff --git a/src/utils/def_generated.pl b/src/utils/def_generated.pl
new file mode 100644
index 0000000000..39413037d5
--- /dev/null
+++ b/src/utils/def_generated.pl
@@ -0,0 +1,160 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+
+# This sript will generate templated files for peripherals
+
+# io_def_generated.h
+
+my @ports = ('A', 'B', 'C', 'D', 'E', 'F', 'G');
+my @pins  = 0 .. 15;
+my @timers = (1,2,3,4,6,7,8,15,16,17);
+my $drivers_dir = "../main/drivers";
+
+# change list separator to newline - we use @{} interpolation to merge multiline strings
+$" = "\n";
+
+chomp(my $disclaimer_generated = <<"END");
+// this file is automatically generated by src/utils/def_generated.pl script
+// do not modify this file directly, your changes will be lost
+END
+
+my $io_def_file="$drivers_dir/io_def_generated.h";
+my $fh;
+open $fh, '>', $io_def_file or die "Cannot open $io_def_file: $!";
+print { $fh} <<"END" or die  "Cannot write into $io_def_file: $!"; close $fh;
+#pragma once
+${disclaimer_generated}
+
+// DEFIO_PORT_<port>_USED_MASK is bitmask of used pins on target
+// DEFIO_PORT_<port>_USED_COUNT is count of used pins on target
+
+@{[do {
+    my @prev_ports = ();
+    map { my $port = $_;  my $ret = << "END2"; push @prev_ports, $port; $ret } @ports; }]}
+#if defined(TARGET_IO_PORT${port})
+# define DEFIO_PORT_${port}_USED_MASK TARGET_IO_PORT${port}
+# define DEFIO_PORT_${port}_USED_COUNT BITCOUNT(DEFIO_PORT_${port}_USED_MASK)
+#else
+# define DEFIO_PORT_${port}_USED_MASK 0
+# define DEFIO_PORT_${port}_USED_COUNT 0
+#endif
+# define DEFIO_PORT_${port}_OFFSET (@{[join('+', map {  "DEFIO_PORT_${_}_USED_COUNT" } @prev_ports) || '0']})
+END2
+
+
+// DEFIO_GPIOID__<port> maps to port index
+@{[ map { my $port = $_; chomp(my $ret = << "END2"); $ret } @ports ]}
+#define DEFIO_GPIOID__${port} @{[ord($port)-ord('A')]}
+END2
+
+// DEFIO_TAG__P<port><pin> will expand to TAG if defined for target
+// DEFIO_REC__P<port><pin> will expand to ioRec* (using DEFIO_REC_INDEX(idx))
+// all P<port><pin> macros are defined to expand to self to generate warning if someone tries to redefine them
+@{[do {
+    my @prev_ports = ();
+    map { my $port = $_;  my @ret = map { my $pin = $_; chomp(my $ret = << "END2"); $ret } @pins ; push @prev_ports, $port; @ret } @ports; }]}
+#define P${port}${pin} P${port}${pin}
+#if DEFIO_PORT_${port}_USED_MASK & BIT(${pin})
+# define DEFIO_TAG__P${port}${pin} DEFIO_TAG_MAKE(DEFIO_GPIOID__${port}, ${pin})
+# define DEFIO_REC__P${port}${pin} DEFIO_REC_INDEXED(BITCOUNT(DEFIO_PORT_${port}_USED_MASK & (BIT(${pin}) - 1)) + @{[join('+', map {  "DEFIO_PORT_${_}_USED_COUNT" } @prev_ports) || '0']})
+#else
+# define DEFIO_TAG__P${port}${pin} defio_error_P${port}${pin}_is_not_supported_on_TARGET
+# define DEFIO_REC__P${port}${pin} defio_error_P${port}${pin}_is_not_supported_on_TARGET
+#endif
+END2
+
+// DEFIO_IO_USED_COUNT is number of io pins supported on target
+#define DEFIO_IO_USED_COUNT (@{[join('+', map {  "DEFIO_PORT_${_}_USED_COUNT" } @ports) || '0']})
+
+// DEFIO_PORT_USED_LIST - comma separated list of bitmask for all used ports.
+// DEFIO_PORT_OFFSET_LIST - comma separated list of port offsets (count of pins before this port)
+// unused ports on end of list are skipped
+@{[do {
+    my @used_ports = @ports;
+    map { my $port = $_; chomp(my $ret = << "END2"); @used_ports = grep {$_ ne $port} @used_ports; $ret } reverse(@ports) }]}
+#if !defined DEFIO_PORT_USED_LIST && DEFIO_PORT_${port}_USED_COUNT > 0
+# define DEFIO_PORT_USED_COUNT @{[scalar @used_ports]}
+# define DEFIO_PORT_USED_LIST @{[join(',', map { "DEFIO_PORT_${_}_USED_MASK" } @used_ports)]}
+# define DEFIO_PORT_OFFSET_LIST @{[join(',', map { "DEFIO_PORT_${_}_OFFSET" } @used_ports)]}
+#endif
+END2
+
+#if !defined(DEFIO_PORT_USED_LIST) && !defined(UNIT_TEST)
+# warning "No pins are defined. Maybe you forgot to define TARGET_IO_PORTx in target.h"
+# define DEFIO_PORT_USED_COUNT 0
+# define DEFIO_PORT_USED_LIST /* empty */
+# define DEFIO_PORT_OFFSET_LIST /* empty */
+#endif
+
+END
+
+exit; # only IO code is merged now
+
+my $timer_def_file="$drivers_dir/timer_def_generated.h";
+open $fh, '>', $timer_def_file or die "Cannot open $timer_def_file: $!";
+print { $fh} <<"END" or die  "Cannot write into $timer_def_file: $!"; close $fh;
+#pragma once
+${disclaimer_generated}
+
+// make sure macros for all timers are defined
+@{[ map { my $timer = $_; chomp(my $ret = << "END2"); $ret } @timers ]}
+#ifndef TARGET_TIMER_TIM${timer}
+# define TARGET_TIMER_TIM${timer} -1
+#endif
+END2
+
+// generate mask with used timers
+@{[do {
+     my @prev_timers = ();
+     map { my $timer = $_; chomp(my $ret = << "END2"); push @prev_timers, $timer; $ret } @timers }]}
+#if TARGET_TIMER_TIM${timer} > 0
+# define TARGET_TIMER_TIM${timer}_BIT BIT(${timer})
+# define TARGET_TIMER_TIM${timer}_INDEX  ( @{[ join("+", map("(TARGET_TIMER_TIM${_} >= 0)", @prev_timers)) || 0 ]} )
+#else
+# define TARGET_TIMER_TIM${timer}_BIT 0
+# define TARGET_TIMER_TIM${timer}_INDEX deftimer_error_TIMER${timer}_is_not_enabled_on_target
+#endif
+END2
+#define TIMER_USED_BITS  ( @{[ join "|", map("TARGET_TIMER_TIM${_}_BIT", @timers) ]} )
+#define TIMER_USED_COUNT ( @{[ join "+", map("(TARGET_TIMER_TIM${_} >= 0)", @timers) ]} )
+
+// structure to hold all timerRec_t.
+// Number of channels per timer is user specifed, structure will ensure correct packing
+struct timerRec_all {
+@{[ map { my $timer = $_; chomp(my $ret = << "END2"); $ret } @timers ]}
+#if TARGET_TIMER_TIM${timer} >= 0
+    timerRec_t rec_TIM${timer};
+# if TARGET_TIMER_TIM${timer} > 0
+    timerChRec_t rec_TIM${timer}_ch[TARGET_TIMER_TIM${timer}];
+# endif
+#endif
+END2
+};
+END
+
+my $timer_inc_file="$drivers_dir/timer_c_generated.inc";
+open $fh, '>', $timer_inc_file or die "Cannot open $timer_inc_file: $!";
+print { $fh} <<"END" or die  "Cannot write into $timer_inc_file: $!"; close $fh;
+${disclaimer_generated}
+
+// this code is included into timer.c file
+
+const timerDef_t timerDefs[] = {
+@{[ map { my $timer = $_; chomp(my $ret = << "END2"); $ret } @timers ]}
+#if TARGET_TIMER_TIM${timer} >= 0
+       DEF_TIMER_DEFINE(${timer}),
+#endif
+END2
+};
+
+timerRec_t* const timerRecPtrs[] = {
+@{[ map { my $timer = $_; chomp(my $ret = << "END2"); $ret } @timers ]}
+#if TARGET_TIMER_TIM${timer} >= 0
+       &timerRecs.rec_TIM${timer},
+#endif
+END2
+NULL    // terminate the list
+};
+END
+