diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index a021e88..9694544 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -14,4 +14,4 @@ members = [
 [patch.crates-io]
 riscv-rt = { git = "https://github.com/rust-embedded/riscv-rt.git", rev = "e9bb7e0964aea781f1121cee82dd55098a4b43e8"}
 k210-pac = { git = "https://github.com/riscv-rust/k210-pac.git", rev = "e2473456cd72198867056b80d408ad0a40edb969"}
-k210-hal = { git = "https://github.com/riscv-rust/k210-hal.git", rev = "25c4e12af65f6e0d3e68c0c9227ad7f444f90e3e" }
+k210-hal = { git = "https://github.com/riscv-rust/k210-hal.git", rev = "b83e843c19a2f0bc4eb7f56322ae844818709298" }
diff --git a/rust/accelerometer/src/main.rs b/rust/accelerometer/src/main.rs
index 639929a..6c1a692 100644
--- a/rust/accelerometer/src/main.rs
+++ b/rust/accelerometer/src/main.rs
@@ -4,7 +4,7 @@
 #![no_std]
 #![no_main]
 
-use k210_hal::pac;
+use k210_hal::Peripherals;
 use k210_hal::prelude::*;
 use k210_hal::stdout::Stdout;
 use k210_shared::board::def::{io,DISP_WIDTH,DISP_HEIGHT,MSA300_SLV_ADDR,MSA300_ADDR_BITS,MSA300_CLK};
@@ -56,14 +56,14 @@ fn sample_cirle(x: i32, y: i32, cx: i32, cy: i32, r: i32, rr: i32) -> bool {
 
 #[entry]
 fn main() -> ! {
-    let p = pac::Peripherals::take().unwrap();
+    let p = Peripherals::take().unwrap();
 
     let clocks = k210_hal::clock::Clocks::new();
 
     usleep(200000);
 
     // Configure UART
-    let serial = p.UARTHS.constrain(115_200.bps(), &clocks);
+    let serial = p.UARTHS.configure((p.pins.pin5, p.pins.pin4), 115_200.bps(), &clocks);
     let (mut tx, _) = serial.split();
 
     let mut stdout = Stdout(&mut tx);
diff --git a/rust/dvp-ov/src/main.rs b/rust/dvp-ov/src/main.rs
index 9bed08d..14e678b 100644
--- a/rust/dvp-ov/src/main.rs
+++ b/rust/dvp-ov/src/main.rs
@@ -4,7 +4,7 @@
 #![no_std]
 #![no_main]
 
-use k210_hal::pac;
+use k210_hal::Peripherals;
 use k210_hal::prelude::*;
 use k210_hal::stdout::Stdout;
 use k210_shared::board::def::{io,DISP_WIDTH,DISP_HEIGHT};
@@ -58,13 +58,13 @@ fn io_init() {
 
 #[entry]
 fn main() -> ! {
-    let p = pac::Peripherals::take().unwrap();
+    let p = Peripherals::take().unwrap();
     let clocks = k210_hal::clock::Clocks::new();
 
     usleep(200000);
 
     // Configure UART
-    let serial = p.UARTHS.constrain(115_200.bps(), &clocks);
+    let serial = p.UARTHS.configure((p.pins.pin5, p.pins.pin4), 115_200.bps(), &clocks);
     let (mut tx, _) = serial.split();
 
     let mut stdout = Stdout(&mut tx);
diff --git a/rust/game-of-life/src/main.rs b/rust/game-of-life/src/main.rs
index df38220..5e3c031 100644
--- a/rust/game-of-life/src/main.rs
+++ b/rust/game-of-life/src/main.rs
@@ -4,7 +4,7 @@
 #![no_std]
 #![no_main]
 
-use k210_hal::pac;
+use k210_hal::Peripherals;
 use k210_hal::prelude::*;
 use k210_hal::stdout::Stdout;
 use k210_shared::board::def::{io,DISP_WIDTH,DISP_HEIGHT,NS2009_SLV_ADDR,NS2009_CAL,NS2009_ADDR_BITS,NS2009_CLK};
@@ -139,14 +139,14 @@ pub static BLOCK_SPRITE: [[u32; 4];8] = [
 
 #[entry]
 fn main() -> ! {
-    let p = pac::Peripherals::take().unwrap();
+    let p = Peripherals::take().unwrap();
 
     let clocks = k210_hal::clock::Clocks::new();
 
     usleep(200000);
 
     // Configure UART
-    let serial = p.UARTHS.constrain(115_200.bps(), &clocks);
+    let serial = p.UARTHS.configure((p.pins.pin5, p.pins.pin4), 115_200.bps(), &clocks);
     let (mut tx, _) = serial.split();
 
     let mut stdout = Stdout(&mut tx);
diff --git a/rust/glyph-mapping/src/main.rs b/rust/glyph-mapping/src/main.rs
index bd06e9c..da4b5bd 100644
--- a/rust/glyph-mapping/src/main.rs
+++ b/rust/glyph-mapping/src/main.rs
@@ -6,7 +6,7 @@
 
 use k210_console::console::{Console, ScreenImage};
 use k210_console::cp437_8x8::GLYPH_BY_FILL;
-use k210_hal::pac;
+use k210_hal::Peripherals;
 use k210_hal::prelude::*;
 use k210_hal::stdout::Stdout;
 use k210_shared::board::def::{io,DISP_WIDTH,DISP_HEIGHT};
@@ -68,13 +68,13 @@ fn io_init() {
 
 #[entry]
 fn main() -> ! {
-    let p = pac::Peripherals::take().unwrap();
+    let p = Peripherals::take().unwrap();
     let clocks = k210_hal::clock::Clocks::new();
 
     usleep(200000);
 
     // Configure UART
-    let serial = p.UARTHS.constrain(115_200.bps(), &clocks);
+    let serial = p.UARTHS.configure((p.pins.pin5, p.pins.pin4), 115_200.bps(), &clocks);
     let (mut tx, _) = serial.split();
 
     let mut stdout = Stdout(&mut tx);
diff --git a/rust/k210-console/src/main.rs b/rust/k210-console/src/main.rs
index bf5d5ee..43109c4 100644
--- a/rust/k210-console/src/main.rs
+++ b/rust/k210-console/src/main.rs
@@ -6,7 +6,7 @@
 
 mod lfsr;
 
-use k210_hal::pac;
+use k210_hal::Peripherals;
 use k210_hal::prelude::*;
 use k210_hal::stdout::Stdout;
 use k210_shared::board::def::io;
@@ -44,7 +44,7 @@ fn io_set_power() {
 
 #[entry]
 fn main() -> ! {
-    let p = pac::Peripherals::take().unwrap();
+    let p = Peripherals::take().unwrap();
 
     // Configure clocks (TODO)
     let clocks = k210_hal::clock::Clocks::new();
@@ -53,7 +53,7 @@ fn main() -> ! {
     usleep(200000);
 
     // Configure UART
-    let serial = p.UARTHS.constrain(115_200.bps(), &clocks);
+    let serial = p.UARTHS.configure((p.pins.pin5, p.pins.pin4), 115_200.bps(), &clocks);
     let (mut tx, _) = serial.split();
 
     let mut stdout = Stdout(&mut tx);
diff --git a/rust/k210-shared/src/panic.rs b/rust/k210-shared/src/panic.rs
index 9ed5aa9..b38915d 100644
--- a/rust/k210-shared/src/panic.rs
+++ b/rust/k210-shared/src/panic.rs
@@ -1,5 +1,5 @@
 /** Panic handler: based on ARM panic-itm */
-use k210_hal::pac;
+use k210_hal::Peripherals;
 use k210_hal::prelude::*;
 use k210_hal::stdout::Stdout;
 use core::panic::PanicInfo;
@@ -10,9 +10,9 @@ use core::sync::atomic::{self, Ordering};
 fn panic(info: &PanicInfo) -> ! {
     // Stealing all peripherals, re-initializing the clocks and serial seems overkill here, but
     // also, can we really know the state?
-    let p = unsafe { pac::Peripherals::steal() };
+    let p = unsafe { Peripherals::steal() };
     let clocks = k210_hal::clock::Clocks::new();
-    let serial = p.UARTHS.constrain(115_200.bps(), &clocks);
+    let serial = p.UARTHS.configure((p.pins.pin5, p.pins.pin4), 115_200.bps(), &clocks);
     let (mut tx, _) = serial.split();
     let mut stdout = Stdout(&mut tx);
     writeln!(stdout, "{}", info).unwrap();
diff --git a/rust/mandelbrot/src/main.rs b/rust/mandelbrot/src/main.rs
index be93e1a..0a80c74 100644
--- a/rust/mandelbrot/src/main.rs
+++ b/rust/mandelbrot/src/main.rs
@@ -6,7 +6,7 @@
 
 mod palette;
 
-use k210_hal::pac;
+use k210_hal::Peripherals;
 use k210_hal::prelude::*;
 use k210_hal::stdout::Stdout;
 use k210_shared::board::def::{io,DISP_WIDTH,DISP_HEIGHT};
@@ -53,7 +53,7 @@ fn mandelbrot(cx: f32, cy: f32, iterations: u32) -> u32 {
 
 #[entry]
 fn main() -> ! {
-    let p = pac::Peripherals::take().unwrap();
+    let p = Peripherals::take().unwrap();
 
     // Configure clocks (TODO)
     let clocks = k210_hal::clock::Clocks::new();
@@ -61,7 +61,7 @@ fn main() -> ! {
     usleep(200000);
 
     // Configure UART
-    let serial = p.UARTHS.constrain(115_200.bps(), &clocks);
+    let serial = p.UARTHS.configure((p.pins.pin5, p.pins.pin4), 115_200.bps(), &clocks);
     let (mut tx, _) = serial.split();
 
     let mut stdout = Stdout(&mut tx);
diff --git a/rust/rgbcontrol/src/main.rs b/rust/rgbcontrol/src/main.rs
index bbd0992..8ff50bb 100644
--- a/rust/rgbcontrol/src/main.rs
+++ b/rust/rgbcontrol/src/main.rs
@@ -5,7 +5,7 @@
 #![no_main]
 
 use core::cmp::{min,max};
-use k210_hal::pac;
+use k210_hal::Peripherals;
 use k210_hal::prelude::*;
 use k210_hal::stdout::Stdout;
 use k210_shared::board::def::{
@@ -67,12 +67,12 @@ fn color_from_xy(x: u16, y: u16, v: f32) -> (f32, f32, f32) {
 
 #[entry]
 fn main() -> ! {
-    let p = pac::Peripherals::take().unwrap();
+    let p = Peripherals::take().unwrap();
     let clocks = k210_hal::clock::Clocks::new();
 
     usleep(200000);
 
-    let serial = p.UARTHS.constrain(115_200.bps(), &clocks);
+    let serial = p.UARTHS.configure((p.pins.pin5, p.pins.pin4), 115_200.bps(), &clocks);
     let (mut tx, _) = serial.split();
     let mut stdout = Stdout(&mut tx);
 
diff --git a/rust/uart-passthrough/src/main.rs b/rust/uart-passthrough/src/main.rs
index 71f3666..ed8c1fa 100644
--- a/rust/uart-passthrough/src/main.rs
+++ b/rust/uart-passthrough/src/main.rs
@@ -4,8 +4,9 @@
 #![no_std]
 #![no_main]
 
-use k210_hal::pac;
+use k210_hal::Peripherals;
 use k210_hal::prelude::*;
+use k210_hal::serial::Serial;
 use k210_shared::board::def::io;
 use k210_shared::soc::fpioa;
 use k210_shared::soc::gpio;
@@ -19,23 +20,21 @@ const DEFAULT_BAUD: u32 = 115_200;
 
 #[entry]
 fn main() -> ! {
-    let p = pac::Peripherals::take().unwrap();
+    let p = Peripherals::take().unwrap();
     let clocks = k210_hal::clock::Clocks::new();
 
     // Configure UARTHS (→host)
-    let mut serial = p.UARTHS.constrain(DEFAULT_BAUD.bps(), &clocks);
+    let mut serial = p.UARTHS.configure((p.pins.pin5, p.pins.pin4), DEFAULT_BAUD.bps(), &clocks);
     let (mut tx, mut rx) = serial.split();
 
     // Configure UART1 (→WIFI)
     sysctl::clock_enable(sysctl::clock::UART1);
     sysctl::reset(sysctl::reset::UART1);
-    fpioa::set_function(io::WIFI_RX, fpioa::function::UART1_TX);
-    fpioa::set_function(io::WIFI_TX, fpioa::function::UART1_RX);
     fpioa::set_function(io::WIFI_EN, fpioa::function::GPIOHS8);
     fpioa::set_io_pull(io::WIFI_EN, fpioa::pull::DOWN);
     gpiohs::set_pin(8, true);
     gpiohs::set_direction(8, gpio::direction::OUTPUT);
-    let mut wifi_serial = p.UART1.constrain(DEFAULT_BAUD.bps(), &clocks);
+    let mut wifi_serial = p.UART1.configure((p.pins.pin7, p.pins.pin6), DEFAULT_BAUD.bps(), &clocks);
     let (mut wtx, mut wrx) = wifi_serial.split();
 
     // Relay characters between UARTs
@@ -44,7 +43,8 @@ fn main() -> ! {
             // OOB restores safe baudrate for UARTHS, to be sure we're able to recover from
             // sync failures
             let mut rate = DEFAULT_BAUD;
-            serial = rx.join(tx).free().constrain(rate.bps(), &clocks);
+            let (userial, pins) = Serial::join(tx, rx).free();
+            serial = userial.configure(pins, rate.bps(), &clocks);
             let s = serial.split();
             tx = s.0;
             rx = s.1;
@@ -55,8 +55,9 @@ fn main() -> ! {
                     d.iter_mut().for_each(|x| { *x = block!(rx.read()).unwrap() });
                     rate = (d[0] as u32) | ((d[1] as u32) << 8) | ((d[2] as u32) << 16) | ((d[3] as u32) << 24);
 
-                    // re-constrain UARTHS at new rate
-                    serial = rx.join(tx).free().constrain(rate.bps(), &clocks);
+                    // re-configure UARTHS at new rate
+                    let (userial, pins) = Serial::join(tx, rx).free();
+                    serial = userial.configure(pins, rate.bps(), &clocks);
                     let s = serial.split();
                     tx = s.0;
                     rx = s.1;
@@ -68,8 +69,9 @@ fn main() -> ! {
                 }
                 _ => {}
             }
-            // re-constrain UART1
-            wifi_serial = wrx.join(wtx).free().constrain(rate.bps(), &clocks);
+            // re-configure UART1
+            let (wifi_userial, wifi_pins) = Serial::join(wtx, wrx).free();
+            wifi_serial = wifi_userial.configure(wifi_pins, rate.bps(), &clocks);
             let s = wifi_serial.split();
             wtx = s.0;
             wrx = s.1;
diff --git a/rust/weather/src/main.rs b/rust/weather/src/main.rs
index d9694d7..2c97265 100644
--- a/rust/weather/src/main.rs
+++ b/rust/weather/src/main.rs
@@ -9,7 +9,7 @@ use embedded_hal::serial;
 use esp8266at::handler::{NetworkEvent, SerialNetworkHandler};
 use esp8266at::response::{parse, ConnectionType, ParseResult};
 use esp8266at::traits::{self, Write};
-use k210_hal::pac;
+use k210_hal::Peripherals;
 use k210_hal::prelude::*;
 use k210_hal::stdout::Stdout;
 use k210_shared::board::def::io;
@@ -82,27 +82,25 @@ fn io_init() {
 
 #[entry]
 fn main() -> ! {
-    let p = pac::Peripherals::take().unwrap();
+    let p = Peripherals::take().unwrap();
     let clocks = k210_hal::clock::Clocks::new();
 
     usleep(200000);
     io_init();
 
     // Configure UARTHS (→host)
-    let serial = p.UARTHS.constrain(DEFAULT_BAUD.bps(), &clocks);
+    let serial = p.UARTHS.configure((p.pins.pin5, p.pins.pin4), DEFAULT_BAUD.bps(), &clocks);
     let (mut tx, mut _rx) = serial.split();
     let mut debug = Stdout(&mut tx);
 
     // Configure UART1 (→WIFI)
     sysctl::clock_enable(sysctl::clock::UART1);
     sysctl::reset(sysctl::reset::UART1);
-    fpioa::set_function(io::WIFI_RX, fpioa::function::UART1_TX);
-    fpioa::set_function(io::WIFI_TX, fpioa::function::UART1_RX);
     fpioa::set_function(io::WIFI_EN, fpioa::function::GPIOHS8);
     fpioa::set_io_pull(io::WIFI_EN, fpioa::pull::DOWN);
     gpiohs::set_pin(8, true);
     gpiohs::set_direction(8, gpio::direction::OUTPUT);
-    let wifi_serial = p.UART1.constrain(DEFAULT_BAUD.bps(), &clocks);
+    let wifi_serial = p.UART1.configure((p.pins.pin7, p.pins.pin6), DEFAULT_BAUD.bps(), &clocks);
     let (mut wtx, mut wrx) = wifi_serial.split();
 
     let mut wa = WriteAdapter::new(&mut wtx);