diff --git a/extmod/modos.c b/extmod/modos.c
index 69fdc3fac0..b1dd267f88 100644
--- a/extmod/modos.c
+++ b/extmod/modos.c
@@ -145,6 +145,18 @@ static mp_obj_t mp_os_dupterm_notify(mp_obj_t obj_in) {
 static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_dupterm_notify_obj, mp_os_dupterm_notify);
 #endif
 
+#if MICROPY_PY_OS_URANDOM
+// This wraps the port-specific mp_hal_get_random(), which is usually defined in mphalport.c.
+static mp_obj_t mp_os_urandom(mp_obj_t num) {
+    mp_int_t n = mp_obj_get_int(num);
+    vstr_t vstr;
+    vstr_init_len(&vstr, n);
+    mp_hal_get_random(n, (uint8_t *)vstr.buf);
+    return mp_obj_new_bytes_from_vstr(&vstr);
+}
+static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
+#endif
+
 static const mp_rom_map_elem_t os_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_os) },
 
diff --git a/ports/alif/modos.c b/ports/alif/modos.c
deleted file mode 100644
index 9c8c84268c..0000000000
--- a/ports/alif/modos.c
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- * This file is part of the MicroPython project, http://micropython.org/
- *
- * The MIT License (MIT)
- *
- * Copyright (c) 2024 OpenMV LLC.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-#include "py/runtime.h"
-#include "se_services.h"
-
-#if MICROPY_PY_OS_URANDOM
-static mp_obj_t mp_os_urandom(mp_obj_t num) {
-    mp_int_t n = mp_obj_get_int(num);
-    vstr_t vstr;
-    vstr_init_len(&vstr, n);
-    uint64_t rnd = 0;
-    size_t rnd_bits = 0;
-    for (int i = 0; i < n; i++) {
-        if (rnd_bits == 0) {
-            rnd = se_services_rand64();
-            rnd_bits = 64;
-        }
-        vstr.buf[i] = rnd;
-        rnd >>= 8;
-        rnd_bits -= 8;
-    }
-    return mp_obj_new_bytes_from_vstr(&vstr);
-}
-static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
-#endif
diff --git a/ports/alif/mpconfigport.h b/ports/alif/mpconfigport.h
index 34214a3f7d..1561afd21f 100644
--- a/ports/alif/mpconfigport.h
+++ b/ports/alif/mpconfigport.h
@@ -113,7 +113,6 @@
 
 // Extended modules
 #define MICROPY_EPOCH_IS_1970                   (1)
-#define MICROPY_PY_OS_INCLUDEFILE               "ports/alif/modos.c"
 #define MICROPY_PY_OS_DUPTERM                   (1)
 #define MICROPY_PY_OS_SEP                       (1)
 #define MICROPY_PY_OS_SYNC                      (1)
diff --git a/ports/alif/mphalport.c b/ports/alif/mphalport.c
index 3bf8bb0aed..04e21aa257 100644
--- a/ports/alif/mphalport.c
+++ b/ports/alif/mphalport.c
@@ -269,3 +269,17 @@ void mp_hal_get_mac_ascii(int idx, size_t chr_off, size_t chr_len, char *dest) {
         *dest++ = hexchr[mac[chr_off >> 1] >> (4 * (1 - (chr_off & 1))) & 0xf];
     }
 }
+
+void mp_hal_get_random(size_t n, uint8_t *buf) {
+    uint64_t rnd = 0;
+    size_t rnd_bits = 0;
+    for (int i = 0; i < n; i++) {
+        if (rnd_bits == 0) {
+            rnd = se_services_rand64();
+            rnd_bits = 64;
+        }
+        buf[i] = rnd;
+        rnd >>= 8;
+        rnd_bits -= 8;
+    }
+}
diff --git a/ports/alif/mphalport.h b/ports/alif/mphalport.h
index 731ac14fc5..c90cbc1664 100644
--- a/ports/alif/mphalport.h
+++ b/ports/alif/mphalport.h
@@ -375,3 +375,5 @@ void mp_hal_get_mac(int idx, uint8_t buf[6]);
 void mp_hal_get_mac_ascii(int idx, size_t chr_off, size_t chr_len, char *dest);
 
 uint32_t mp_hal_time_get(uint32_t *microseconds);
+
+void mp_hal_get_random(size_t n, uint8_t *buf);
diff --git a/ports/cc3200/hal/cc3200_hal.c b/ports/cc3200/hal/cc3200_hal.c
index e149968a51..cc2cd66624 100644
--- a/ports/cc3200/hal/cc3200_hal.c
+++ b/ports/cc3200/hal/cc3200_hal.c
@@ -49,6 +49,7 @@
 #include "telnet.h"
 #include "pybuart.h"
 #include "utils.h"
+#include "random.h"
 
 #ifdef USE_FREERTOS
 #include "FreeRTOS.h"
@@ -168,6 +169,13 @@ int mp_hal_stdin_rx_chr(void) {
     }
 }
 
+// Fill buf with n random bytes, generated by the hardware random number generator.
+void mp_hal_get_random(size_t n, uint8_t *buf) {
+    for (int i = 0; i < n; i++) {
+        buf[i] = rng_get();
+    }
+}
+
 /******************************************************************************
  DEFINE PRIVATE FUNCTIONS
  ******************************************************************************/
diff --git a/ports/cc3200/hal/cc3200_hal.h b/ports/cc3200/hal/cc3200_hal.h
index d07a9a1703..72d2915848 100644
--- a/ports/cc3200/hal/cc3200_hal.h
+++ b/ports/cc3200/hal/cc3200_hal.h
@@ -75,3 +75,5 @@ extern void mp_hal_set_interrupt_char (int c);
 #define mp_hal_delay_us(usec) UtilsDelay(UTILS_DELAY_US_TO_COUNT(usec))
 #define mp_hal_ticks_cpu() (SysTickPeriodGet() - SysTickValueGet())
 #define mp_hal_time_ns() (0) // not implemented
+
+void mp_hal_get_random(size_t n, uint8_t *buf);
diff --git a/ports/cc3200/mods/modos.c b/ports/cc3200/mods/modos.c
deleted file mode 100644
index 8c22ad8daf..0000000000
--- a/ports/cc3200/mods/modos.c
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * This file is part of the MicroPython project, http://micropython.org/
- *
- * The MIT License (MIT)
- *
- * Copyright (c) 2013-2023 Damien P. George
- * Copyright (c) 2015 Daniel Campora
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-// This file is never compiled standalone, it's included directly from
-// extmod/modos.c via MICROPY_PY_OS_INCLUDEFILE.
-
-#include "py/runtime.h"
-#include "random.h"
-
-static mp_obj_t mp_os_urandom(mp_obj_t num) {
-    mp_int_t n = mp_obj_get_int(num);
-    vstr_t vstr;
-    vstr_init_len(&vstr, n);
-    for (int i = 0; i < n; i++) {
-        vstr.buf[i] = rng_get();
-    }
-    return mp_obj_new_bytes_from_vstr(&vstr);
-}
-static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
diff --git a/ports/cc3200/mpconfigport.h b/ports/cc3200/mpconfigport.h
index 38e766121e..f2a00b8300 100644
--- a/ports/cc3200/mpconfigport.h
+++ b/ports/cc3200/mpconfigport.h
@@ -95,7 +95,6 @@
 #define MICROPY_PY_JSON                             (1)
 #define MICROPY_PY_RE                               (1)
 #define MICROPY_PY_OS                               (1)
-#define MICROPY_PY_OS_INCLUDEFILE                   "ports/cc3200/mods/modos.c"
 #define MICROPY_PY_OS_DUPTERM                       (1)
 #define MICROPY_PY_OS_SYNC                          (1)
 #define MICROPY_PY_OS_URANDOM                       (1)
diff --git a/ports/esp32/modos.c b/ports/esp32/modos.c
deleted file mode 100644
index d5ba611e88..0000000000
--- a/ports/esp32/modos.c
+++ /dev/null
@@ -1,53 +0,0 @@
-/*
- * This file is part of the MicroPython project, http://micropython.org/
- *
- * Development of the code in this file was sponsored by Microbric Pty Ltd
- *
- * The MIT License (MIT)
- *
- * Copyright (c) 2015 Josef Gajdusek
- * Copyright (c) 2016 Damien P. George
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-// This file is never compiled standalone, it's included directly from
-// extmod/modos.c via MICROPY_PY_OS_INCLUDEFILE.
-
-#include "esp_system.h"
-
-#include "py/runtime.h"
-#include "py/mphal.h"
-#include "extmod/misc.h"
-
-static mp_obj_t mp_os_urandom(mp_obj_t num) {
-    mp_int_t n = mp_obj_get_int(num);
-    vstr_t vstr;
-    vstr_init_len(&vstr, n);
-    uint32_t r = 0;
-    for (int i = 0; i < n; i++) {
-        if ((i & 3) == 0) {
-            r = esp_random(); // returns 32-bit hardware random number
-        }
-        vstr.buf[i] = r;
-        r >>= 8;
-    }
-    return mp_obj_new_bytes_from_vstr(&vstr);
-}
-static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
diff --git a/ports/esp32/mpconfigport.h b/ports/esp32/mpconfigport.h
index a22b91ed3d..dd8f89c4bc 100644
--- a/ports/esp32/mpconfigport.h
+++ b/ports/esp32/mpconfigport.h
@@ -111,7 +111,6 @@
 #endif // MICROPY_PY_BLUETOOTH
 
 #define MICROPY_PY_RANDOM_SEED_INIT_FUNC    (esp_random())
-#define MICROPY_PY_OS_INCLUDEFILE           "ports/esp32/modos.c"
 #define MICROPY_PY_OS_DUPTERM               (1)
 #define MICROPY_PY_OS_DUPTERM_NOTIFY        (1)
 #define MICROPY_PY_OS_SYNC                  (1)
diff --git a/ports/esp32/mphalport.c b/ports/esp32/mphalport.c
index 7156895af3..a0a3860f49 100644
--- a/ports/esp32/mphalport.c
+++ b/ports/esp32/mphalport.c
@@ -272,3 +272,14 @@ void mp_hal_wake_main_task_from_isr(void) {
         portYIELD_FROM_ISR();
     }
 }
+
+void mp_hal_get_random(size_t n, uint8_t *buf) {
+    uint32_t r = 0;
+    for (int i = 0; i < n; i++) {
+        if ((i & 3) == 0) {
+            r = esp_random(); // returns 32-bit hardware random number
+        }
+        buf[i] = r;
+        r >>= 8;
+    }
+}
diff --git a/ports/esp32/mphalport.h b/ports/esp32/mphalport.h
index a2b11520a5..daacedad69 100644
--- a/ports/esp32/mphalport.h
+++ b/ports/esp32/mphalport.h
@@ -155,4 +155,6 @@ static inline void mp_hal_pin_write(mp_hal_pin_obj_t pin, int v) {
 
 spi_host_device_t machine_hw_spi_get_host(mp_obj_t in);
 
+void mp_hal_get_random(size_t n, uint8_t *buf);
+
 #endif // INCLUDED_MPHALPORT_H
diff --git a/ports/esp8266/esp_mphal.c b/ports/esp8266/esp_mphal.c
index 3f03c55800..264b1c9441 100644
--- a/ports/esp8266/esp_mphal.c
+++ b/ports/esp8266/esp_mphal.c
@@ -176,3 +176,10 @@ int ets_esf_free_bufs(int idx) {
     }
     return cnt;
 }
+
+// Fill buf with n random bytes, generated by the hardware random number generator.
+void mp_hal_get_random(size_t n, uint8_t *buf) {
+    for (int i = 0; i < n; i++) {
+        buf[i] = *WDEV_HWRNG;
+    }
+}
diff --git a/ports/esp8266/esp_mphal.h b/ports/esp8266/esp_mphal.h
index 6d2844e37d..7ea00a175a 100644
--- a/ports/esp8266/esp_mphal.h
+++ b/ports/esp8266/esp_mphal.h
@@ -120,3 +120,5 @@ static inline int mp_hal_pin_read_output(mp_hal_pin_obj_t pin) {
 
 void *ets_get_esf_buf_ctlblk(void);
 int ets_esf_free_bufs(int idx);
+
+void mp_hal_get_random(size_t n, uint8_t *buf);
diff --git a/ports/esp8266/modos.c b/ports/esp8266/modos.c
index 8149c087fd..c77430bfdd 100644
--- a/ports/esp8266/modos.c
+++ b/ports/esp8266/modos.c
@@ -35,17 +35,6 @@ static const char *mp_os_uname_release(void) {
     return system_get_sdk_version();
 }
 
-static mp_obj_t mp_os_urandom(mp_obj_t num) {
-    mp_int_t n = mp_obj_get_int(num);
-    vstr_t vstr;
-    vstr_init_len(&vstr, n);
-    for (int i = 0; i < n; i++) {
-        vstr.buf[i] = *WDEV_HWRNG;
-    }
-    return mp_obj_new_bytes_from_vstr(&vstr);
-}
-static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
-
 void mp_os_dupterm_stream_detached_attached(mp_obj_t stream_detached, mp_obj_t stream_attached) {
     if (mp_obj_get_type(stream_attached) == &machine_uart_type) {
         ++uart_attached_to_dupterm;
diff --git a/ports/mimxrt/mbedtls/mbedtls_port.c b/ports/mimxrt/mbedtls/mbedtls_port.c
index fa2d81001b..dbc84bacfe 100644
--- a/ports/mimxrt/mbedtls/mbedtls_port.c
+++ b/ports/mimxrt/mbedtls/mbedtls_port.c
@@ -25,6 +25,7 @@
  */
 
 #include "py/runtime.h"
+#include "mphalport.h"
 
 #ifdef MICROPY_SSL_MBEDTLS
 
@@ -35,13 +36,9 @@
 #include "mbedtls/platform_time.h"
 #endif
 
-void trng_random_data(unsigned char *output, size_t len);
-
 int mbedtls_hardware_poll(void *data, unsigned char *output, size_t len, size_t *olen) {
-
-    // assumes that TRNG_Init was called during startup
     *olen = len;
-    trng_random_data(output, len);
+    mp_hal_get_random(len, output);
 
     return 0;
 }
diff --git a/ports/mimxrt/modos.c b/ports/mimxrt/modos.c
index 0eb32afba3..1f26b7166f 100644
--- a/ports/mimxrt/modos.c
+++ b/ports/mimxrt/modos.c
@@ -63,9 +63,9 @@ static void trng_start(void) {
     }
 }
 
-void trng_random_data(unsigned char *output, size_t len) {
+void mp_hal_get_random(size_t n, uint8_t *buf) {
     trng_start();
-    CAAM_RNG_GetRandomData(CAAM, &caam_handle, caam_state_handle, output, len,
+    CAAM_RNG_GetRandomData(CAAM, &caam_handle, caam_state_handle, buf, n,
         kCAAM_RngDataAny, NULL);
 }
 
@@ -83,9 +83,9 @@ static void trng_start(void) {
     }
 }
 
-void trng_random_data(unsigned char *output, size_t len) {
+void mp_hal_get_random(size_t n, uint8_t *buf) {
     trng_start();
-    TRNG_GetRandomData(TRNG, output, len);
+    TRNG_GetRandomData(TRNG, buf, n);
 }
 
 #endif
@@ -94,20 +94,6 @@ uint32_t trng_random_u32(void) {
     uint32_t rngval;
 
     trng_start();
-    trng_random_data((uint8_t *)&rngval, 4);
+    mp_hal_get_random(4, (uint8_t *)&rngval);
     return rngval;
 }
-
-#if MICROPY_PY_OS_URANDOM
-static mp_obj_t mp_os_urandom(mp_obj_t num) {
-    mp_int_t n = mp_obj_get_int(num);
-    vstr_t vstr;
-    vstr_init_len(&vstr, n);
-
-    trng_start();
-    trng_random_data((uint8_t *)vstr.buf, n);
-
-    return mp_obj_new_bytes_from_vstr(&vstr);
-}
-static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
-#endif
diff --git a/ports/mimxrt/mphalport.h b/ports/mimxrt/mphalport.h
index a0e4575024..a3ce4cbc48 100644
--- a/ports/mimxrt/mphalport.h
+++ b/ports/mimxrt/mphalport.h
@@ -159,5 +159,6 @@ void mp_hal_generate_laa_mac(int idx, uint8_t buf[6]);
 void mp_hal_get_mac(int idx, uint8_t buf[6]);
 void mp_hal_get_mac_ascii(int idx, size_t chr_off, size_t chr_len, char *dest);
 void mp_hal_get_unique_id(uint8_t id[]);
+void mp_hal_get_random(size_t n, uint8_t *buf);
 
 #endif // MICROPY_INCLUDED_MIMXRT_MPHALPORT_H
diff --git a/ports/nrf/modules/os/modos.c b/ports/nrf/modules/os/modos.c
index 97ed1e1bad..e2ba0ddfed 100644
--- a/ports/nrf/modules/os/modos.c
+++ b/ports/nrf/modules/os/modos.c
@@ -29,23 +29,8 @@
 
 #include "py/runtime.h"
 #include "extmod/modmachine.h"
-#include "drivers/rng.h"
 #include "modules/machine/uart.h"
 
-#if MICROPY_PY_OS_URANDOM
-// Return a bytes object with n random bytes, generated by the hardware random number generator.
-static mp_obj_t mp_os_urandom(mp_obj_t num) {
-    mp_int_t n = mp_obj_get_int(num);
-    vstr_t vstr;
-    vstr_init_len(&vstr, n);
-    for (int i = 0; i < n; i++) {
-        vstr.buf[i] = (uint8_t)(rng_generate_random_word() & 0xFF);
-    }
-    return mp_obj_new_bytes_from_vstr(&vstr);
-}
-static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
-#endif
-
 #if MICROPY_PY_OS_DUPTERM
 void mp_os_dupterm_stream_detached_attached(mp_obj_t stream_detached, mp_obj_t stream_attached) {
     #if MICROPY_PY_MACHINE_UART
diff --git a/ports/nrf/mphalport.c b/ports/nrf/mphalport.c
index 3a3d3ad7a6..faeee9aae5 100644
--- a/ports/nrf/mphalport.c
+++ b/ports/nrf/mphalport.c
@@ -38,6 +38,7 @@
 #include "nrfx_config.h"
 #include "drivers/bluetooth/ble_uart.h"
 #include "shared/tinyusb/mp_usbd_cdc.h"
+#include "drivers/rng.h"
 
 #if MICROPY_PY_TIME_TICKS
 #include "nrfx_rtc.h"
@@ -281,6 +282,12 @@ mp_uint_t mp_hal_stdout_tx_strn(const char *str, mp_uint_t len) {
     return did_write ? ret : 0;
 }
 
+void mp_hal_get_random(size_t n, uint8_t *buf) {
+    for (int i = 0; i < n; i++) {
+        buf[i] = (uint8_t)(rng_generate_random_word() & 0xFF);
+    }
+}
+
 #if MICROPY_PY_TIME_TICKS
 
 void mp_hal_delay_us(mp_uint_t us) {
diff --git a/ports/nrf/mphalport.h b/ports/nrf/mphalport.h
index 12e881d7b6..60c651839e 100644
--- a/ports/nrf/mphalport.h
+++ b/ports/nrf/mphalport.h
@@ -80,6 +80,8 @@ const char *nrfx_error_code_lookup(uint32_t err_code);
 
 void mp_nrf_start_lfclk(void);
 
+void mp_hal_get_random(size_t n, uint8_t *buf);
+
 #define MP_HAL_PIN_FMT           "%q"
 #define mp_hal_pin_obj_t const pin_obj_t *
 #define mp_hal_get_pin_obj(o)    pin_find(o)
diff --git a/ports/qemu/mphalport.c b/ports/qemu/mphalport.c
index a4fa32e297..36175815ec 100644
--- a/ports/qemu/mphalport.c
+++ b/ports/qemu/mphalport.c
@@ -101,3 +101,12 @@ void mp_hal_delay_us(mp_uint_t us) {
 mp_uint_t mp_hal_ticks_cpu(void) {
     return 0;
 }
+
+// Provide a dummy version of mp_hal_get_random() using a LCG
+static uint32_t random_state;
+void mp_hal_get_random(size_t n, uint8_t *buf) {
+    for (size_t i = 0; i < n; ++i) {
+        random_state = random_state * 1664525 + 1013904223;
+        buf[i] = random_state >> 24;
+    }
+}
diff --git a/ports/qemu/mphalport.h b/ports/qemu/mphalport.h
index 9355107495..49f14fc884 100644
--- a/ports/qemu/mphalport.h
+++ b/ports/qemu/mphalport.h
@@ -26,3 +26,5 @@
 
 #include <stddef.h>
 #include "shared/runtime/interrupt_char.h"
+
+void mp_hal_get_random(size_t n, uint8_t *buf);
diff --git a/ports/renesas-ra/modos.c b/ports/renesas-ra/modos.c
index 2051e9420f..f8ee9cd8ee 100644
--- a/ports/renesas-ra/modos.c
+++ b/ports/renesas-ra/modos.c
@@ -28,7 +28,6 @@
 #include "py/runtime.h"
 #include "extmod/modmachine.h"
 #include "uart.h"
-#include "rng.h"
 
 bool mp_os_dupterm_is_builtin_stream(mp_const_obj_t stream) {
     const mp_obj_type_t *type = mp_obj_get_type(stream);
@@ -44,16 +43,3 @@ void mp_os_dupterm_stream_detached_attached(mp_obj_t stream_detached, mp_obj_t s
         uart_attach_to_repl(MP_OBJ_TO_PTR(stream_attached), true);
     }
 }
-
-#if MICROPY_PY_OS_URANDOM
-static mp_obj_t mp_os_urandom(mp_obj_t num) {
-    mp_int_t n = mp_obj_get_int(num);
-    vstr_t vstr;
-    vstr_init_len(&vstr, n);
-    for (int i = 0; i < n; i++) {
-        vstr.buf[i] = rng_read();
-    }
-    return mp_obj_new_bytes_from_vstr(&vstr);
-}
-static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
-#endif
diff --git a/ports/renesas-ra/mphalport.c b/ports/renesas-ra/mphalport.c
index 455b28af19..35d71f04b9 100644
--- a/ports/renesas-ra/mphalport.c
+++ b/ports/renesas-ra/mphalport.c
@@ -37,6 +37,7 @@
 #include "shared/tinyusb/mp_usbd_cdc.h"
 #include "tusb.h"
 #include "uart.h"
+#include "rng.h"
 
 #if MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE
 void flash_cache_commit(void);
@@ -173,6 +174,14 @@ void mp_hal_get_mac_ascii(int idx, size_t chr_off, size_t chr_len, char *dest) {
     }
 }
 
+#if MICROPY_HW_ENABLE_RNG
+void mp_hal_get_random(size_t n, uint8_t *buf) {
+    for (int i = 0; i < n; i++) {
+        buf[i] = rng_read();
+    }
+}
+#endif
+
 #if MICROPY_HW_ENABLE_USBDEV
 void usbfs_interrupt_handler(void) {
     IRQn_Type irq = R_FSP_CurrentIrqGet();
diff --git a/ports/renesas-ra/mphalport.h b/ports/renesas-ra/mphalport.h
index 4f8be705d1..b014f50fa6 100644
--- a/ports/renesas-ra/mphalport.h
+++ b/ports/renesas-ra/mphalport.h
@@ -131,3 +131,5 @@ enum {
 void mp_hal_get_mac(int idx, uint8_t buf[6]);
 
 void mp_hal_set_interrupt_char(int c); // -1 to disable
+
+void mp_hal_get_random(size_t n, uint8_t *buf);
diff --git a/ports/rp2/CMakeLists.txt b/ports/rp2/CMakeLists.txt
index 8b37bce681..2be74151d8 100644
--- a/ports/rp2/CMakeLists.txt
+++ b/ports/rp2/CMakeLists.txt
@@ -194,7 +194,6 @@ set(MICROPY_SOURCE_QSTR
     ${MICROPY_PORT_DIR}/machine_uart.c
     ${MICROPY_PORT_DIR}/machine_wdt.c
     ${MICROPY_PORT_DIR}/modrp2.c
-    ${MICROPY_PORT_DIR}/modos.c
     ${MICROPY_PORT_DIR}/rp2_flash.c
     ${MICROPY_PORT_DIR}/rp2_pio.c
     ${MICROPY_PORT_DIR}/rp2_dma.c
diff --git a/ports/rp2/modos.c b/ports/rp2/modos.c
deleted file mode 100644
index d4ab2f0819..0000000000
--- a/ports/rp2/modos.c
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * This file is part of the MicroPython project, http://micropython.org/
- *
- * The MIT License (MIT)
- *
- * Copyright (c) 2016 Damien P. George
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-#include "py/runtime.h"
-#include "pico/rand.h"
-
-static mp_obj_t mp_os_urandom(mp_obj_t num) {
-    mp_int_t n = mp_obj_get_int(num);
-    vstr_t vstr;
-    vstr_init_len(&vstr, n);
-    for (int i = 0; i < n; i += 8) {
-        uint64_t rand64 = get_rand_64();
-        memcpy(vstr.buf + i, &rand64, MIN(n - i, 8));
-    }
-    return mp_obj_new_bytes_from_vstr(&vstr);
-}
-static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
diff --git a/ports/rp2/mpconfigport.h b/ports/rp2/mpconfigport.h
index fb2d599b91..3c73aa446f 100644
--- a/ports/rp2/mpconfigport.h
+++ b/ports/rp2/mpconfigport.h
@@ -142,7 +142,6 @@
 
 // Extended modules
 #define MICROPY_EPOCH_IS_1970                   (1)
-#define MICROPY_PY_OS_INCLUDEFILE               "ports/rp2/modos.c"
 #ifndef MICROPY_PY_OS_DUPTERM
 #define MICROPY_PY_OS_DUPTERM                   (1)
 #define MICROPY_PY_OS_DUPTERM_NOTIFY            (1)
diff --git a/ports/rp2/mphalport.c b/ports/rp2/mphalport.c
index 4dd510dea4..d46360cb95 100644
--- a/ports/rp2/mphalport.c
+++ b/ports/rp2/mphalport.c
@@ -39,6 +39,7 @@
 #include "hardware/irq.h"
 #include "pico/unique_id.h"
 #include "pico/aon_timer.h"
+#include "pico/rand.h"
 
 #if MICROPY_PY_NETWORK_CYW43
 #include "lib/cyw43-driver/src/cyw43.h"
@@ -277,3 +278,10 @@ int mp_hal_is_pin_reserved(int n) {
     return false;
     #endif
 }
+
+void mp_hal_get_random(size_t n, uint8_t *buf) {
+    for (int i = 0; i < n; i += 8) {
+        uint64_t rand64 = get_rand_64();
+        memcpy(buf + i, &rand64, MIN(n - i, 8));
+    }
+}
diff --git a/ports/rp2/mphalport.h b/ports/rp2/mphalport.h
index 5012b682b9..4afc74e6c9 100644
--- a/ports/rp2/mphalport.h
+++ b/ports/rp2/mphalport.h
@@ -222,5 +222,6 @@ void mp_hal_get_mac(int idx, uint8_t buf[6]);
 void mp_hal_get_mac_ascii(int idx, size_t chr_off, size_t chr_len, char *dest);
 void mp_hal_generate_laa_mac(int idx, uint8_t buf[6]);
 int mp_hal_is_pin_reserved(int n);
+void mp_hal_get_random(size_t n, uint8_t *buf);
 
 #endif // MICROPY_INCLUDED_RP2_MPHALPORT_H
diff --git a/ports/samd/modos.c b/ports/samd/modos.c
index 64d40a46cc..dc43359916 100644
--- a/ports/samd/modos.c
+++ b/ports/samd/modos.c
@@ -72,26 +72,17 @@ uint32_t trng_random_u32(int delay) {
 #define TRNG_RANDOM_U32 trng_random_u32(10)
 #endif
 
-#if MICROPY_PY_OS_URANDOM
-static mp_obj_t mp_os_urandom(mp_obj_t num) {
-    mp_int_t n = mp_obj_get_int(num);
-    vstr_t vstr;
-    vstr_init_len(&vstr, n);
+void mp_hal_get_random(size_t n, uint8_t *buf) {
     uint32_t rngval = 0;
-
     trng_start();
     for (int i = 0; i < n; i++) {
         if ((i % 4) == 0) {
             rngval = TRNG_RANDOM_U32;
         }
-        vstr.buf[i] = rngval & 0xff;
+        buf[i] = rngval & 0xff;
         rngval >>= 8;
     }
-    return mp_obj_new_bytes_from_vstr(&vstr);
 }
-static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
-
-#endif // MICROPY_PY_OS_URANDOM
 
 #if MICROPY_PY_OS_DUPTERM_BUILTIN_STREAM
 bool mp_os_dupterm_is_builtin_stream(mp_const_obj_t stream) {
diff --git a/ports/samd/mphalport.h b/ports/samd/mphalport.h
index 69e2b60640..ed07953016 100644
--- a/ports/samd/mphalport.h
+++ b/ports/samd/mphalport.h
@@ -171,4 +171,6 @@ static inline void mp_hal_pin_od_high(mp_hal_pin_obj_t pin) {
     gpio_set_pin_pull_mode(pin, GPIO_PULL_UP);
 }
 
+void mp_hal_get_random(size_t n, uint8_t *buf);
+
 #endif // MICROPY_INCLUDED_SAMD_MPHALPORT_H
diff --git a/ports/stm32/modos.c b/ports/stm32/modos.c
index cd918fe715..60afece9bc 100644
--- a/ports/stm32/modos.c
+++ b/ports/stm32/modos.c
@@ -26,26 +26,9 @@
 
 #include "py/runtime.h"
 #include "extmod/modmachine.h"
-#include "rng.h"
 #include "usb.h"
 #include "uart.h"
 
-#if MICROPY_PY_OS_URANDOM
-// urandom(n)
-// Return a bytes object with n random bytes, generated by the hardware
-// random number generator.
-static mp_obj_t mp_os_urandom(mp_obj_t num) {
-    mp_int_t n = mp_obj_get_int(num);
-    vstr_t vstr;
-    vstr_init_len(&vstr, n);
-    for (int i = 0; i < n; i++) {
-        vstr.buf[i] = rng_get();
-    }
-    return mp_obj_new_bytes_from_vstr(&vstr);
-}
-static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
-#endif
-
 bool mp_os_dupterm_is_builtin_stream(mp_const_obj_t stream) {
     const mp_obj_type_t *type = mp_obj_get_type(stream);
     return false
diff --git a/ports/stm32/mphalport.c b/ports/stm32/mphalport.c
index e862b46edc..0481a962f7 100644
--- a/ports/stm32/mphalport.c
+++ b/ports/stm32/mphalport.c
@@ -7,6 +7,7 @@
 #include "extmod/misc.h"
 #include "usb.h"
 #include "uart.h"
+#include "rng.h"
 
 #if MICROPY_HW_TINYUSB_STACK
 #include "shared/tinyusb/mp_usbd_cdc.h"
@@ -221,4 +222,15 @@ void mp_hal_get_mac_ascii(int idx, size_t chr_off, size_t chr_len, char *dest) {
     }
 }
 
+void mp_hal_get_random(size_t n, uint8_t *buf) {
+    uint32_t val = 0;
+    for (int i = 0; i < n; i++) {
+        if ((i & 3) == 0) {
+            val = rng_get();
+        }
+        buf[i] = val;
+        val >>= 8;
+    }
+}
+
 MP_REGISTER_ROOT_POINTER(struct _machine_uart_obj_t *pyb_stdio_uart);
diff --git a/ports/stm32/mphalport.h b/ports/stm32/mphalport.h
index a742a92fc2..fe144c6eed 100644
--- a/ports/stm32/mphalport.h
+++ b/ports/stm32/mphalport.h
@@ -173,6 +173,7 @@ enum {
 void mp_hal_generate_laa_mac(int idx, uint8_t buf[6]);
 void mp_hal_get_mac(int idx, uint8_t buf[6]);
 void mp_hal_get_mac_ascii(int idx, size_t chr_off, size_t chr_len, char *dest);
+void mp_hal_get_random(size_t n, uint8_t *buf);
 
 static inline void mp_hal_wake_main_task_from_isr(void) {
     // Defined for tinyusb support, nothing needs to be done here.
diff --git a/ports/unix/modos.c b/ports/unix/modos.c
index 92211d689c..59f31e2782 100644
--- a/ports/unix/modos.c
+++ b/ports/unix/modos.c
@@ -92,15 +92,6 @@ static mp_obj_t mp_os_system(mp_obj_t cmd_in) {
 }
 static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_system_obj, mp_os_system);
 
-static mp_obj_t mp_os_urandom(mp_obj_t num) {
-    mp_int_t n = mp_obj_get_int(num);
-    vstr_t vstr;
-    vstr_init_len(&vstr, n);
-    mp_hal_get_random(n, vstr.buf);
-    return mp_obj_new_bytes_from_vstr(&vstr);
-}
-static MP_DEFINE_CONST_FUN_OBJ_1(mp_os_urandom_obj, mp_os_urandom);
-
 static mp_obj_t mp_os_errno(size_t n_args, const mp_obj_t *args) {
     if (n_args == 0) {
         return MP_OBJ_NEW_SMALL_INT(errno);
diff --git a/ports/unix/mpconfigport.h b/ports/unix/mpconfigport.h
index e290935bca..44e8402093 100644
--- a/ports/unix/mpconfigport.h
+++ b/ports/unix/mpconfigport.h
@@ -180,10 +180,10 @@ void mp_unix_free_exec(void *ptr, size_t size);
 // If enabled, configure how to seed random on init.
 #ifdef MICROPY_PY_RANDOM_SEED_INIT_FUNC
 #include <stddef.h>
-void mp_hal_get_random(size_t n, void *buf);
+void mp_hal_get_random(size_t n, uint8_t *buf);
 static inline unsigned long mp_random_seed_init(void) {
     unsigned long r;
-    mp_hal_get_random(sizeof(r), &r);
+    mp_hal_get_random(sizeof(r), (uint8_t *)&r);
     return r;
 }
 #endif
diff --git a/ports/unix/mphalport.h b/ports/unix/mphalport.h
index 57184c4c2e..5d8004e5e4 100644
--- a/ports/unix/mphalport.h
+++ b/ports/unix/mphalport.h
@@ -112,7 +112,7 @@ static inline void mp_hal_delay_us(mp_uint_t us) {
     { if (err_flag == -1) \
       { mp_raise_OSError(error_val); } }
 
-void mp_hal_get_random(size_t n, void *buf);
+void mp_hal_get_random(size_t n, uint8_t *buf);
 
 #if MICROPY_PY_BLUETOOTH
 enum {
diff --git a/ports/unix/unix_mphal.c b/ports/unix/unix_mphal.c
index 39311c9872..b0861aaa77 100644
--- a/ports/unix/unix_mphal.c
+++ b/ports/unix/unix_mphal.c
@@ -253,7 +253,7 @@ void mp_hal_delay_ms(mp_uint_t ms) {
 }
 #endif
 
-void mp_hal_get_random(size_t n, void *buf) {
+void mp_hal_get_random(size_t n, uint8_t *buf) {
     #ifdef _HAVE_GETRANDOM
     RAISE_ERRNO(getrandom(buf, n, 0), errno);
     #else
diff --git a/ports/windows/windows_mphal.c b/ports/windows/windows_mphal.c
index 5a65b2fd2a..50b7a40bf4 100644
--- a/ports/windows/windows_mphal.c
+++ b/ports/windows/windows_mphal.c
@@ -289,7 +289,7 @@ void mp_hal_delay_ms(mp_uint_t ms) {
     #endif
 }
 
-void mp_hal_get_random(size_t n, void *buf) {
+void mp_hal_get_random(size_t n, uint8_t *buf) {
     NTSTATUS result = BCryptGenRandom(NULL, (unsigned char *)buf, n, BCRYPT_USE_SYSTEM_PREFERRED_RNG);
     if (!BCRYPT_SUCCESS(result)) {
         mp_raise_OSError(errno);