diff --git a/.gitmodules b/.gitmodules
index 7c382da67..eb4b7b4fd 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -13,3 +13,6 @@
 [submodule "lib/btstack"]
 	path = lib/btstack
 	url = https://github.com/bluekitchen/btstack.git
+[submodule "lib/uzlib"]
+	path = lib/uzlib
+	url = git@github.com:pfalcon/uzlib.git
diff --git a/lib/cyw43-driver b/lib/cyw43-driver
index 9bfca6117..24362d6cd 160000
--- a/lib/cyw43-driver
+++ b/lib/cyw43-driver
@@ -1 +1 @@
-Subproject commit 9bfca61173a94432839cd39210f1d1afdf602c42
+Subproject commit 24362d6cd2a1e6d34ace9d369059f36f525e42a6
diff --git a/lib/uzlib b/lib/uzlib
new file mode 160000
index 000000000..6d60d651a
--- /dev/null
+++ b/lib/uzlib
@@ -0,0 +1 @@
+Subproject commit 6d60d651a4499a64f2e5b21b4cc08d98cb84b5c1
diff --git a/src/rp2_common/CMakeLists.txt b/src/rp2_common/CMakeLists.txt
index eff827b6a..30d084974 100644
--- a/src/rp2_common/CMakeLists.txt
+++ b/src/rp2_common/CMakeLists.txt
@@ -67,6 +67,7 @@ if (NOT PICO_BARE_METAL)
     pico_add_subdirectory(pico_lwip)
     pico_add_subdirectory(pico_cyw43_arch)
     pico_add_subdirectory(pico_mbedtls)
+    pico_add_subdirectory(pico_uzlib)
 
     pico_add_subdirectory(pico_stdlib)
 
@@ -84,4 +85,4 @@ set(CMAKE_EXECUTABLE_SUFFIX "${CMAKE_EXECUTABLE_SUFFIX}" PARENT_SCOPE)
 pico_add_doxygen(${CMAKE_CURRENT_LIST_DIR})
 pico_add_doxygen_exclude(${CMAKE_CURRENT_LIST_DIR}/cmsis)
 
-pico_promote_common_scope_vars()
\ No newline at end of file
+pico_promote_common_scope_vars()
diff --git a/src/rp2_common/pico_cyw43_driver/CMakeLists.txt b/src/rp2_common/pico_cyw43_driver/CMakeLists.txt
index 4cdf95b33..ebee1f87b 100644
--- a/src/rp2_common/pico_cyw43_driver/CMakeLists.txt
+++ b/src/rp2_common/pico_cyw43_driver/CMakeLists.txt
@@ -15,6 +15,10 @@ elseif (NOT EXISTS ${PICO_CYW43_DRIVER_PATH}/${CYW43_DRIVER_TEST_FILE})
     message(WARNING "PICO_CYW43_DRIVER_PATH specified but content not present.")
 endif()
 
+if (NOT DEFINED PICO_CYW43_DRIVER_USES_UZLIB)
+    set(PICO_CYW43_DRIVER_USES_UZLIB 1)
+endif()
+
 if (EXISTS ${PICO_CYW43_DRIVER_PATH}/${CYW43_DRIVER_TEST_FILE})
     message("cyw43-driver available at ${PICO_CYW43_DRIVER_PATH}")
 
@@ -29,6 +33,7 @@ if (EXISTS ${PICO_CYW43_DRIVER_PATH}/${CYW43_DRIVER_TEST_FILE})
             ${PICO_CYW43_DRIVER_PATH}/src/cyw43_stats.c
             ${PICO_CYW43_DRIVER_PATH}/src/cyw43_lwip.c
             ${PICO_CYW43_DRIVER_PATH}/src/cyw43_ctrl.c
+            ${PICO_CYW43_DRIVER_PATH}/src/cyw43_gz_read.c
             )
     target_include_directories(cyw43_driver_headers INTERFACE
             ${PICO_CYW43_DRIVER_PATH}/src
@@ -55,7 +60,12 @@ if (EXISTS ${PICO_CYW43_DRIVER_PATH}/${CYW43_DRIVER_TEST_FILE})
             hardware_dma
             hardware_exception
             )
-
+    # MP has its own uzlib driver that's used for firmware decompression
+    if (PICO_CYW43_DRIVER_USES_UZLIB)
+        pico_mirrored_target_link_libraries(cyw43_driver_picow INTERFACE
+                pico_uzlib
+                )
+    endif()
     # Note: This is used by MP, so check for issues when making changes
     # e.g. Don't add new depenedences
     pico_add_library(pico_btstack_hci_transport_cyw43 NOFLAG)
diff --git a/src/rp2_common/pico_cyw43_driver/cybt_shared_bus/cybt_shared_bus.c b/src/rp2_common/pico_cyw43_driver/cybt_shared_bus/cybt_shared_bus.c
index b464b3f78..a2b763082 100644
--- a/src/rp2_common/pico_cyw43_driver/cybt_shared_bus/cybt_shared_bus.c
+++ b/src/rp2_common/pico_cyw43_driver/cybt_shared_bus/cybt_shared_bus.c
@@ -14,8 +14,6 @@
 #include "cyw43_config.h"
 #include "cybt_shared_bus_driver.h"
 
-#include "cyw43_btfw_43439.h"
-
 #if CYW43_USE_HEX_BTFW
 extern const char    brcm_patch_version[];
 extern const uint8_t brcm_patchram_buf[];
@@ -124,8 +122,8 @@ int cyw43_btbus_init(cyw43_ll_t *self) {
     }
 
     cybt_debug("cybt_fw_download\n");
-    const uint8_t *fw_data_buf;
-    uint32_t fw_data_len;
+    const uint8_t *fw_data_buf = NULL;
+    uint32_t fw_data_len = 0;
 #if CYW43_USE_HEX_BTFW
     cybt_printf("CYW43_USE_HEX_BTFW is true\n");
 #ifndef NDEBUG
@@ -133,16 +131,11 @@ int cyw43_btbus_init(cyw43_ll_t *self) {
 #endif
     fw_data_len = brcm_patch_ram_length;
     fw_data_buf = brcm_patchram_buf;
-#else
-    fw_data_len = cyw43_btfw_43439_len;
-    fw_data_buf = cyw43_btfw_43439;
 #endif
     ret = cybt_fw_download(fw_data_buf,
                            fw_data_len,
                            p_write_buf,
-                           p_hex_buf
-    );
-
+                           p_hex_buf);
     cybt_debug("cybt_fw_download_finish\n");
     cybt_fw_download_finish(p_write_buf, p_hex_buf);
 
diff --git a/src/rp2_common/pico_cyw43_driver/cybt_shared_bus/cybt_shared_bus_driver.c b/src/rp2_common/pico_cyw43_driver/cybt_shared_bus/cybt_shared_bus_driver.c
index 8de0f6ad3..924449455 100644
--- a/src/rp2_common/pico_cyw43_driver/cybt_shared_bus/cybt_shared_bus_driver.c
+++ b/src/rp2_common/pico_cyw43_driver/cybt_shared_bus/cybt_shared_bus_driver.c
@@ -11,6 +11,7 @@
 
 #include "cyw43_ll.h"
 #include "cybt_shared_bus_driver.h"
+#include "cyw43_firmware_defs.h"
 
 // Bluetooth register corruption occurs if both wifi and bluetooth are fully utilised.
 #define CYBT_CORRUPTION_TEST 1
@@ -80,7 +81,7 @@ typedef struct
     uint32_t bt2host_out_addr;
 } cybt_fw_membuf_info_t;
 
-cybt_fw_membuf_info_t buf_info;
+static cybt_fw_membuf_info_t buf_info;
 
 #define BTFW_ADDR_MODE_UNKNOWN      (0)
 #define BTFW_ADDR_MODE_EXTENDED     (1)
@@ -111,7 +112,6 @@ cybt_fw_membuf_info_t buf_info;
 
 typedef struct cybt_fw_cb
 {
-    const uint8_t *p_fw_mem_start;
     uint32_t fw_len;
     const uint8_t *p_next_line_start;
 } cybt_fw_cb_t;
@@ -131,6 +131,7 @@ typedef struct hex_file_data
 #endif
 
 static cyw43_ll_t *cyw43_ll = NULL;
+static void *streaming_context;
 
 static cybt_result_t cybt_reg_write(uint32_t reg_addr, uint32_t value);
 static cybt_result_t cybt_reg_read(uint32_t reg_addr, uint32_t *p_value);
@@ -261,21 +262,37 @@ static uint32_t cybt_fw_get_data(cybt_fw_cb_t *p_btfw_cb,
 }
 #else
 
+static void cybt_fw_get_bytes(uint8_t *dst, const uint8_t **addr, uint8_t count) {
+#if CYW43_USE_HEX_BTFW
+    memcpy(dst, *addr, count);
+#else
+    const uint8_t *data = cyw43_get_firmware_funcs()->stream_fw(streaming_context, count, dst);
+    if (data != dst) {
+        memcpy(dst, data, count);
+    }
+#endif
+    *addr += count;
+}
+
 static uint32_t cybt_fw_get_data(cybt_fw_cb_t *p_btfw_cb, hex_file_data_t *hfd) {
     uint32_t abs_base_addr32 = 0;
     while (true) {
         // 4 byte header
-        uint8_t num_bytes = *(p_btfw_cb->p_next_line_start)++;
-        uint16_t addr = *(p_btfw_cb->p_next_line_start)++ << 8;
-        addr |= *(p_btfw_cb->p_next_line_start)++;
-        uint8_t type = *(p_btfw_cb->p_next_line_start)++;
+        uint8_t num_bytes;
+        cybt_fw_get_bytes(&num_bytes, &p_btfw_cb->p_next_line_start, 1);
+
+        uint16_t addr;
+        cybt_fw_get_bytes((uint8_t*)&addr, &p_btfw_cb->p_next_line_start, 2);
+        addr = (((addr >> 8) & 0xff) | ((addr & 0xff) << 8));
+
+        uint8_t type;
+        cybt_fw_get_bytes(&type, &p_btfw_cb->p_next_line_start, 1);
 
         // No data?
         if (num_bytes == 0) break;
 
         // Copy the data
-        memcpy(hfd->p_ds, p_btfw_cb->p_next_line_start, num_bytes);
-        p_btfw_cb->p_next_line_start += num_bytes;
+        cybt_fw_get_bytes(hfd->p_ds, &p_btfw_cb->p_next_line_start, num_bytes);
 
         // Adjust address based on type
         if (type == BTFW_HEX_LINE_TYPE_EXTENDED_ADDRESS) {
@@ -318,19 +335,29 @@ cybt_result_t cybt_fw_download(const uint8_t *p_bt_firmware,
         return CYBT_ERR_BADARG;
     }
 
-    if (NULL == p_bt_firmware || 0 == bt_firmware_len || NULL == p_write_buf || NULL == p_hex_buf) {
+    if (NULL == p_write_buf || NULL == p_hex_buf) {
         return CYBT_ERR_BADARG;
     }
-
+#if CYW43_USE_HEX_BTFW
+    if (NULL == p_bt_firmware || 0 == bt_firmware_len) {
+        return CYBT_ERR_BADARG;
+    }
+#else
+    if (cyw43_get_firmware_funcs()->start_fw_stream(cyw43_get_firmware_funcs()->firmware_details(), CYW43_FIRMWARE_BLUETOOTH, &streaming_context) != 0) {
+        assert(false);
+        return CYW43_EIO;
+    }
     // BT firmware starts with length of version string including a null terminator
-#if !CYW43_USE_HEX_BTFW
-    uint8_t version_len = *p_bt_firmware;
-    assert(*(p_bt_firmware + version_len) == 0);
+    uint8_t version_len;
+    cybt_fw_get_bytes(&version_len, &p_bt_firmware, 1);
+    cybt_fw_get_bytes(p_hex_buf, &p_bt_firmware, version_len);
+    assert(*(p_hex_buf + version_len - 1) == 0);
 #ifndef NDEBUG
-    cybt_printf("BT FW download, version = %s\n", p_bt_firmware + 1);
+    cybt_printf("BT FW download, version = %s\n", p_hex_buf);
 #endif
-    p_bt_firmware += version_len + 1; // skip over version
-    p_bt_firmware += 1; // skip over record count
+    uint8_t record_count;
+    cybt_fw_get_bytes(&record_count, &p_bt_firmware, 1);
+    (void)record_count;
 #endif
 
     p_mem_ptr = p_write_buf;
@@ -340,7 +367,6 @@ cybt_result_t cybt_fw_download(const uint8_t *p_bt_firmware,
 
     hfd.p_ds = p_hex_buf;
 
-    btfw_cb.p_fw_mem_start = p_bt_firmware;
     btfw_cb.fw_len = bt_firmware_len;
     btfw_cb.p_next_line_start = p_bt_firmware;
 
@@ -395,7 +421,9 @@ cybt_result_t cybt_fw_download(const uint8_t *p_bt_firmware,
                            write_data_len - first_write_len);
         }
     }
-
+#if !CYW43_USE_HEX_BTFW
+    cyw43_get_firmware_funcs()->end_fw_stream(streaming_context, CYW43_FIRMWARE_BLUETOOTH);
+#endif
     return CYBT_SUCCESS;
 }
 
diff --git a/src/rp2_common/pico_cyw43_driver/cyw43_bus_pio_spi.c b/src/rp2_common/pico_cyw43_driver/cyw43_bus_pio_spi.c
index 169933010..7fbc63805 100644
--- a/src/rp2_common/pico_cyw43_driver/cyw43_bus_pio_spi.c
+++ b/src/rp2_common/pico_cyw43_driver/cyw43_bus_pio_spi.c
@@ -534,9 +534,14 @@ int cyw43_write_bytes(cyw43_int_t *self, uint32_t fn, uint32_t addr, size_t len,
         int res = cyw43_spi_transfer(self, (uint8_t *)&self->spi_header[1], aligned_len + 4, NULL, 0);
         logic_debug_set(pin_WIFI_TX, 0);
         return res;
+    } else if (src > self->spid_buf + sizeof(uint32_t) && src < (self->spid_buf + sizeof(self->spid_buf))) {
+        assert(src + len <= (self->spid_buf + sizeof(self->spid_buf))); // don't go over the end of the buffer
+        uint32_t *spi_header = (void*)(self->spid_buf + (src - self->spid_buf) - sizeof(uint32_t));
+        *spi_header = make_cmd(true, true, fn, addr, len);
+        return cyw43_spi_transfer(self, (uint8_t *)spi_header, aligned_len + 4, NULL, 0);
     } else {
         // todo: would be nice to get rid of this. Only used for firmware download?
-        assert(src < self->spid_buf || src >= (self->spid_buf + sizeof(self->spid_buf)));
+        assert(src < self->spid_buf || src >= (self->spid_buf + sizeof(self->spid_buf))); // check we're not using self->spid_buf
         self->spi_header[1] = make_cmd(true, true, fn, addr, len);
         memcpy(self->spid_buf, src, len);
         return cyw43_spi_transfer(self, (uint8_t *)&self->spi_header[1], aligned_len + 4, NULL, 0);
diff --git a/src/rp2_common/pico_cyw43_driver/include/cyw43_configport.h b/src/rp2_common/pico_cyw43_driver/include/cyw43_configport.h
index f012d2458..be62930c2 100644
--- a/src/rp2_common/pico_cyw43_driver/include/cyw43_configport.h
+++ b/src/rp2_common/pico_cyw43_driver/include/cyw43_configport.h
@@ -12,6 +12,7 @@
 #include "pico.h"
 #include "hardware/gpio.h"
 #include "pico/time.h"
+#include "hardware/flash.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -62,18 +63,39 @@ extern "C" {
 #define CYW43_SPI_PIO 1
 #endif
 
+// Compress firmware by default
+#ifndef CYW43_ENABLE_FIRMWARE_COMPRESSION
+#define CYW43_ENABLE_FIRMWARE_COMPRESSION 1
+#endif
+
 #ifndef CYW43_CHIPSET_FIRMWARE_INCLUDE_FILE
 #if CYW43_ENABLE_BLUETOOTH
+#if CYW43_ENABLE_FIRMWARE_COMPRESSION
+#define CYW43_CHIPSET_FIRMWARE_INCLUDE_FILE "wb43439A0_7_95_49_00_combined.gz.h"
+#else
 #define CYW43_CHIPSET_FIRMWARE_INCLUDE_FILE "wb43439A0_7_95_49_00_combined.h"
+#endif
+#else
+#if CYW43_ENABLE_FIRMWARE_COMPRESSION
+#define CYW43_CHIPSET_FIRMWARE_INCLUDE_FILE "w43439A0_7_95_49_00_combined.gz.h"
 #else
 #define CYW43_CHIPSET_FIRMWARE_INCLUDE_FILE "w43439A0_7_95_49_00_combined.h"
 #endif
 #endif
+#endif
 
 #ifndef CYW43_WIFI_NVRAM_INCLUDE_FILE
 #define CYW43_WIFI_NVRAM_INCLUDE_FILE "wifi_nvram_43439.h"
 #endif
 
+#ifndef CYW43_BT_FIRMWARE_INCLUDE_FILE
+#if CYW43_ENABLE_FIRMWARE_COMPRESSION
+#define CYW43_BT_FIRMWARE_INCLUDE_FILE "cyw43_btfw_43439.gz.h"
+#else
+#define CYW43_BT_FIRMWARE_INCLUDE_FILE "cyw43_btfw_43439.h"
+#endif
+#endif
+
 // Note, these are negated, because cyw43_driver negates them before returning!
 #define CYW43_EPERM            (-PICO_ERROR_NOT_PERMITTED) // Operation not permitted
 #define CYW43_EIO              (-PICO_ERROR_IO) // I/O error
@@ -170,4 +192,4 @@ void cyw43_post_poll_hook(void);
 #endif
 
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/rp2_common/pico_uzlib/CMakeLists.txt b/src/rp2_common/pico_uzlib/CMakeLists.txt
new file mode 100644
index 000000000..3eb1399be
--- /dev/null
+++ b/src/rp2_common/pico_uzlib/CMakeLists.txt
@@ -0,0 +1,36 @@
+set(UZLIB_TEST_PATH "tinflate.c")
+if (NOT PICO_UZLIB_SRC_PATH)
+    set(PICO_UZLIB_SRC_PATH ${PROJECT_SOURCE_DIR}/lib/uzlib/src)
+endif()
+if (NOT EXISTS ${PICO_UZLIB_SRC_PATH}/${UZLIB_TEST_PATH})
+    message(WARNING "uzlib content not present.")
+endif()
+
+if (EXISTS ${PICO_UZLIB_SRC_PATH}/${UZLIB_TEST_PATH})
+    message("uzlib source available at ${PICO_UZLIB_SRC_PATH}")
+
+    pico_register_common_scope_var(PICO_UZLIB_PATH)
+
+    pico_add_library(pico_uzlib)
+    target_sources(pico_uzlib INTERFACE
+        ${PICO_UZLIB_SRC_PATH}/tinflate.c
+        ${PICO_UZLIB_SRC_PATH}/tinfgzip.c
+        ${PICO_UZLIB_SRC_PATH}/tinfzlib.c
+        ${PICO_UZLIB_SRC_PATH}/adler32.c
+        ${PICO_UZLIB_SRC_PATH}/crc32.c
+    )
+    target_include_directories(pico_uzlib_headers INTERFACE
+        ${PICO_UZLIB_SRC_PATH}
+    )
+
+    pico_promote_common_scope_vars()
+
+    function(suppress_uzlib_warnings)
+        set_source_files_properties(
+            ${PICO_UZLIB_SRC_PATH}/tinflate.c
+            PROPERTIES
+            COMPILE_OPTIONS "-Wno-sign-compare"
+            )
+    endfunction()
+
+endif()
\ No newline at end of file
diff --git a/test/kitchen_sink/CMakeLists.txt b/test/kitchen_sink/CMakeLists.txt
index 807ec47a7..c5ace53c8 100644
--- a/test/kitchen_sink/CMakeLists.txt
+++ b/test/kitchen_sink/CMakeLists.txt
@@ -42,6 +42,7 @@ target_link_libraries(kitchen_sink_libs INTERFACE
     pico_time
     pico_unique_id
     pico_util
+    pico_uzlib
 )
 
 add_library(kitchen_sink_options INTERFACE)
@@ -177,3 +178,7 @@ endif()
 if (TARGET pico_btstack_base AND COMMAND suppress_btstack_warnings)
     suppress_btstack_warnings()
 endif()
+
+if (TARGET pico_uzlib AND COMMAND suppress_uzlib_warnings)
+    suppress_uzlib_warnings()
+endif()