diff --git a/micropython/boardloader/main.c b/micropython/boardloader/main.c
index 85bd5ae4b..a98562e63 100644
--- a/micropython/boardloader/main.c
+++ b/micropython/boardloader/main.c
@@ -51,7 +51,7 @@ bool check_sdcard(void)
     }
 }
 
-static void progress_callback(void) {
+static void progress_callback(uint16_t val) {
     display_printf(".");
 }
 
diff --git a/micropython/bootloader/main.c b/micropython/bootloader/main.c
index a16ac5432..39d6e792c 100644
--- a/micropython/bootloader/main.c
+++ b/micropython/bootloader/main.c
@@ -35,7 +35,8 @@ void display_vendor(const uint8_t *vimg, const char *vstr, uint32_t vstr_len, ui
     }
     uint32_t datalen = *(uint32_t *)(vimg + 8);
     display_image(60, 32, w, h, vimg + 12, datalen);
-    display_text_center(120, 192, vstr, vstr_len, FONT_BOLD, COLOR_WHITE, COLOR_BLACK);
+// FIXME: uncomment next line
+//    display_text_center(120, 192, vstr, vstr_len, FONT_BOLD, COLOR_WHITE, COLOR_BLACK);
     char ver_str[32];
     mini_snprintf(ver_str, sizeof(ver_str), "%d.%d.%d.%d",
         (int)(fw_version & 0xFF),
@@ -43,7 +44,8 @@ void display_vendor(const uint8_t *vimg, const char *vstr, uint32_t vstr_len, ui
         (int)((fw_version >> 16) & 0xFF),
         (int)((fw_version >> 24) & 0xFF)
     );
-    display_text_center(120, 215, ver_str, -1, FONT_BOLD, COLOR_GRAY64, COLOR_BLACK);
+// FIXME: uncomment next line
+//    display_text_center(120, 215, ver_str, -1, FONT_BOLD, COLOR_GRAY64, COLOR_BLACK);
     display_refresh();
 }
 
@@ -155,6 +157,9 @@ void mainloop(void)
         __fatal_error("usb_init_all", __FILE__, __LINE__, __FUNCTION__);
     }
 
+    display_clear();
+    display_loader(0, 0, 0xFFFF, 0, 0, 0, 0);
+
     uint8_t buf[USB_PACKET_SIZE];
 
     for (;;) {
@@ -171,23 +176,18 @@ void mainloop(void)
         }
         switch (msg_id) {
             case 0: // Initialize
-                display_printf("received Initialize\n");
                 process_msg_Initialize(USB_IFACE_NUM, msg_size, buf);
                 break;
             case 1: // Ping
-                display_printf("received Ping\n");
                 process_msg_Ping(USB_IFACE_NUM, msg_size, buf);
                 break;
             case 6: // FirmwareErase
-                display_printf("received FirmwareErase\n");
                 process_msg_FirmwareErase(USB_IFACE_NUM, msg_size, buf);
                 break;
             case 7: // FirmwareUpload
-                display_printf("received FirmwareUpload\n");
                 process_msg_FirmwareUpload(USB_IFACE_NUM, msg_size, buf);
                 break;
             default:
-                display_printf("received unknown message\n");
                 process_msg_unknown(USB_IFACE_NUM, msg_size, buf);
                 break;
         }
diff --git a/micropython/bootloader/messages.c b/micropython/bootloader/messages.c
index 071d527ee..a95245775 100644
--- a/micropython/bootloader/messages.c
+++ b/micropython/bootloader/messages.c
@@ -7,6 +7,7 @@
 #include "messages.pb.h"
 
 #include "common.h"
+#include "display.h"
 #include "flash.h"
 #include "usb.h"
 #include "version.h"
@@ -15,12 +16,12 @@
 
 bool msg_parse_header(const uint8_t *buf, uint16_t *msg_id, uint32_t *msg_size)
 {
-        if (buf[0] != '?' || buf[1] != '#' || buf[2] != '#') {
-            return false;
-        }
-        *msg_id = (buf[3] << 8) + buf[4];
-        *msg_size = (buf[5] << 24) + (buf[6] << 16) + (buf[7] << 8) + buf[8];
-        return true;
+    if (buf[0] != '?' || buf[1] != '#' || buf[2] != '#') {
+        return false;
+    }
+    *msg_id = (buf[3] << 8) + buf[4];
+    *msg_size = (buf[5] << 24) + (buf[6] << 16) + (buf[7] << 8) + buf[8];
+    return true;
 }
 
 typedef struct {
@@ -220,23 +221,28 @@ void process_msg_Ping(uint8_t iface_num, uint32_t msg_size, uint8_t *buf)
     MSG_SEND(Success);
 }
 
-static uint32_t firmware_size, firmware_flashed, chunk_requested;
+static uint32_t firmware_remaining, firmware_flashed, chunk_requested;
+
+static void progress_erase(uint16_t val)
+{
+    display_loader(val, 0, 0xFFFF, 0, 0, 0, 0);
+}
 
 void process_msg_FirmwareErase(uint8_t iface_num, uint32_t msg_size, uint8_t *buf)
 {
-    firmware_size = 0;
+    firmware_remaining = 0;
     firmware_flashed = 0;
     chunk_requested = 0;
 
     MSG_RECV_INIT(FirmwareErase);
     MSG_RECV(FirmwareErase);
 
-    firmware_size = msg_recv.has_length ? msg_recv.length : 0;
-    if (firmware_size > 0 && firmware_size % 4 == 0) {
+    firmware_remaining = msg_recv.has_length ? msg_recv.length : 0;
+    if (firmware_remaining > 0 && firmware_remaining % 4 == 0) {
         // erase flash
-        flash_erase_sectors(FLASH_SECTOR_FIRMWARE_START, FLASH_SECTOR_FIRMWARE_END, NULL);
+        flash_erase_sectors(FLASH_SECTOR_FIRMWARE_START, FLASH_SECTOR_FIRMWARE_END, progress_erase);
         // request new firmware
-        chunk_requested = (firmware_size > FIRMWARE_CHUNK_SIZE) ? FIRMWARE_CHUNK_SIZE : firmware_size;
+        chunk_requested = (firmware_remaining > FIRMWARE_CHUNK_SIZE) ? FIRMWARE_CHUNK_SIZE : firmware_remaining;
         MSG_SEND_INIT(FirmwareRequest);
         MSG_SEND_ASSIGN_VALUE(offset, 0);
         MSG_SEND_ASSIGN_VALUE(length, chunk_requested);
@@ -253,11 +259,13 @@ static uint32_t chunk_size = 0;
 
 static bool _read_payload(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
-#define BUFSIZE 1024
+#define BUFSIZE 4096
     uint32_t buf[BUFSIZE / sizeof(uint32_t)];
     uint32_t chunk_written = 0;
     chunk_size = stream->bytes_left;
     while (stream->bytes_left) {
+        // print loader
+        display_loader(1000 * (firmware_flashed + chunk_written) / (firmware_flashed + firmware_remaining), 0, 0xFFFF, 0, 0, 0, 0);
         memset(buf, 0xFF, sizeof(buf));
         // read data
         if (!pb_read(stream, (pb_byte_t *)buf, (stream->bytes_left > BUFSIZE) ? BUFSIZE : stream->bytes_left)) {
@@ -289,16 +297,17 @@ void process_msg_FirmwareUpload(uint8_t iface_num, uint32_t msg_size, uint8_t *b
         MSG_SEND(Failure);
     }
 
-    firmware_size -= chunk_requested;
+    firmware_remaining -= chunk_requested;
     firmware_flashed += chunk_requested;
 
-    if (firmware_size > 0) {
-        chunk_requested = (firmware_size > FIRMWARE_CHUNK_SIZE) ? FIRMWARE_CHUNK_SIZE : firmware_size;
+    if (firmware_remaining > 0) {
+        chunk_requested = (firmware_remaining > FIRMWARE_CHUNK_SIZE) ? FIRMWARE_CHUNK_SIZE : firmware_remaining;
         MSG_SEND_INIT(FirmwareRequest);
         MSG_SEND_ASSIGN_VALUE(offset, firmware_flashed);
         MSG_SEND_ASSIGN_VALUE(length, chunk_requested);
         MSG_SEND(FirmwareRequest);
     } else {
+        display_clear();
         MSG_SEND_INIT(Success);
         MSG_SEND(Success);
     }
diff --git a/micropython/trezorhal/flash.c b/micropython/trezorhal/flash.c
index 234d59681..2288d9eff 100644
--- a/micropython/trezorhal/flash.c
+++ b/micropython/trezorhal/flash.c
@@ -39,7 +39,7 @@ void flash_set_option_bytes(void)
     }
 }
 
-int flash_erase_sectors(int start, int end, void (*progress)(void))
+int flash_erase_sectors(int start, int end, void (*progress)(uint16_t val))
 {
     HAL_FLASH_Unlock();
     FLASH_EraseInitTypeDef EraseInitStruct;
@@ -56,7 +56,7 @@ int flash_erase_sectors(int start, int end, void (*progress)(void))
             return 0;
         }
         if (progress) {
-            progress();
+            progress(1000 * (i - start + 1) / (end - start + 1));
         }
     }
     HAL_FLASH_Lock();
diff --git a/micropython/trezorhal/flash.h b/micropython/trezorhal/flash.h
index 670b7f11e..00d52863b 100644
--- a/micropython/trezorhal/flash.h
+++ b/micropython/trezorhal/flash.h
@@ -1,6 +1,8 @@
 #ifndef __TREZORHAL_FLASH_H__
 #define __TREZORHAL_FLASH_H__
 
+#include <stdint.h>
+
 int flash_init(void);
 
 void flash_set_option_bytes(void);
@@ -17,6 +19,6 @@ void flash_set_option_bytes(void);
 #define FLASH_SECTOR_FIRMWARE_START    5
 #define FLASH_SECTOR_FIRMWARE_END      11
 
-int flash_erase_sectors(int start, int end, void (*progress)(void));
+int flash_erase_sectors(int start, int end, void (*progress)(uint16_t val));
 
 #endif