From a6756195de42e15d3be2b371a2ba49f0d179bceb Mon Sep 17 00:00:00 2001
From: hasslesstech <hasslesstech@tutanota.com>
Date: Sun, 28 Dec 2025 21:50:17 +0200
Subject: [PATCH 1/9] Issue #26: Change linker script to prohibit the usage of
 sector 1 in flash memory

---
 .cproject                     |   2 +-
 STM32F407VGTX_FLASH_custom.ld | 209 ++++++++++++++++++++++++++++++++++
 2 files changed, 210 insertions(+), 1 deletion(-)
 create mode 100644 STM32F407VGTX_FLASH_custom.ld

diff --git a/.cproject b/.cproject
index e498386..eed3eb1 100644
--- a/.cproject
+++ b/.cproject
@@ -80,7 +80,7 @@
 								<option id="com.st.stm32cube.ide.mcu.gnu.managedbuild.tool.cpp.compiler.option.optimization.level.2032300559" name="Optimization level" superClass="com.st.stm32cube.ide.mcu.gnu.managedbuild.tool.cpp.compiler.option.optimization.level" useByScannerDiscovery="false"/>
 							</tool>
 							<tool id="com.st.stm32cube.ide.mcu.gnu.managedbuild.tool.c.linker.1428656477" name="MCU GCC Linker" superClass="com.st.stm32cube.ide.mcu.gnu.managedbuild.tool.c.linker">
-								<option id="com.st.stm32cube.ide.mcu.gnu.managedbuild.tool.c.linker.option.script.227955233" name="Linker Script (-T)" superClass="com.st.stm32cube.ide.mcu.gnu.managedbuild.tool.c.linker.option.script" value="${workspace_loc:/${ProjName}/STM32F407VGTX_FLASH.ld}" valueType="string"/>
+								<option id="com.st.stm32cube.ide.mcu.gnu.managedbuild.tool.c.linker.option.script.227955233" name="Linker Script (-T)" superClass="com.st.stm32cube.ide.mcu.gnu.managedbuild.tool.c.linker.option.script" value="${workspace_loc:/${ProjName}/STM32F407VGTX_FLASH_custom.ld}" valueType="string"/>
 								<inputType id="com.st.stm32cube.ide.mcu.gnu.managedbuild.tool.c.linker.input.296230319" superClass="com.st.stm32cube.ide.mcu.gnu.managedbuild.tool.c.linker.input">
 									<additionalInput kind="additionalinputdependency" paths="$(USER_OBJS)"/>
 									<additionalInput kind="additionalinput" paths="$(LIBS)"/>
diff --git a/STM32F407VGTX_FLASH_custom.ld b/STM32F407VGTX_FLASH_custom.ld
new file mode 100644
index 0000000..38d48f1
--- /dev/null
+++ b/STM32F407VGTX_FLASH_custom.ld
@@ -0,0 +1,209 @@
+/*
+******************************************************************************
+**
+** @file        : LinkerScript.ld
+**
+** @author      : Auto-generated by STM32CubeIDE
+**
+**  Abstract    : Linker script for STM32F407G-DISC1 Board embedding STM32F407VGTx Device from stm32f4 series
+**                      1024KBytes FLASH
+**                      64KBytes CCMRAM
+**                      128KBytes RAM
+**
+**                Set heap size, stack size and stack location according
+**                to application requirements.
+**
+**                Set memory bank area and size if external memory is used
+**
+**  Target      : STMicroelectronics STM32
+**
+**  Distribution: The file is distributed as is, without any warranty
+**                of any kind.
+**
+******************************************************************************
+** @attention
+**
+** Copyright (c) 2024 STMicroelectronics.
+** All rights reserved.
+**
+** This software is licensed under terms that can be found in the LICENSE file
+** in the root directory of this software component.
+** If no LICENSE file comes with this software, it is provided AS-IS.
+**
+******************************************************************************
+*/
+
+/* Entry Point */
+ENTRY(Reset_Handler)
+
+/* Highest address of the user mode stack */
+_estack = ORIGIN(RAM) + LENGTH(RAM); /* end of "RAM" Ram type memory */
+
+_Min_Heap_Size = 0x200; /* required amount of heap */
+_Min_Stack_Size = 0x400; /* required amount of stack */
+
+/* Memories definition */
+MEMORY
+{
+  CCMRAM     (xrw)    : ORIGIN = 0x10000000,  LENGTH = 64K
+  RAM        (xrw)    : ORIGIN = 0x20000000,  LENGTH = 128K
+  FLASH_BOOT  (rx)    : ORIGIN = 0x8000000,   LENGTH = 16K
+  FLASH       (rx)    : ORIGIN = 0x8008000,   LENGTH = 992K
+}
+
+/* Sections */
+SECTIONS
+{
+  /* The startup code into "FLASH" Rom type memory */
+  .isr_vector :
+  {
+    . = ALIGN(4);
+    KEEP(*(.isr_vector)) /* Startup code */
+    . = ALIGN(4);
+  } >FLASH_BOOT
+
+  /* The program code and other data into "FLASH" Rom type memory */
+  .text :
+  {
+    . = ALIGN(4);
+    *(.text)           /* .text sections (code) */
+    *(.text*)          /* .text* sections (code) */
+    *(.glue_7)         /* glue arm to thumb code */
+    *(.glue_7t)        /* glue thumb to arm code */
+    *(.eh_frame)
+
+    KEEP (*(.init))
+    KEEP (*(.fini))
+
+    . = ALIGN(4);
+    _etext = .;        /* define a global symbols at end of code */
+  } >FLASH
+
+  /* Constant data into "FLASH" Rom type memory */
+  .rodata :
+  {
+    . = ALIGN(4);
+    *(.rodata)         /* .rodata sections (constants, strings, etc.) */
+    *(.rodata*)        /* .rodata* sections (constants, strings, etc.) */
+    . = ALIGN(4);
+  } >FLASH
+
+  .ARM.extab (READONLY) : /* The "READONLY" keyword is only supported in GCC11 and later, remove it if using GCC10 or earlier. */
+  {
+    . = ALIGN(4);
+    *(.ARM.extab* .gnu.linkonce.armextab.*)
+    . = ALIGN(4);
+  } >FLASH
+
+  .ARM (READONLY) : /* The "READONLY" keyword is only supported in GCC11 and later, remove it if using GCC10 or earlier. */
+  {
+    . = ALIGN(4);
+    __exidx_start = .;
+    *(.ARM.exidx*)
+    __exidx_end = .;
+    . = ALIGN(4);
+  } >FLASH
+
+  .preinit_array (READONLY) : /* The "READONLY" keyword is only supported in GCC11 and later, remove it if using GCC10 or earlier. */
+  {
+    . = ALIGN(4);
+    PROVIDE_HIDDEN (__preinit_array_start = .);
+    KEEP (*(.preinit_array*))
+    PROVIDE_HIDDEN (__preinit_array_end = .);
+    . = ALIGN(4);
+  } >FLASH
+
+  .init_array (READONLY) : /* The "READONLY" keyword is only supported in GCC11 and later, remove it if using GCC10 or earlier. */
+  {
+    . = ALIGN(4);
+    PROVIDE_HIDDEN (__init_array_start = .);
+    KEEP (*(SORT(.init_array.*)))
+    KEEP (*(.init_array*))
+    PROVIDE_HIDDEN (__init_array_end = .);
+    . = ALIGN(4);
+  } >FLASH
+
+  .fini_array (READONLY) : /* The "READONLY" keyword is only supported in GCC11 and later, remove it if using GCC10 or earlier. */
+  {
+    . = ALIGN(4);
+    PROVIDE_HIDDEN (__fini_array_start = .);
+    KEEP (*(SORT(.fini_array.*)))
+    KEEP (*(.fini_array*))
+    PROVIDE_HIDDEN (__fini_array_end = .);
+    . = ALIGN(4);
+  } >FLASH
+
+  /* Used by the startup to initialize data */
+  _sidata = LOADADDR(.data);
+
+  /* Initialized data sections into "RAM" Ram type memory */
+  .data :
+  {
+    . = ALIGN(4);
+    _sdata = .;        /* create a global symbol at data start */
+    *(.data)           /* .data sections */
+    *(.data*)          /* .data* sections */
+    *(.RamFunc)        /* .RamFunc sections */
+    *(.RamFunc*)       /* .RamFunc* sections */
+
+    . = ALIGN(4);
+    _edata = .;        /* define a global symbol at data end */
+
+  } >RAM AT> FLASH
+
+  _siccmram = LOADADDR(.ccmram);
+
+  /* CCM-RAM section
+  *
+  * IMPORTANT NOTE!
+  * If initialized variables will be placed in this section,
+  * the startup code needs to be modified to copy the init-values.
+  */
+  .ccmram :
+  {
+    . = ALIGN(4);
+    _sccmram = .;       /* create a global symbol at ccmram start */
+    *(.ccmram)
+    *(.ccmram*)
+
+    . = ALIGN(4);
+    _eccmram = .;       /* create a global symbol at ccmram end */
+  } >CCMRAM AT> FLASH
+
+  /* Uninitialized data section into "RAM" Ram type memory */
+  . = ALIGN(4);
+  .bss :
+  {
+    /* This is used by the startup in order to initialize the .bss section */
+    _sbss = .;         /* define a global symbol at bss start */
+    __bss_start__ = _sbss;
+    *(.bss)
+    *(.bss*)
+    *(COMMON)
+
+    . = ALIGN(4);
+    _ebss = .;         /* define a global symbol at bss end */
+    __bss_end__ = _ebss;
+  } >RAM
+
+  /* User_heap_stack section, used to check that there is enough "RAM" Ram  type memory left */
+  ._user_heap_stack :
+  {
+    . = ALIGN(8);
+    PROVIDE ( end = . );
+    PROVIDE ( _end = . );
+    . = . + _Min_Heap_Size;
+    . = . + _Min_Stack_Size;
+    . = ALIGN(8);
+  } >RAM
+
+  /* Remove information from the compiler libraries */
+  /DISCARD/ :
+  {
+    libc.a ( * )
+    libm.a ( * )
+    libgcc.a ( * )
+  }
+
+  .ARM.attributes 0 : { *(.ARM.attributes) }
+}

From a7736d325be76f1293f415def8d9a095a7c891e9 Mon Sep 17 00:00:00 2001
From: hasslesstech <hasslesstech@tutanota.com>
Date: Sun, 28 Dec 2025 21:55:01 +0200
Subject: [PATCH 2/9] Issue #26: Add python3 script for automatical
 ulDatabase.h metadata enum updations with included validation measures

---
 .../Database/scripts/updateMetadataEnum.py    | 218 ++++++++++++++++++
 1 file changed, 218 insertions(+)
 create mode 100755 KPI_Rover/Database/scripts/updateMetadataEnum.py

diff --git a/KPI_Rover/Database/scripts/updateMetadataEnum.py b/KPI_Rover/Database/scripts/updateMetadataEnum.py
new file mode 100755
index 0000000..1f8358c
--- /dev/null
+++ b/KPI_Rover/Database/scripts/updateMetadataEnum.py
@@ -0,0 +1,218 @@
+#!/bin/python3
+
+from pathlib import Path
+
+lines = open(Path(__file__).parent / "../../KPIRover.c").read().split('\n')
+
+decoder_active = False
+
+params = []
+
+def log(text):
+    types = {"ERROR": True,
+             "WARN": True,
+             "INFO": True,
+             "DEBUG": True}
+
+    if len(text) == 0 or text[0] != "[":
+        print(text)
+        return
+
+    msg_type = text.split("]", 1)[0][1:]
+
+    if msg_type not in types:
+        print(f'[INTERNAL ERROR] msg_type "{msg_type}" does not exist')
+        exit(2)
+
+    if types[msg_type]:
+        print(text)
+
+def process_offset(v):
+    global params
+
+    offset = int(v)
+
+    if offset != 0:
+        log("[WARN] Offsets are overridden by the database and should be kept as 0 in the metadata")
+        return False
+
+    params[-1]["offset"] = int(v)
+
+    return True
+
+def process_type(v):
+    global params
+
+    if v not in ["INT8", "UINT8", "INT16", "UINT16", "INT32", "UINT32", "FLOAT"]:
+        log(f'[ERROR] Invalid type: "{v}"')
+        return False
+
+    params[-1]["type"] = v
+
+    return True
+
+def process_persistent(v):
+    global params
+
+    if v not in ["true", "false"]:
+        log(f"[ERROR] Invalid boolean value: {v}")
+        return False
+
+    params[-1]["persistent"] = True if v == "true" else False
+
+    if len(params) > 1:
+        if params[-1]["persistent"] and not params[-2]["persistent"]:
+            log("[ERROR] Persistent parameters must come before the non-persistent ones")
+            return False
+
+    return True
+
+def process_defaultValue(v):
+    if params[-1]["type"] == "FLOAT":
+        try:
+            params[-1]["defaultValue"] = float(v.strip("fF"))
+        except:
+            log(f"[ERROR] Invalid floating-point value: {v}")
+            return False
+    else:
+        try:
+            params[-1]["defaultValue"] = int(v)
+        except:
+            log(f"[ERROR] Invalid integer value: {v}")
+            return False
+
+    ''' unfinished and broken, no reason to fix right now
+    elif params[-1]["type"] == "INT32":
+        try:
+            params[-1]["defaultValue"] = int(v)
+
+            if params[-1]["defaultValue"] > 0x7fffffff:
+                print(f"[WARN] defaultValue overflows it's data type: {v} ({hex(params[-1]['defaultValue'])}) > 0x7fffffff")
+            elif params[-1]["defaultValue"] < -0x80000000:
+                print(f"[WARN] defaultValue overflows it's data type: {v} ({hex(params[-1]['defaultValue'] % 0x100000000)}) < -0x80000000")
+        except:
+            log(f"[ERROR] Invalid floating-point value: {v}")
+            return False
+    '''
+
+    return True
+
+for l in lines:
+    log("> " + l)
+    if 'struct ulDatabase_ParamMetadata ulDatabase_params[]' in l:
+        log("[DEBUG] Starting to read metadata")
+        decoder_active = True
+        continue
+
+    if ('}' in l) and ('{' not in l):
+        log("[DEBUG] End of metadata")
+        break
+
+    if not decoder_active:
+        continue
+
+    metadata = [i.strip() for i in l.split('}')[0].split('{')[1].split(',')]
+    name = l.split("//")[1].strip().strip(",")
+
+    params.append({'name': name})
+
+    metadata_item_pool = [
+        {
+            "name": "offset",
+            "func": process_offset
+        },
+        {
+            "name": "type",
+            "func": process_type
+        },
+        {
+            "name": "persistent",
+            "func": process_persistent
+        },
+        {
+            "name": "defaultValue",
+            "func": process_defaultValue
+        }
+    ]
+
+    for i, v in enumerate(metadata_item_pool):
+        v["position"] = i
+
+    for c, t in enumerate(metadata):
+        index = -1
+        result = False
+        value = ""
+
+        if '=' in t:
+            item, value = [i.strip() for i in t.split("=")]
+            
+            try:
+                index = [i['name'] for i in metadata_item_pool].index(item)
+            except ValueError:
+                log(f'[ERROR] {i}: "{item}": no such metadata key')
+        else:
+            index = 0
+            value = t
+
+        if index != -1:
+            result = metadata_item_pool.pop(index)['func'](value)
+
+        if not result:
+            unwrapped_l = l.replace("\t", " " * 8)
+            log(f"[ERROR] > {unwrapped_l}")
+
+            arrow_offset = unwrapped_l.index("{") + 1
+            ll = unwrapped_l[arrow_offset:]
+
+            for _ in range(c):
+                arrow_offset += ll.index(",") + 1
+                ll = unwrapped_l[arrow_offset:]
+
+            while unwrapped_l[arrow_offset] == ' ':
+                arrow_offset += 1
+
+            underline_len = len(t) - 1
+
+            while unwrapped_l[arrow_offset + underline_len] == ' ':
+                underline_len -= 1
+
+            log("[ERROR] > " + " " * arrow_offset + "^" + "~" * underline_len)
+            log("[ERROR] Error detected, not continuing")
+            exit(1)
+
+log("[INFO] Result:")
+
+for i in params:
+    print("[INFO] " + i["name"])
+
+
+log("[INFO] Patching ulDatabase.h...")
+
+ulDatabase_h = open(Path(__file__).parent / "../ulDatabase.h").read().split('\n')
+while ulDatabase_h[-1] == "":
+    del ulDatabase_h[-1]
+
+enum_since = [i.startswith("enum ulDatabase_ParamId {") for i in ulDatabase_h].index(True) + 1
+enum_len = [i.startswith("};") for i in ulDatabase_h[enum_since:]].index(True)
+
+log("[DEBUG]: Removing old enum data:")
+for i, l in enumerate(ulDatabase_h):
+    if enum_since <= i < enum_since + enum_len:
+        log("[DEBUG] -" + l)
+    else:
+        log("[DEBUG]  " + l)
+
+del ulDatabase_h[enum_since:enum_since+enum_len]
+
+ulDatabase_h.insert(enum_since, "\tPARAM_COUNT")
+for i in params[::-1]:
+    ulDatabase_h.insert(enum_since, f"\t{i['name']},")
+
+log("[DEBUG] Writing new ulDatabase.h...")
+
+with open(Path(__file__).parent / "../ulDatabase.h", "w") as f:
+    for i in ulDatabase_h:
+        print(i + '\n', end = '')
+        f.write(i + '\n')
+
+log("[DEBUG] ulDatabase.h closed")

From 8ae87538007e0c5d70d9d2eaf46dc7571e0dd30f Mon Sep 17 00:00:00 2001
From: hasslesstech <hasslesstech@tutanota.com>
Date: Tue, 30 Dec 2025 15:43:44 +0200
Subject: [PATCH 3/9] Issue #26: [wip] Add draft code for ulStorage, add
 mandatory API in ulDatabase

---
 KPI_Rover/Database/ulDatabase.c |  14 +
 KPI_Rover/Database/ulDatabase.h |   2 +
 KPI_Rover/Database/ulStorage.c  | 483 ++++++++++++++++++++++++++++++++
 KPI_Rover/Database/ulStorage.h  |  11 +
 4 files changed, 510 insertions(+)
 create mode 100644 KPI_Rover/Database/ulStorage.c
 create mode 100644 KPI_Rover/Database/ulStorage.h

diff --git a/KPI_Rover/Database/ulDatabase.c b/KPI_Rover/Database/ulDatabase.c
index 80e69c1..99b8b86 100644
--- a/KPI_Rover/Database/ulDatabase.c
+++ b/KPI_Rover/Database/ulDatabase.c
@@ -403,6 +403,20 @@ bool ulDatabase_reset(uint16_t id)
 	return true;
 }
 
+uint8_t *ulDatabase_freeze(void)
+{
+	DB_LOCK();
+
+	return db.dataArray;
+}
+
+bool ulDatabase_unfreeze(void)
+{
+	DB_FREE();
+
+	return true;
+}
+
 struct ulDatabase_ParamMetadata *ulDatabase_getMetadata(uint16_t id)
 {
 	if (!ulDatabase_validateId(id))
diff --git a/KPI_Rover/Database/ulDatabase.h b/KPI_Rover/Database/ulDatabase.h
index 724e9ec..b5d098d 100644
--- a/KPI_Rover/Database/ulDatabase.h
+++ b/KPI_Rover/Database/ulDatabase.h
@@ -56,5 +56,7 @@ bool ulDatabase_getInt32(uint16_t id, int32_t *value);
 bool ulDatabase_setFloat(uint16_t id, float value);
 bool ulDatabase_getFloat(uint16_t id, float *value);
 bool ulDatabase_reset(uint16_t id);
+uint8_t *ulDatabase_freeze(void);
+void ulDatabase_unfreeze(void);
 struct ulDatabase_ParamMetadata *ulDatabase_getMetadata(uint16_t id);
 bool ulDatabase_validateId(uint16_t id);
diff --git a/KPI_Rover/Database/ulStorage.c b/KPI_Rover/Database/ulStorage.c
new file mode 100644
index 0000000..92f8052
--- /dev/null
+++ b/KPI_Rover/Database/ulStorage.c
@@ -0,0 +1,483 @@
+#include <string.h>
+
+#include "ulDatabase.h"
+#include "ulStorage.h"
+
+#include "ulog.h"
+
+#define PAGE_START 0x10000000	// CCM RAM
+#define PAGE_SIZE 0x4000	// 16KiB to emulate flash sector (CCM RAM is 64KiB)
+#define MARKER_SAVE_BEGIN 0xAA
+
+static uint32_t persistent_db_field_size;
+
+
+// debug start
+static bool flash_unlocked;
+
+static void HAL_FLASH_Unlock(void)
+{
+	flash_unlocked = 1;
+}
+
+static void HAL_FLASH_Lock(void)
+{
+	flash_unlocked = 0;
+}
+// debug end
+
+
+enum Size {
+	FLASH_TYPEPROGRAM_BYTE
+};
+
+static void HAL_FLASH_Erase(void)
+{
+	if (!flash_unlocked) {
+		ULOG_WARNING("Erase command on locked flash");
+		return;
+	}
+
+	memset((void *) PAGE_START, 0xFF, PAGE_SIZE);
+}
+
+static void HAL_FLASH_Program(enum Size s, const void * const addr, const uint64_t value)
+{
+	(void) s;
+
+	if (!flash_unlocked) {
+		ULOG_WARNING("Write command on locked flash: %p <- 0x%02hhx", addr, (uint8_t) value);
+		return;
+	}
+
+	if ((addr >= (void *) (PAGE_START + PAGE_SIZE)) || (addr < (void *) PAGE_START)) {
+		ULOG_CRITICAL("OUT OF BOUNDS FLASH WRITE GENERATED");
+		ULOG_CRITICAL("TRIED TO WRITE VALUE 0x%02hhx TO ADDRESS %p", (uint8_t) value, addr);
+		return;
+	}
+
+	*(uint8_t *) addr = (uint8_t) value;
+}
+
+static uint32_t crc32(const uint8_t * const data, const uint32_t data_size, const uint32_t remainder)
+{
+    register uint32_t reg_a = 0,
+                      reg_b = 0;
+
+    static const uint32_t divisor = 0x04C11DB7;
+
+    uint32_t read_offset = 0;
+    uint32_t xor_ready = 0;
+
+    while ((data_size - read_offset) >= 4) {
+        reg_b = *(uint32_t *) &(data[read_offset]);
+        read_offset += 4;
+
+        for (unsigned int i = 0; i < 32; i++) {
+            // check if XOR can be done yet
+            xor_ready = reg_a & 0x80000000;
+
+            // shift in
+            reg_a <<= 1;
+
+            if (reg_b & 0x80000000)
+                reg_a |= 0x1;
+
+            reg_b <<= 1;
+
+            // XOR if ready
+            if (xor_ready)
+                reg_a ^= divisor;
+        }
+    }
+
+    if (data_size - read_offset != 0) {
+        // fill reg_b
+        for (unsigned int i = 0; i < (data_size - read_offset); i++) {
+            reg_b |= data[read_offset + i];
+            reg_b <<= 8;
+        }
+
+        reg_b <<= 8 * (3 - (data_size - read_offset));
+
+        // finish calculating main part
+        for (unsigned int i = 0; i < 8 * (data_size - read_offset); i++) {
+            // check if XOR can be done yet
+            xor_ready = reg_a & 0x80000000;
+
+            // shift in
+            reg_a <<= 1;
+
+            if (reg_b & 0x80000000)
+                reg_a |= 0x1;
+
+            reg_b <<= 1;
+
+            // XOR if ready
+            if (xor_ready)
+                reg_a ^= divisor;
+        }
+    }
+
+    // now finish with 32 bits of the remainder
+    reg_b = remainder;
+
+    // finish calculating main part
+    for (unsigned int i = 0; i < 32; i++) {
+        // check if XOR can be done yet
+        xor_ready = reg_a & 0x80000000;
+
+        // shift in
+        reg_a <<= 1;
+
+        if (reg_b & 0x80000000)
+            reg_a |= 0x1;
+
+        reg_b <<= 1;
+
+        // XOR if ready
+        if (xor_ready)
+            reg_a ^= divisor;
+    }
+
+    return reg_a;
+}
+
+static uint32_t crc32_calculate(const uint8_t * const data, const uint32_t data_size)
+{
+    return crc32(data, data_size, 0);
+}
+
+static uint32_t crc32_verify(const uint8_t * const data, const uint32_t data_size, const uint32_t remainder)
+{
+    return crc32(data, data_size, remainder);
+}
+
+static uint32_t ulStorage_get_save_size(void)
+{
+	uint32_t persistent_fields_len = 0;
+
+	for (uint16_t i = 0; i < PARAM_COUNT; i++) {
+		struct ulDatabase_ParamMetadata *p = ulDatabase_getMetadata(i);
+
+		if (p == NULL)
+			return false;
+
+		if (!p->persistent)
+			break;
+
+		switch (p->type) {
+		case INT8:
+		case UINT8:
+			persistent_fields_len += 1;
+			break;
+		case INT16:
+		case UINT16:
+			persistent_fields_len += 2;
+			break;
+		case INT32:
+		case UINT32:
+		case FLOAT:
+			persistent_fields_len += 4;
+			break;
+		}
+	}
+
+	return persistent_fields_len;
+}
+
+static bool ulStorage_verify_sector_header(void)
+{
+	uint32_t sector_header = *(uint32_t *) PAGE_START;
+
+	// verify the sector is erased
+	if (sector_header & 0x80) {
+		ULOG_WARNING("Sector is not formatted: ERASED flag is 1");
+		return false;
+	}
+
+	// verify no invalid flags are present
+	if ((sector_header & 0x2F) != 0x2F) {
+		ULOG_WARNING("Sector is not formatted: garbage flags found");
+		return false;
+	}
+
+	// verify save size matches current persistent field size
+	if ((sector_header >> 20) != persistent_db_field_size) {
+		ULOG_WARNING("Save size does not match with current size");
+		return false;
+	}
+
+	// verify hash is not there yet
+	if ((sector_header & 0x000FFF00) != 0x000FFF00) {
+		ULOG_WARNING("Garbage found in HASH header field");
+		return false;
+	}
+
+	return true;
+}
+
+static uint8_t *ulStorage_find_first_free_block(void)
+{
+	uint8_t *seek_head;
+
+	for (
+		seek_head = (uint8_t *) PAGE_START + 4;
+		(seek_head < (uint8_t *) (PAGE_START + PAGE_SIZE)) && (*seek_head == MARKER_SAVE_BEGIN);
+		seek_head += 1 + persistent_db_field_size + 4);
+
+	return seek_head;
+}
+
+static bool ulStorage_find_last_save(uint8_t **buffer)
+{
+	// --- Verify sector header ---
+
+	/*
+	uint32_t sector_header = *(uint32_t *) PAGE_START;
+
+	// verify the sector is erased
+	if (sector_header & 0x80) {
+		ULOG_WARNING("Sector is not formatted: ERASED flag is 1");
+		return false;
+	}
+
+	// verify no invalid flags are present
+	if ((sector_header & 0x2F) != 0x2F) {
+		ULOG_WARNING("Sector is not formatted: garbage flags found");
+		return false;
+	}
+
+	// verify save size matches current persistent field size
+	if ((sector_header >> 20) != persistent_db_field_size) {
+		ULOG_WARNING("Save size does not match with current size");
+		return false;
+	}
+
+	// verify hash is not there yet
+	if ((sector_header & 0x00FFFFF000) != 0x00FFFFF000) {
+		ULOG_WARNING("Garbage found in HASH header field");
+		return false;
+	}
+	*/
+
+	if (!ulStorage_verify_sector_header())
+		return false;
+
+	// --- Find last valid save ---
+
+	//uint8_t *seek_head = PAGE_START + 4,
+	//	*last_save_header == NULL;
+	uint8_t *seek_head = ulStorage_find_first_free_block();
+
+	// initial seek to first non-marked position
+	/*
+	for (
+		seek_head = (uint8_t *) PAGE_START + 4;
+		(seek_head < (uint8_t *) (PAGE_START + PAGE_SIZE)) && (*seek_head == MARKER_SAVE_BEGIN);
+		seek_head += 1 + persistent_db_field_size + 4);
+	*/
+	/*
+	for (
+		uint8_t *seek_head = (uint8_t *) PAGE_START + 4, *last_save_header = NULL;
+		(seek_head < (uint8_t *)(PAGE_START + PAGE_SIZE)) && (*seek_head == MARKER_SAVE_BEGIN);
+		last_save_header = seek_head, seek_head += 1 + persistent_fields_len + 4);
+	*/
+
+	/*
+	while (seek_head < PAGE_START + PAGE_SIZE) {
+		if (*seek_head == MARKER_SAVE_BEGIN) {
+			last_save_header = seek_head;
+			seek_head += 1 + persistent_fields_len + 4;
+		} else {
+			break;
+		}
+	}
+	*/
+
+	/*
+	if (last_save_header == NULL) {
+		ULOG_WARNING("No save data is found");
+		return false;
+	}
+	*/
+
+	// finding last valid save data
+	uint32_t save_checksum = 0xFFFFFFFF;
+
+	while ((seek_head > (uint8_t *) PAGE_START + 4) && save_checksum) {
+		ULOG_DEBUG("Verifying save hash for %p", seek_head);
+
+		seek_head -= 1 + persistent_db_field_size + 4;
+		save_checksum = crc32_verify(seek_head + 1, persistent_db_field_size, *(uint32_t *)(seek_head + 1 + persistent_db_field_size));
+
+		ULOG_DEBUG("Result: 0x%08X", save_checksum);
+	}
+
+	// if none found, stop
+	if (save_checksum) {
+		ULOG_WARNING("No valid saves found");
+		return false;
+	}
+
+	/*
+	// freeze DB for exclusive access
+	uint8_t *db_data = ulDatabase_freeze();
+	ulDatabase_unfreeze();
+	*/
+
+	// otherwise set the correct pointer
+	*buffer = seek_head + 1;
+
+	return true;
+}
+
+static bool ulStorage_find_new_save_block(uint8_t ** block)
+{
+	if (!ulStorage_verify_sector_header())
+		return false;
+
+	uint8_t *new_block = ulStorage_find_first_free_block();
+
+	if (new_block >= (uint8_t *) (PAGE_START + PAGE_SIZE))
+		return false;
+
+	*block = new_block;
+
+	return true;
+}
+
+static void ulStorage_format_sector(void)
+{
+	uint32_t new_header = 0xFFFFFFFF;
+
+	// mark ERASED bit
+	new_header &= 0xFFFFFF7F;
+
+	// mark save size
+	new_header &= (persistent_db_field_size << 20) | (0x000FFFFF);
+
+	// --- ENTER UNSAFE ZONE ---
+
+	HAL_FLASH_Unlock();
+
+	HAL_FLASH_Erase();
+
+	// write header to flash
+	HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, (void *) (PAGE_START + 0), (new_header >>  0) & 0xFF);
+	HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, (void *) (PAGE_START + 1), (new_header >>  8) & 0xFF);
+	HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, (void *) (PAGE_START + 2), (new_header >> 16) & 0xFF);
+	HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, (void *) (PAGE_START + 3), (new_header >> 24) & 0xFF);
+
+	HAL_FLASH_Lock();
+
+	// --- LEAVE UNSAFE ZONE ---
+}
+
+static void ulStorage_write_save(uint8_t * const write_at, const uint8_t * const save_data)
+{
+	uint32_t checksum = crc32_calculate(save_data, persistent_db_field_size);
+
+	// --- ENTER UNSAFE ZONE ---
+
+	HAL_FLASH_Unlock();
+
+	HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, save_data, MARKER_SAVE_BEGIN);
+
+	for (uint32_t i = 1; i <= persistent_db_field_size; i++)
+		HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, write_at + i, save_data[i]);
+
+	for (uint32_t i = 0; i < 4; i++)
+		HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, write_at + 1 + persistent_db_field_size + i, (checksum >> (8 * i)) & 0xFF);
+
+	HAL_FLASH_Lock();
+
+	// --- LEAVE UNSAFE ZONE ---
+}
+
+bool ulStorage_init(void)
+{
+	persistent_db_field_size = ulStorage_get_save_size();
+
+	return true;
+}
+
+bool ulStorage_load(void)
+{
+	if (!persistent_db_field_size)
+		return true;
+
+	uint8_t *buffer;
+
+	if (!ulStorage_find_last_save(&buffer))
+		return false;
+
+	uint8_t *db_data = ulDatabase_freeze();
+	memcpy(db_data, buffer, persistent_db_field_size);
+	ulDatabase_unfreeze();
+
+	return true;
+}
+
+bool ulStorage_save(void)
+{
+	if (!persistent_db_field_size)
+		return true;
+
+	// get a copy of persistent fields
+	uint8_t new_save_data[persistent_db_field_size];
+
+	uint8_t *db_data = ulDatabase_freeze();
+	memcpy(new_save_data, db_data, persistent_db_field_size);
+	ulDatabase_unfreeze();
+
+	// try to load last save
+	uint8_t *last_save_data;
+	if (ulStorage_find_last_save(&last_save_data))
+		if (!memcmp(new_save_data, last_save_data, persistent_db_field_size)) {
+			ULOG_INFO("Old save is valid and identical to a new one; not writing another block");
+			return true;
+		}
+
+	// write a new save
+	uint8_t *new_save_address;
+
+	if (!ulStorage_find_new_save_block(&new_save_address)) {
+		// the storage is not formatted or is full - either way needs formatting
+		ULOG_INFO("Sector is full or not formatted; formatting the sector and writing new save");
+		ulStorage_format_sector();
+		ulStorage_write_save((uint8_t *) (PAGE_START + 4), new_save_data);
+	} else {
+		ULOG_INFO("Writing new save to %p", new_save_address);
+		ulStorage_write_save(new_save_address, new_save_data);
+	}
+
+	return false;
+}
+
+bool ulStorage_erase(void)
+{
+	if (!persistent_db_field_size)
+		return true;
+
+	ulStorage_format_sector();
+
+	return true;
+}
+
+bool ulStorage_factoryReset(void)
+{
+	//struct ulDatabase_ParamMetadata *p;
+
+	//for (uint16_t i = 0; p = ulDatabase_getMetadata(i), (p != NULL) && (!p->persistent); ulDatabase_ i++)
+	//for (uint16_t i = 0; (p = ulDatabase_getMetadata(i)) != NULL; ulDatabase_reset(i), i++);
+
+	for (uint16_t i = 0; ulDatabase_reset(i); i++);
+
+	if (!persistent_db_field_size)
+		return true;
+
+	ulStorage_format_sector();
+
+	return true;
+}
diff --git a/KPI_Rover/Database/ulStorage.h b/KPI_Rover/Database/ulStorage.h
new file mode 100644
index 0000000..a20f81e
--- /dev/null
+++ b/KPI_Rover/Database/ulStorage.h
@@ -0,0 +1,11 @@
+#ifndef __ULSTORAGE_H
+#define __ULSTORAGE_H
+
+#include <stdbool.h>
+
+bool ulStorage_load(void);
+bool ulStorage_save(void);
+bool ulStorage_erase(void);
+bool ulStorage_factoryReset(void);
+
+#endif /* __ULSTORAGE_H */

From 3a0a8252881335ac9bd9d139a317fe94ac09d92e Mon Sep 17 00:00:00 2001
From: hasslesstech <hasslesstech@tutanota.com>
Date: Thu, 8 Jan 2026 20:33:07 +0200
Subject: [PATCH 4/9] Issue #26: bugfixes and general improvements

---
 KPI_Rover/Database/ulDatabase.c |  4 +--
 KPI_Rover/Database/ulStorage.c  | 46 +++++++++++++++++++++++++--------
 KPI_Rover/Database/ulStorage.h  |  1 +
 3 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/KPI_Rover/Database/ulDatabase.c b/KPI_Rover/Database/ulDatabase.c
index 99b8b86..fe664a4 100644
--- a/KPI_Rover/Database/ulDatabase.c
+++ b/KPI_Rover/Database/ulDatabase.c
@@ -410,11 +410,9 @@ uint8_t *ulDatabase_freeze(void)
 	return db.dataArray;
 }
 
-bool ulDatabase_unfreeze(void)
+void ulDatabase_unfreeze(void)
 {
 	DB_FREE();
-
-	return true;
 }
 
 struct ulDatabase_ParamMetadata *ulDatabase_getMetadata(uint16_t id)
diff --git a/KPI_Rover/Database/ulStorage.c b/KPI_Rover/Database/ulStorage.c
index 92f8052..c541665 100644
--- a/KPI_Rover/Database/ulStorage.c
+++ b/KPI_Rover/Database/ulStorage.c
@@ -12,7 +12,7 @@
 static uint32_t persistent_db_field_size;
 
 
-// debug start
+// flash emulation section start
 static bool flash_unlocked;
 
 static void HAL_FLASH_Unlock(void)
@@ -24,8 +24,6 @@ static void HAL_FLASH_Lock(void)
 {
 	flash_unlocked = 0;
 }
-// debug end
-
 
 enum Size {
 	FLASH_TYPEPROGRAM_BYTE
@@ -58,6 +56,7 @@ static void HAL_FLASH_Program(enum Size s, const void * const addr, const uint64
 
 	*(uint8_t *) addr = (uint8_t) value;
 }
+// flash emulation section finish
 
 static uint32_t crc32(const uint8_t * const data, const uint32_t data_size, const uint32_t remainder)
 {
@@ -223,7 +222,7 @@ static uint8_t *ulStorage_find_first_free_block(void)
 
 	for (
 		seek_head = (uint8_t *) PAGE_START + 4;
-		(seek_head < (uint8_t *) (PAGE_START + PAGE_SIZE)) && (*seek_head == MARKER_SAVE_BEGIN);
+		(seek_head < (uint8_t *) (PAGE_START + PAGE_SIZE)) && (*seek_head != 0xFF);
 		seek_head += 1 + persistent_db_field_size + 4);
 
 	return seek_head;
@@ -306,11 +305,10 @@ static bool ulStorage_find_last_save(uint8_t **buffer)
 	uint32_t save_checksum = 0xFFFFFFFF;
 
 	while ((seek_head > (uint8_t *) PAGE_START + 4) && save_checksum) {
+		seek_head -= 1 + persistent_db_field_size + 4;
 		ULOG_DEBUG("Verifying save hash for %p", seek_head);
 
-		seek_head -= 1 + persistent_db_field_size + 4;
 		save_checksum = crc32_verify(seek_head + 1, persistent_db_field_size, *(uint32_t *)(seek_head + 1 + persistent_db_field_size));
-
 		ULOG_DEBUG("Result: 0x%08X", save_checksum);
 	}
 
@@ -339,7 +337,7 @@ static bool ulStorage_find_new_save_block(uint8_t ** block)
 
 	uint8_t *new_block = ulStorage_find_first_free_block();
 
-	if (new_block >= (uint8_t *) (PAGE_START + PAGE_SIZE))
+	if ((new_block + 1 + persistent_db_field_size + 4) >= (uint8_t *) (PAGE_START + PAGE_SIZE))
 		return false;
 
 	*block = new_block;
@@ -382,10 +380,10 @@ static void ulStorage_write_save(uint8_t * const write_at, const uint8_t * const
 
 	HAL_FLASH_Unlock();
 
-	HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, save_data, MARKER_SAVE_BEGIN);
+	HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, write_at, MARKER_SAVE_BEGIN);
 
-	for (uint32_t i = 1; i <= persistent_db_field_size; i++)
-		HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, write_at + i, save_data[i]);
+	for (uint32_t i = 0; i < persistent_db_field_size; i++)
+		HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, write_at + 1 + i, save_data[i]);
 
 	for (uint32_t i = 0; i < 4; i++)
 		HAL_FLASH_Program(FLASH_TYPEPROGRAM_BYTE, write_at + 1 + persistent_db_field_size + i, (checksum >> (8 * i)) & 0xFF);
@@ -399,6 +397,13 @@ bool ulStorage_init(void)
 {
 	persistent_db_field_size = ulStorage_get_save_size();
 
+	bool r = ulStorage_load();
+	if (r) {
+		ULOG_INFO("Loaded save from storage");
+	} else {
+		ULOG_INFO("Loading save from storage has failed");
+	}
+
 	return true;
 }
 
@@ -452,7 +457,7 @@ bool ulStorage_save(void)
 		ulStorage_write_save(new_save_address, new_save_data);
 	}
 
-	return false;
+	return true;
 }
 
 bool ulStorage_erase(void)
@@ -473,6 +478,25 @@ bool ulStorage_factoryReset(void)
 	//for (uint16_t i = 0; (p = ulDatabase_getMetadata(i)) != NULL; ulDatabase_reset(i), i++);
 
 	for (uint16_t i = 0; ulDatabase_reset(i); i++);
+	
+	/*
+	uint16_t i = 0;
+	while (ulDatabase_reset(i)) {
+		i++;
+	}
+
+	uint16_t i = 0;
+	bool r = true;
+	while (1) {
+		r = ulDatabase_reset(i);
+
+		if (!r) {
+			break
+		}
+
+		i++;
+	}
+	*/
 
 	if (!persistent_db_field_size)
 		return true;
diff --git a/KPI_Rover/Database/ulStorage.h b/KPI_Rover/Database/ulStorage.h
index a20f81e..7fb32a7 100644
--- a/KPI_Rover/Database/ulStorage.h
+++ b/KPI_Rover/Database/ulStorage.h
@@ -3,6 +3,7 @@
 
 #include <stdbool.h>
 
+bool ulStorage_init(void);
 bool ulStorage_load(void);
 bool ulStorage_save(void);
 bool ulStorage_erase(void);

From 2539608e012c427e7d588705accf418e34dbcbb6 Mon Sep 17 00:00:00 2001
From: hasslesstech <hasslesstech@tutanota.com>
Date: Thu, 8 Jan 2026 20:55:03 +0200
Subject: [PATCH 5/9] Issue #26: code cleanup

---
 KPI_Rover/Database/ulStorage.c | 96 ----------------------------------
 1 file changed, 96 deletions(-)

diff --git a/KPI_Rover/Database/ulStorage.c b/KPI_Rover/Database/ulStorage.c
index c541665..44a4f30 100644
--- a/KPI_Rover/Database/ulStorage.c
+++ b/KPI_Rover/Database/ulStorage.c
@@ -230,77 +230,11 @@ static uint8_t *ulStorage_find_first_free_block(void)
 
 static bool ulStorage_find_last_save(uint8_t **buffer)
 {
-	// --- Verify sector header ---
-
-	/*
-	uint32_t sector_header = *(uint32_t *) PAGE_START;
-
-	// verify the sector is erased
-	if (sector_header & 0x80) {
-		ULOG_WARNING("Sector is not formatted: ERASED flag is 1");
-		return false;
-	}
-
-	// verify no invalid flags are present
-	if ((sector_header & 0x2F) != 0x2F) {
-		ULOG_WARNING("Sector is not formatted: garbage flags found");
-		return false;
-	}
-
-	// verify save size matches current persistent field size
-	if ((sector_header >> 20) != persistent_db_field_size) {
-		ULOG_WARNING("Save size does not match with current size");
-		return false;
-	}
-
-	// verify hash is not there yet
-	if ((sector_header & 0x00FFFFF000) != 0x00FFFFF000) {
-		ULOG_WARNING("Garbage found in HASH header field");
-		return false;
-	}
-	*/
-
 	if (!ulStorage_verify_sector_header())
 		return false;
 
-	// --- Find last valid save ---
-
-	//uint8_t *seek_head = PAGE_START + 4,
-	//	*last_save_header == NULL;
 	uint8_t *seek_head = ulStorage_find_first_free_block();
 
-	// initial seek to first non-marked position
-	/*
-	for (
-		seek_head = (uint8_t *) PAGE_START + 4;
-		(seek_head < (uint8_t *) (PAGE_START + PAGE_SIZE)) && (*seek_head == MARKER_SAVE_BEGIN);
-		seek_head += 1 + persistent_db_field_size + 4);
-	*/
-	/*
-	for (
-		uint8_t *seek_head = (uint8_t *) PAGE_START + 4, *last_save_header = NULL;
-		(seek_head < (uint8_t *)(PAGE_START + PAGE_SIZE)) && (*seek_head == MARKER_SAVE_BEGIN);
-		last_save_header = seek_head, seek_head += 1 + persistent_fields_len + 4);
-	*/
-
-	/*
-	while (seek_head < PAGE_START + PAGE_SIZE) {
-		if (*seek_head == MARKER_SAVE_BEGIN) {
-			last_save_header = seek_head;
-			seek_head += 1 + persistent_fields_len + 4;
-		} else {
-			break;
-		}
-	}
-	*/
-
-	/*
-	if (last_save_header == NULL) {
-		ULOG_WARNING("No save data is found");
-		return false;
-	}
-	*/
-
 	// finding last valid save data
 	uint32_t save_checksum = 0xFFFFFFFF;
 
@@ -318,12 +252,6 @@ static bool ulStorage_find_last_save(uint8_t **buffer)
 		return false;
 	}
 
-	/*
-	// freeze DB for exclusive access
-	uint8_t *db_data = ulDatabase_freeze();
-	ulDatabase_unfreeze();
-	*/
-
 	// otherwise set the correct pointer
 	*buffer = seek_head + 1;
 
@@ -472,31 +400,7 @@ bool ulStorage_erase(void)
 
 bool ulStorage_factoryReset(void)
 {
-	//struct ulDatabase_ParamMetadata *p;
-
-	//for (uint16_t i = 0; p = ulDatabase_getMetadata(i), (p != NULL) && (!p->persistent); ulDatabase_ i++)
-	//for (uint16_t i = 0; (p = ulDatabase_getMetadata(i)) != NULL; ulDatabase_reset(i), i++);
-
 	for (uint16_t i = 0; ulDatabase_reset(i); i++);
-	
-	/*
-	uint16_t i = 0;
-	while (ulDatabase_reset(i)) {
-		i++;
-	}
-
-	uint16_t i = 0;
-	bool r = true;
-	while (1) {
-		r = ulDatabase_reset(i);
-
-		if (!r) {
-			break
-		}
-
-		i++;
-	}
-	*/
 
 	if (!persistent_db_field_size)
 		return true;

From ef13eefe81017ac80b78ac1d4c4e8b1007d62b88 Mon Sep 17 00:00:00 2001
From: hasslesstech <hasslesstech@tutanota.com>
Date: Thu, 8 Jan 2026 20:55:45 +0200
Subject: [PATCH 6/9] Issue #26: take memory address from linker script

---
 KPI_Rover/Database/ulStorage.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/KPI_Rover/Database/ulStorage.c b/KPI_Rover/Database/ulStorage.c
index 44a4f30..a787661 100644
--- a/KPI_Rover/Database/ulStorage.c
+++ b/KPI_Rover/Database/ulStorage.c
@@ -5,8 +5,10 @@
 
 #include "ulog.h"
 
-#define PAGE_START 0x10000000	// CCM RAM
-#define PAGE_SIZE 0x4000	// 16KiB to emulate flash sector (CCM RAM is 64KiB)
+extern char _sccmram[]; // value exported by linker script
+
+#define PAGE_START _sccmram	// CCM RAM (to protect actual flash memory)
+#define PAGE_SIZE 0x4000	// model 16KiB FLASH memory
 #define MARKER_SAVE_BEGIN 0xAA
 
 static uint32_t persistent_db_field_size;

From e417b0567f5adee170723808c74ae6320ed8e140 Mon Sep 17 00:00:00 2001
From: hasslesstech <hasslesstech@tutanota.com>
Date: Sat, 10 Jan 2026 23:30:13 +0200
Subject: [PATCH 7/9] ulog update 1 (name subject to change)

---
 KPI_Rover/Logger/ul_ulog.c                    | 44 ++++++++++++++-----
 .../Core/Src/usbd_core.c                      | 11 +++++
 USB_DEVICE/App/usbd_cdc_if.c                  |  7 ++-
 3 files changed, 49 insertions(+), 13 deletions(-)

diff --git a/KPI_Rover/Logger/ul_ulog.c b/KPI_Rover/Logger/ul_ulog.c
index 0238c59..a78f898 100644
--- a/KPI_Rover/Logger/ul_ulog.c
+++ b/KPI_Rover/Logger/ul_ulog.c
@@ -46,6 +46,11 @@ static StaticQueue_t xUlogQueueBuffer;
 static uint8_t ucUlogQueueStorage[LOG_QUEUE_LENGTH * MAX_LOG_MESSAGE_SIZE];
 static QueueHandle_t xULogQueue = NULL;
 
+volatile uint32_t ulogUsbIsEstablished;
+osEventFlagsId_t ulogFlags;
+#define ULOG_CDC_TRANSMIT_FINISH_FLAG 0x1
+#define ULOG_DEV_CONNECTED_WAKEUP_FLAG 0x2
+
 static const osThreadAttr_t ulogTask_attributes = {
   .name = "ulogTask",
   .stack_size = 128 * 4,
@@ -68,6 +73,8 @@ void ul_ulog_init()
   {
     Error_Handler();
   }
+
+  ulogFlags = osEventFlagsNew(NULL);
 }
 
 void ul_ulog_send(ulog_level_t level, const char *filename, char *msg)
@@ -113,21 +120,23 @@ void ul_ulog_send(ulog_level_t level, const char *filename, char *msg)
     logBuffer[sizeof(logBuffer) - 1] = '\0';
   }
   
-   BaseType_t xHigherPriorityTaskWoken = pdFALSE;
-   if (xPortIsInsideInterrupt()) {
-       xQueueSendFromISR(xULogQueue, logBuffer, &xHigherPriorityTaskWoken);
-       portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
-   } else {
-       xQueueSend(xULogQueue, logBuffer, pdMS_TO_TICKS(10));
-   }
+  BaseType_t xHigherPriorityTaskWoken = pdFALSE;
+  if (uxQueueSpacesAvailable(xULogQueue))
+  {
+    if (xPortIsInsideInterrupt())
+    {
+      xQueueSendFromISR(xULogQueue, logBuffer, &xHigherPriorityTaskWoken);
+      portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
+    }
+    else
+    {
+      xQueueSend(xULogQueue, logBuffer, pdMS_TO_TICKS(10));
+    }
+  }
 }
 
 static void ulogTask(void *argument)
 {
-  // TODO: Try to get rid of this delay
-  // Wait a bit for USB to initialize before starting logging
-  osDelay(2000);
-
   ULOG_INIT();
   ULOG_SUBSCRIBE(ul_ulog_send, ULOG_DEBUG_LEVEL);
 
@@ -139,7 +148,20 @@ static void ulogTask(void *argument)
     if (result == pdTRUE)
     {
       logMessage[MAX_LOG_MESSAGE_SIZE - 1] = '\0';
+
+      if (ulogUsbIsEstablished != 1)
+      {
+        while (ulogUsbIsEstablished != 1)
+        {
+          osEventFlagsWait(ulogFlags, ULOG_DEV_CONNECTED_WAKEUP_FLAG, 0, osWaitForever);
+          osDelay(50);
+        }
+
+        osDelay(2000);
+      }
+
       CDC_Transmit_FS((uint8_t *)logMessage, strlen(logMessage));
+      osEventFlagsWait(ulogFlags, ULOG_CDC_TRANSMIT_FINISH_FLAG, 0, 100);
     }
   }
 }
diff --git a/Middlewares/ST/STM32_USB_Device_Library/Core/Src/usbd_core.c b/Middlewares/ST/STM32_USB_Device_Library/Core/Src/usbd_core.c
index bcf571e..6757b0a 100644
--- a/Middlewares/ST/STM32_USB_Device_Library/Core/Src/usbd_core.c
+++ b/Middlewares/ST/STM32_USB_Device_Library/Core/Src/usbd_core.c
@@ -978,6 +978,11 @@ USBD_StatusTypeDef USBD_LL_IsoOUTIncomplete(USBD_HandleTypeDef *pdev,
   return USBD_OK;
 }
 
+#include "cmsis_os2.h"
+extern volatile uint32_t ulogUsbIsEstablished;
+extern osEventFlagsId_t ulogFlags;
+#define ULOG_DEV_CONNECTED_WAKEUP_FLAG 0x2
+
 /**
   * @brief  USBD_LL_DevConnected
   *         Handle device connection event
@@ -989,6 +994,9 @@ USBD_StatusTypeDef USBD_LL_DevConnected(USBD_HandleTypeDef *pdev)
   /* Prevent unused argument compilation warning */
   UNUSED(pdev);
 
+  ulogUsbIsEstablished = 1;
+  osEventFlagsSet(ulogFlags, ULOG_DEV_CONNECTED_WAKEUP_FLAG);
+
   return USBD_OK;
 }
 
@@ -1002,6 +1010,9 @@ USBD_StatusTypeDef USBD_LL_DevDisconnected(USBD_HandleTypeDef *pdev)
 {
   USBD_StatusTypeDef   ret = USBD_OK;
 
+  ulogUsbIsEstablished = 0;
+  osEventFlagsClear(ulogFlags, ULOG_DEV_CONNECTED_WAKEUP_FLAG);
+
   /* Free Class Resources */
   pdev->dev_state = USBD_STATE_DEFAULT;
 
diff --git a/USB_DEVICE/App/usbd_cdc_if.c b/USB_DEVICE/App/usbd_cdc_if.c
index dfb73d2..1a4653c 100644
--- a/USB_DEVICE/App/usbd_cdc_if.c
+++ b/USB_DEVICE/App/usbd_cdc_if.c
@@ -22,7 +22,7 @@
 #include "usbd_cdc_if.h"
 
 /* USER CODE BEGIN INCLUDE */
-
+#include "cmsis_os2.h"
 /* USER CODE END INCLUDE */
 
 /* Private typedef -----------------------------------------------------------*/
@@ -62,6 +62,7 @@
   */
 
 /* USER CODE BEGIN PRIVATE_DEFINES */
+#define ULOG_CDC_TRANSMIT_FINISH_FLAG 0x1
 /* USER CODE END PRIVATE_DEFINES */
 
 /**
@@ -109,7 +110,7 @@ uint8_t UserTxBufferFS[APP_TX_DATA_SIZE];
 extern USBD_HandleTypeDef hUsbDeviceFS;
 
 /* USER CODE BEGIN EXPORTED_VARIABLES */
-
+extern osEventFlagsId_t ulogFlags;
 /* USER CODE END EXPORTED_VARIABLES */
 
 /**
@@ -311,6 +312,8 @@ static int8_t CDC_TransmitCplt_FS(uint8_t *Buf, uint32_t *Len, uint8_t epnum)
   UNUSED(Buf);
   UNUSED(Len);
   UNUSED(epnum);
+
+  osEventFlagsSet(ulogFlags, ULOG_CDC_TRANSMIT_FINISH_FLAG);
   /* USER CODE END 13 */
   return result;
 }

From fb0fb6d9a8f77e6f560cbaa5559281d768801a1b Mon Sep 17 00:00:00 2001
From: hasslesstech <hasslesstech@tutanota.com>
Date: Mon, 12 Jan 2026 13:24:54 +0200
Subject: [PATCH 8/9] simplify logger connection recovery (name subject to
 change)

---
 KPI_Rover/Logger/ul_ulog.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/KPI_Rover/Logger/ul_ulog.c b/KPI_Rover/Logger/ul_ulog.c
index a78f898..dad1dd7 100644
--- a/KPI_Rover/Logger/ul_ulog.c
+++ b/KPI_Rover/Logger/ul_ulog.c
@@ -149,14 +149,9 @@ static void ulogTask(void *argument)
     {
       logMessage[MAX_LOG_MESSAGE_SIZE - 1] = '\0';
 
-      if (ulogUsbIsEstablished != 1)
+      while (ulogUsbIsEstablished != 1)
       {
-        while (ulogUsbIsEstablished != 1)
-        {
-          osEventFlagsWait(ulogFlags, ULOG_DEV_CONNECTED_WAKEUP_FLAG, 0, osWaitForever);
-          osDelay(50);
-        }
-
+        osEventFlagsWait(ulogFlags, ULOG_DEV_CONNECTED_WAKEUP_FLAG, 0, osWaitForever);
         osDelay(2000);
       }
 

From 55b1bd2d3ab65a2451eb88bb60cc4d70c8ab63f5 Mon Sep 17 00:00:00 2001
From: hasslesstech <hasslesstech@tutanota.com>
Date: Tue, 13 Jan 2026 00:28:42 +0200
Subject: [PATCH 9/9] fix ulog #3 (name subject to change)

---
 Core/Src/main.c                 |  2 +-
 KPI_Rover/Database/ulDatabase.h |  4 ++--
 KPI_Rover/KPIRover.c            | 11 +++++++++--
 KPI_Rover/Logger/ul_ulog.c      |  4 +---
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/Core/Src/main.c b/Core/Src/main.c
index 824509b..6f5df16 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -64,7 +64,7 @@ UART_HandleTypeDef huart3;
 osThreadId_t defaultTaskHandle;
 const osThreadAttr_t defaultTask_attributes = {
   .name = "defaultTask",
-  .stack_size = 128 * 4,
+  .stack_size = 512 * 4,
   .priority = (osPriority_t) osPriorityNormal,
 };
 /* USER CODE BEGIN PV */
diff --git a/KPI_Rover/Database/ulDatabase.h b/KPI_Rover/Database/ulDatabase.h
index b5d098d..ed44684 100644
--- a/KPI_Rover/Database/ulDatabase.h
+++ b/KPI_Rover/Database/ulDatabase.h
@@ -17,12 +17,12 @@ enum ulDatabase_ParamType {
 };
 
 enum ulDatabase_ParamId {
+	ENCODER_CONTROL_PERIOD_MS,
+	ENCODER_TICKS_PER_REVOLUTION,
 	MOTOR_FL_RPM,
 	MOTOR_FR_RPM,
 	MOTOR_RL_RPM,
 	MOTOR_RR_RPM,
-	ENCODER_CONTROL_PERIOD_MS,
-	ENCODER_TICKS_PER_REVOLUTION,
 	PARAM_COUNT
 };
 
diff --git a/KPI_Rover/KPIRover.c b/KPI_Rover/KPIRover.c
index d04d367..4b2eea6 100644
--- a/KPI_Rover/KPIRover.c
+++ b/KPI_Rover/KPIRover.c
@@ -2,18 +2,25 @@
 #include "cmsis_os.h"
 
 #include "Database/ulDatabase.h"
+#include "Database/ulStorage.h"
+#include "Encoders/ulEncoder.h"
 
+#include "ulog.h"
+#include "ul_ulog.h"
 
 static struct ulDatabase_ParamMetadata ulDatabase_params[] = {
+		{0, UINT16, true, 5}, // ENCODER_CONTROL_PERIOD_MS,
+		{0, FLOAT, true, 820.0f}, // ENCODER_TICKS_PER_REVOLUTION,
 		{0, INT32, false, 0}, // MOTOR_FL_RPM,
 		{0, INT32, false, 0}, // MOTOR_FR_RPM,
 		{0, INT32, false, 0}, // MOTOR_RL_RPM,
 		{0, INT32, false, 0}, // MOTOR_RR_RPM,
-		{0, UINT16, true, 5}, // ENCODER_CONTROL_PERIOD_MS,
-		{0, FLOAT, true, 820.0f} // ENCODER_TICKS_PER_REVOLUTION,
 };
 
 void KPIRover_Init(void) {
+	ULOG_INIT();
+	ULOG_SUBSCRIBE(ul_ulog_send, ULOG_DEBUG_LEVEL);
 	ulDatabase_init(ulDatabase_params, sizeof(ulDatabase_params) / sizeof(struct ulDatabase_ParamMetadata));
+	ulStorage_init();
 	ulEncoder_Init();
 }
diff --git a/KPI_Rover/Logger/ul_ulog.c b/KPI_Rover/Logger/ul_ulog.c
index dad1dd7..ae4c47d 100644
--- a/KPI_Rover/Logger/ul_ulog.c
+++ b/KPI_Rover/Logger/ul_ulog.c
@@ -75,6 +75,7 @@ void ul_ulog_init()
   }
 
   ulogFlags = osEventFlagsNew(NULL);
+  ulogUsbIsEstablished = 0;
 }
 
 void ul_ulog_send(ulog_level_t level, const char *filename, char *msg)
@@ -137,9 +138,6 @@ void ul_ulog_send(ulog_level_t level, const char *filename, char *msg)
 
 static void ulogTask(void *argument)
 {
-  ULOG_INIT();
-  ULOG_SUBSCRIBE(ul_ulog_send, ULOG_DEBUG_LEVEL);
-
   for (;;)
   {
     char logMessage[MAX_LOG_MESSAGE_SIZE];