[stm32] H7 flash driver and example

README.md

@@ -466,7 +466,7 @@ Please [discover modm's peripheral drivers for your specific device][discover].
 <td align="center">✅</td>
 <td align="center">✅</td>
 <td align="center">○</td>
-<td align="center">○</td>
+<td align="center">✅</td>
 <td align="center">○</td>
 <td align="center">○</td>
 <td align="center">○</td>

examples/nucleo_h723zg/flash/main.cpp

@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2026, Henrik Hose
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <cstring>
+#include <modm/board.hpp>
+
+#undef MODM_LOG_LEVEL
+#define MODM_LOG_LEVEL modm::log::INFO
+
+extern "C" const uint32_t __flash_reserved_start[];
+
+static Flash::MaxWordType
+makeFlashWord(const uint32_t *data)
+{
+	Flash::MaxWordType word;
+	for (size_t ii = 0; ii < Flash::FlashWordWords; ++ii) {
+		word.data[ii] = data[ii];
+	}
+	return word;
+}
+
+int
+main()
+{
+	Board::initialize();
+
+	MODM_LOG_INFO << "STM32H7 Flash write/read example" << modm::endl;
+
+	constexpr uint32_t dummy_data[] = {
+		0xDEADBEEF, 0xCAFEBABE, 0x12345678, 0xAABBCCDD,
+		0x11223344, 0x55667788, 0x99AABBCC, 0xDDEEFF00,
+		0x0BADCAFE, 0xC001D00D, 0xFEEDFACE, 0x8BADF00D,
+		0x13579BDF, 0x2468ACE0, 0x10203040, 0x50607080,
+	};
+	constexpr size_t num_values = std::size(dummy_data);
+	static_assert(num_values % Flash::FlashWordWords == 0);
+	constexpr size_t num_flash_words = num_values / Flash::FlashWordWords;
+
+	const uintptr_t base = reinterpret_cast<uintptr_t>(__flash_reserved_start);
+	const uint8_t sector = Flash::getPage(base - Flash::OriginAddr);
+
+	MODM_LOG_INFO << "Reserved sector: " << sector << "  base: 0x" << modm::hex << base
+				  << modm::endl;
+
+	if (not Flash::unlock())
+	{
+		MODM_LOG_ERROR << "Flash unlock failed!" << modm::endl;
+		while (1);
+	}
+
+	// Erase the reserved sector before writing
+	if (const uint32_t err = Flash::erase(sector); err != 0)
+	{
+		MODM_LOG_ERROR << "Erase error: 0x" << modm::hex << err << modm::endl;
+		while (1);
+	}
+	MODM_LOG_INFO << "Sector erased." << modm::endl;
+
+	// Write dummy data
+	uint32_t err{0};
+	for (size_t i = 0; i < num_flash_words; i++)
+		err |= Flash::program(base + i * Flash::FlashWordSize,
+							  makeFlashWord(&dummy_data[i * Flash::FlashWordWords]));
+
+	if (err != 0)
+	{
+		MODM_LOG_ERROR << "Program error: 0x" << modm::hex << err << modm::endl;
+		while (1);
+	}
+	MODM_LOG_INFO << "Write complete. Verifying..." << modm::endl;
+
+	// Read back and verify
+	for (size_t i = 0; i < num_values; i++)
+	{
+		uint32_t readback;
+		memcpy(&readback, reinterpret_cast<const void *>(base + i * sizeof(uint32_t)),
+			   sizeof(uint32_t));
+		const bool ok = (readback == dummy_data[i]);
+		MODM_LOG_INFO << "[" << i << "] wrote 0x" << modm::hex << dummy_data[i] << "  read 0x"
+					  << readback << (ok ? "  OK" : "  MISMATCH") << modm::endl;
+	}
+
+	while (1);
+	return 0;
+}

examples/nucleo_h723zg/flash/project.xml

@@ -0,0 +1,11 @@
+<library>
+  <extends>modm:nucleo-h723zg</extends>
+  <options>
+    <option name="modm:build:build.path">../../../build/nucleo_h723zg/flash</option>
+    <option name="modm:platform:cortex-m:linkerscript.flash_reserved">1024*128</option>
+  </options>
+  <modules>
+    <module>modm:platform:flash</module>
+    <module>modm:build:scons</module>
+  </modules>
+</library>

examples/nucleo_h743zi/flash/main.cpp

@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2026, Henrik Hose
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <cstring>
+#include <modm/board.hpp>
+
+#undef MODM_LOG_LEVEL
+#define MODM_LOG_LEVEL modm::log::INFO
+
+extern "C" const uint32_t __flash_reserved_start[];
+
+static Flash::MaxWordType
+makeFlashWord(const uint32_t *data)
+{
+	Flash::MaxWordType word;
+	for (size_t ii = 0; ii < Flash::FlashWordWords; ++ii) {
+		word.data[ii] = data[ii];
+	}
+	return word;
+}
+
+int
+main()
+{
+	Board::initialize();
+
+	MODM_LOG_INFO << "STM32H7 Flash write/read example" << modm::endl;
+
+	constexpr uint32_t dummy_data[] = {
+		0xDEADBEEF, 0xCAFEBABE, 0x12345678, 0xAABBCCDD,
+		0x11223344, 0x55667788, 0x99AABBCC, 0xDDEEFF00,
+		0x0BADCAFE, 0xC001D00D, 0xFEEDFACE, 0x8BADF00D,
+		0x13579BDF, 0x2468ACE0, 0x10203040, 0x50607080,
+	};
+	constexpr size_t num_values = std::size(dummy_data);
+	static_assert(num_values % Flash::FlashWordWords == 0);
+	constexpr size_t num_flash_words = num_values / Flash::FlashWordWords;
+
+	const uintptr_t base = reinterpret_cast<uintptr_t>(__flash_reserved_start);
+	const uint8_t sector = Flash::getPage(base - Flash::OriginAddr);
+
+	MODM_LOG_INFO << "Reserved sector: " << sector << "  base: 0x" << modm::hex << base
+				  << modm::endl;
+
+	if (not Flash::unlock())
+	{
+		MODM_LOG_ERROR << "Flash unlock failed!" << modm::endl;
+		while (1);
+	}
+
+	// Erase the reserved sector before writing
+	if (const uint32_t err = Flash::erase(sector); err != 0)
+	{
+		MODM_LOG_ERROR << "Erase error: 0x" << modm::hex << err << modm::endl;
+		while (1);
+	}
+	MODM_LOG_INFO << "Sector erased." << modm::endl;
+
+	// Write dummy data
+	uint32_t err{0};
+	for (size_t i = 0; i < num_flash_words; i++)
+		err |= Flash::program(base + i * Flash::FlashWordSize,
+							  makeFlashWord(&dummy_data[i * Flash::FlashWordWords]));
+
+	if (err != 0)
+	{
+		MODM_LOG_ERROR << "Program error: 0x" << modm::hex << err << modm::endl;
+		while (1);
+	}
+	MODM_LOG_INFO << "Write complete. Verifying..." << modm::endl;
+
+	// Read back and verify
+	for (size_t i = 0; i < num_values; i++)
+	{
+		uint32_t readback;
+		memcpy(&readback, reinterpret_cast<const void *>(base + i * sizeof(uint32_t)),
+			   sizeof(uint32_t));
+		const bool ok = (readback == dummy_data[i]);
+		MODM_LOG_INFO << "[" << i << "] wrote 0x" << modm::hex << dummy_data[i] << "  read 0x"
+					  << readback << (ok ? "  OK" : "  MISMATCH") << modm::endl;
+	}
+
+	while (1);
+	return 0;
+}

examples/nucleo_h743zi/flash/project.xml

@@ -0,0 +1,11 @@
+<library>
+  <extends>modm:nucleo-h743zi</extends>
+  <options>
+    <option name="modm:build:build.path">../../../build/nucleo_h743zi/flash</option>
+    <option name="modm:platform:cortex-m:linkerscript.flash_reserved">1024*128</option>
+  </options>
+  <modules>
+    <module>modm:platform:flash</module>
+    <module>modm:build:scons</module>
+  </modules>
+</library>

src/modm/platform/core/cortex/module.lb

@@ -87,27 +87,28 @@ def common_memories(env):
     memories = listify(device.get_driver("core")["memory"])
 
     # Convert from string to int and add offsets
-    flash_size = env.get(":platform:core:boot2_size", 0)
-    if flash_size:
+    if (flash_size := env.get(":platform:core:boot2_size", 0)):
         memories.append({
             "name": "flash",
             "access": "rx",
             "start": "0x10000000",
             "size": hex(flash_size)})
-    flash_offset = env.get(":platform:cortex-m:linkerscript.flash_offset", 0)
-    flash_reserved = env.get(":platform:cortex-m:linkerscript.flash_reserved", 0)
+    # sort by start address, so that we can find the "first" memory sections with a single pass
     for m in memories:
-        if m["name"] in ["flash", "flash1"]:
-            m["start"] = int(m["start"], 0) + flash_offset
-            m["size"] = int(m["size"], 0) - flash_offset
-        elif m["name"] in ["flash2", "flash"]:
-            m["start"] = int(m["start"], 0)
-            m["size"] = int(m["size"], 0) - flash_reserved
-        else:
-            m["start"] = int(m["start"], 0)
-            m["size"] = int(m["size"], 0)
-
+        m["start"] = int(m["start"], 0)
+        m["size"] = int(m["size"], 0)
     memories.sort(key=lambda m: m["start"])
+    physical_memories = list(m for m in memories if "alias" not in m)
+    # Flash offset is counted from the start of flash, which could be flash or flash1
+    if (flash_offset := env.get(":platform:cortex-m:linkerscript.flash_offset", 0)):
+        offset_flash = next(m for name in ["flash", "flash1", "flash2"] for m in memories if m["name"] == name)
+        offset_flash["start"] = offset_flash["start"] + flash_offset
+        offset_flash["size"] = offset_flash["size"] - flash_offset
+    # Reserved flash is counted from the end of flash, which could be flash2, flash1 or flash
+    if (flash_reserved := env.get(":platform:cortex-m:linkerscript.flash_reserved", 0)):
+        reserved_flash = next(m for name in ["flash2", "flash1", "flash"] for m in memories if m["name"] == name)
+        reserved_flash["size"] = reserved_flash["size"] - flash_reserved
+
     # Find all continuous memory sections
     cont = []
     index = 0
@@ -138,12 +139,13 @@ def common_memories(env):
         memories.append({
             "name": "flash_reserved",
             "access": "rx",
-            "start": next(m["start"] + m["size"] for m in memories if m["name"] in ["flash2", "flash1", "flash"]),
+            "start": reserved_flash["start"] + reserved_flash["size"],
             "size": flash_reserved})
         memories.sort(key=lambda m: m["start"])
 
     properties = {
         "memories": memories,
+        "physical_memories": physical_memories,
         "regions": [m["name"] for m in memories],
         "ram_regions": ram_regions,
         "cont_flash_regions": cont_flash_regions,