Added missing copyright line to every license header.

Fixed a bug that was causing garbage volume labels when no volume label was specified.
Corrected details in the README and added a FAQ section.
Other small fixes and code cleanup.

Author: profi200

README.md

@@ -3,7 +3,7 @@ Unfortunately SDFormatter [was](https://www.sdcard.org/downloads/sd-memory-card-
 
 Multiple SD cards with different capacities have been tested and this tool formats them 1:1 the same as SDFormatter with the following exceptions:
 * SDFormatter does not set the jmp instruction offset in the boot sector for FAT12/16/32. sdFormatLinux does.
-* For exFAT sdFormatLinux clears unused FAT entries SDFormatter leaves untouched and SDFormatter clears more areas after root directory cluster. As far as i can tell these differences don't matter.
+* For exFAT sdFormatLinux clears the area between last FAT entry and cluster heap but SDFormatter doesn't. As far as i can tell this difference doesn't matter.
 * sdFormatLinux currently does not preserve OEM flash parameters when reformatting in exFAT. It will recalculate the correct values instead.
 
 ## Examples
@@ -13,6 +13,14 @@ Erase (TRIM) and format SD card (recommended). TRIM will not work with USB card
 Erase and format with label.  
 `sudo sdFormatLinux -l 'MY LABEL' -e trim /dev/mmcblkX`
 
+Erase and format a SDXC card to FAT32 (64 KiB clusters).  
+`sudo sdFormatLinux -e trim -f /dev/mmcblkX`
+
+## FAQ
+**Q: Why should i format my SDXC card with this tool to FAT32 instead of using guiformat/other tools?**\
+A: Because most of these tools are not designed for flash based media and will format them incorrectly causing lower lifespan and performance.  
+There is a common myth that you should only use 32 KB (actually KiB) clusters which is false. sdFormatLinux will use 64 KiB clusters when formatting SDXC cards to FAT32 and it works in every device compliant to Microsoft's FAT specification.
+
 ## Compiling
 Just run `make`. It automatically builds a hardened version.
 

include/blockdev.h

@@ -1,6 +1,7 @@
 #pragma once
 
 // SPDX-License-Identifier: MIT
+// Copyright (c) 2023 profi200
 
 #include "types.h"
 
@@ -61,7 +62,7 @@ class BlockDev
 	 *
 	 * @return     Returns 0 on success or errno.
 	 */
-	int read(u8 *buf, const u64 sector, const u64 count) const noexcept;
+	int read(void *buf, const u64 sector, const u64 count) const noexcept;
 
 	/**
 	 * @brief      Writes sectors to the block device.
@@ -72,7 +73,7 @@ class BlockDev
 	 *
 	 * @return     Returns 0 on success or errno.
 	 */
-	int write(const u8 *buf, const u64 sector, const u64 count) noexcept;
+	int write(const void *buf, const u64 sector, const u64 count) noexcept;
 
 	/**
 	 * @brief      Perform a TRIM/erase on the whole block device.

include/buffered_fs_writer.h

@@ -1,8 +1,8 @@
 #pragma once
 
 // SPDX-License-Identifier: MIT
+// Copyright (c) 2023 profi200
 
-#include <cstring>
 #include <memory>
 #include <stdexcept>
 #include "types.h"
@@ -84,7 +84,7 @@ class BufferedFsWriter final : private BlockDev
 	 *
 	 * @return     Returns 0 on success or errno.
 	 */
-	int write(const u8 *buf, const u64 size) noexcept;
+	int write(const void *buf, const u64 size) noexcept;
 
 	/**
 	 * @brief      Fills until offset and writes size bytes from buf.
@@ -95,7 +95,7 @@ class BufferedFsWriter final : private BlockDev
 	 *
 	 * @return     Returns 0 on success or errno.
 	 */
-	int fillAndWrite(const u8 *buf, const u64 offset, const u64 size) noexcept
+	int fillAndWrite(const void *buf, const u64 offset, const u64 size) noexcept
 	{
 		int res = fill(offset);
 		if(res == 0) res = write(buf, size);
@@ -111,7 +111,6 @@ class BufferedFsWriter final : private BlockDev
 	 */
 	int eraseAll(const bool secure = false) noexcept
 	{
-		//memset(m_buf.get(), 0, m_pos & m_blkMask);
 		m_pos = 0;
 		return BlockDev::eraseAll(secure);
 	}

include/errors.h

@@ -1,6 +1,7 @@
 #pragma once
 
 // SPDX-License-Identifier: MIT
+// Copyright (c) 2023 profi200
 
 
 enum

include/exfat.h

@@ -53,7 +53,7 @@ typedef struct
 } FlashParameters;
 static_assert(offsetof(FlashParameters, reserved) == 44, "Member reserved of FlashParameters not at offsetof 44.");
 
-typedef struct
+typedef struct alignas(u64) // ARM GCC generates terrible code without alignas(u64).
 {
 	u8 entryType;
 	union
@@ -76,10 +76,50 @@ typedef struct
 		struct __attribute__((packed))
 		{
 			u8  characterCount;
-			u16 volumeLabel[11];
+			char16_t volumeLabel[11];
 			u8  reserved[8];
 		} label;
-		// TODO: Other entry types.
+		struct __attribute__((packed))
+		{
+			u8  secondaryCount;
+			u16 setChecksum;
+			u16 fileAttributes;
+			u8  reserved1[2];
+			u32 createTimestamp;
+			u32 lastModifiedTimestamp;
+			u32 lastAccessedTimestamp;
+			u8  create10msIncrement;
+			u8  lastModified10msIncrement;
+			u8  createUtcOffset;
+			u8  lastModifiedUtcOffset;
+			u8  lastAccessedUtcOffset;
+			u8  reserved2[7];
+		} file; // And directory.
+		struct __attribute__((packed))
+		{
+			u8  secondaryCount;
+			u16 setChecksum;
+			u16 generalPrimaryFlags;
+			u8  volumeGuid[16];
+			u8  reserved[10];
+		} guid;
+		struct __attribute__((packed))
+		{
+			u8  generalSecondaryFlags;
+			u8  reserved1;
+			u8  nameLength;
+			u16 nameHash;
+			u8  reserved2[2];
+			u64 validDataLength;
+			u8  reserved3[4];
+			u32 firstCluster;
+			u64 dataLength;
+		} stream;
+		struct __attribute__((packed))
+		{
+			u8  generalSecondaryFlags;
+			char16_t fileName[15];
+		} name;
 	};
 } ExfatDirEnt;
 static_assert(sizeof(ExfatDirEnt) == 32, "ExfatDirEnt is not 32 bytes.");

include/exfat_up_case_table.h

@@ -1,13 +1,14 @@
 #pragma once
 
 // SPDX-License-Identifier: MIT
+// Copyright (c) 2023 profi200
 
 #include "types.h"
 
 #define UP_CASE_TABLE_CHECKSUM  (0xE619D30Du)
 
 
-static const u16 upCaseTable[2918] =
+static const char16_t g_upCaseTable[2918] =
 {
 	0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000A, 0x000B,
 	0x000C, 0x000D, 0x000E, 0x000F, 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,

include/fat.h

@@ -1,6 +1,7 @@
 #pragma once
 
 // SPDX-License-Identifier: MIT
+// Copyright (c) 2023 profi200
 
 #include <cstddef>
 #include "types.h"
@@ -14,17 +15,17 @@
 // Boot sector.
 typedef struct __attribute__((packed))
 {
-	u8 jmpBoot[3];   // {0xEB, 0xXX, 0x90} or {0xE9, 0xXX, 0xXX}.
+	u8  jmpBoot[3];  // {0xEB, 0xXX, 0x90} or {0xE9, 0xXX, 0xXX}.
 	char oemName[8]; // Usually system name that formatted the volume.
 
 	// BIOS Parameter Block.
 	u16 bytesPerSec; // 512, 1024, 2048 or 4096. Usually 512.
-	u8 secPerClus;   // 1, 2, 4, 8, 16, 32, 64 or 128.
+	u8  secPerClus;  // 1, 2, 4, 8, 16, 32, 64 or 128.
 	u16 rsvdSecCnt;  // Must not be 0.
-	u8 numFats;      // Should be 2. 1 is also allowed.
+	u8  numFats;     // Should be 2. 1 is also allowed.
 	u16 rootEntCnt;  // 0 for FAT32.
 	u16 totSec16;    // Must be zero for FAT32.
-	u8 media;        // 0xF0, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE or 0xFF. Usually 0xF8.
+	u8  media;       // 0xF0, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE or 0xFF. Usually 0xF8.
 	u16 fatSz16;     // Must be zero for FAT32.
 	u16 secPerTrk;
 	u16 numHeads;
@@ -36,13 +37,13 @@ typedef struct __attribute__((packed))
 	{
 		struct __attribute__((packed)) // FAT12/FAT16.
 		{
-			u8 drvNum;          // 0x80 or 0x00.
-			u8 reserved1;       // Must be 0. Used by Windows for dirty flag (bit 0 set = dirty).
-			u8 bootSig;         // 0x29 if one or both of the following 2 fields are non-zero.
+			u8  drvNum;         // 0x80 or 0x00.
+			u8  reserved1;      // Must be 0. Used by Windows for dirty flag (bit 0 set = dirty).
+			u8  bootSig;        // 0x29 if one or both of the following 2 fields are non-zero.
 			u32 volId;          // Volume serial number generated from date and time.
 			char volLab[11];    // "NO NAME    " or space padded label.
 			char filSysType[8]; // "FAT12   ", "FAT16   " or "FAT     ".
-			u8 bootCode[448];
+			u8  bootCode[448];
 		} ebpb;
 		struct __attribute__((packed)) // FAT32.
 		{
@@ -52,14 +53,14 @@ typedef struct __attribute__((packed))
 			u32 rootClus;       // Should be 2 or the first non-defective cluster.
 			u16 fsInfoSector;   // Usually 1.
 			u16 bkBootSec;      // 0 or 6. Backup boot sector must be present if the later.
-			u8 reserved[12];    // Must be 0.
-			u8 drvNum;          // 0x80 or 0x00.
-			u8 reserved1;       // Must be 0. Used by Windows for dirty flag (bit 0 set = dirty).
-			u8 bootSig;         // 0x29 if one or both of the following 2 fields are non-zero.
+			u8  reserved[12];   // Must be 0.
+			u8  drvNum;         // 0x80 or 0x00.
+			u8  reserved1;      // Must be 0. Used by Windows for dirty flag (bit 0 set = dirty).
+			u8  bootSig;        // 0x29 if one or both of the following 2 fields are non-zero.
 			u32 volId;          // Volume serial number generated from date and time.
 			char volLab[11];    // "NO NAME    " or space padded label.
 			char filSysType[8]; // "FAT32   ".
-			u8 bootCode[420];
+			u8  bootCode[420];
 		} ebpb32;
 	};
 	u16 sigWord; // 0xAA55.
@@ -70,43 +71,43 @@ static_assert(offsetof(BootSec, sigWord) == 510, "Member sigWord of BootSec not
 
 typedef struct
 {
-	u32 leadSig;       // Must be 0x41615252.
-	u8 reserved1[480]; // Must be 0.
-	u32 strucSig;      // Must be 0x61417272.
-	u32 freeCount;     // Number of free clusters or 0xFFFFFFFF if unknown.
-	u32 nxtFree;       // First free cluster number or 0xFFFFFFFF if unknown.
-	u8 reserved2[12];  // Must be 0.
-	u32 trailSig;      // Must be 0xAA550000.
+	u32 leadSig;        // Must be 0x41615252.
+	u8  reserved1[480]; // Must be 0.
+	u32 strucSig;       // Must be 0x61417272.
+	u32 freeCount;      // Number of free clusters or 0xFFFFFFFF if unknown.
+	u32 nxtFree;        // First free cluster number or 0xFFFFFFFF if unknown.
+	u8  reserved2[12];  // Must be 0.
+	u32 trailSig;       // Must be 0xAA550000.
 } FsInfo;
 static_assert(offsetof(FsInfo, trailSig) == 508, "Member trailSig of FsInfo not at offset 508.");
 
 typedef struct
 {
-	char name[11];   // Short file name in 8:3 format. Maximum 11 characters.
-	u8 attr;         // Attribute bitmask. ATTR_READ_ONLY 0x01, ATTR_HIDDEN 0x02, ATTR_SYSTEM 0x04, ATTR_VOLUME_ID 0x08, ATTR_DIRECTORY 0x10, ATTR_ARCHIVE 0x20.
-	u8 ntRes;        // Must be 0.
-	u8 crtTimeTenth; // Creation time tenths of a second.
-	u16 crtTime;     // Creation time in 2 second units.
-	u16 crtDate;     // Creation date.
-	u16 lstAccDate;  // Last access date. Updated on write.
-	u16 fstClusHi;   // High u16 of first data cluster. Must be 0 for FAT12/16.
-	u16 wrtTime;     // Last (modification) write time.
-	u16 wrtDate;     // Last (modification) write date.
-	u16 fstClusLo;   // Low u16 of first data cluster.
-	u32 fileSize;    // File/directory size in bytes.
+	char name[11];    // Short file name in 8:3 format. Maximum 11 characters.
+	u8  attr;         // Attribute bitmask. ATTR_READ_ONLY 0x01, ATTR_HIDDEN 0x02, ATTR_SYSTEM 0x04, ATTR_VOLUME_ID 0x08, ATTR_DIRECTORY 0x10, ATTR_ARCHIVE 0x20.
+	u8  ntRes;        // Must be 0.
+	u8  crtTimeTenth; // Creation time tenths of a second.
+	u16 crtTime;      // Creation time in 2 second units.
+	u16 crtDate;      // Creation date.
+	u16 lstAccDate;   // Last access date. Updated on write.
+	u16 fstClusHi;    // High u16 of first data cluster. Must be 0 for FAT12/16.
+	u16 wrtTime;      // Last (modification) write time.
+	u16 wrtDate;      // Last (modification) write date.
+	u16 fstClusLo;    // Low u16 of first data cluster.
+	u32 fileSize;     // File/directory size in bytes.
 } FatDirEnt;
 static_assert(offsetof(FatDirEnt, fileSize) == 28, "Member fileSize of FatDirEnt not at offset 28.");
 
 typedef struct __attribute__((packed))
 {
-	u8 ord;        // Order of LDIR entries. Last entry (which comes first) must have LAST_LONG_ENTRY (0x40) set.
-	u16 name1[5];  // UTF-16 character 1-5 of long name.
-	u8 attr;       // Must be ATTR_LONG_NAME (DIR_ATTR_VOLUME_ID | DIR_ATTR_SYSTEM | DIR_ATTR_HIDDEN | DIR_ATTR_READ_ONLY).
-	u8 type;       // Must be 0 (sub-component of long name). Other values unknown (extensions).
-	u8 chksum;     // Checksum of 11 characters short name.
-	u16 name2[6];  // UTF-16 character 6-11 of long name.
-	u16 fstClusLo; // Must be 0.
-	u16 name3[2];  // UTF-16 character 12-13 of long name.
+	u8  ord;           // Order of LDIR entries. Last entry (which comes first) must have LAST_LONG_ENTRY (0x40) set.
+	char16_t name1[5]; // UTF-16 character 1-5 of long name.
+	u8  attr;          // Must be ATTR_LONG_NAME (DIR_ATTR_VOLUME_ID | DIR_ATTR_SYSTEM | DIR_ATTR_HIDDEN | DIR_ATTR_READ_ONLY).
+	u8  type;          // Must be 0 (sub-component of long name). Other values unknown (extensions).
+	u8  chksum;        // Checksum of 11 characters short name.
+	char16_t name2[6]; // UTF-16 character 6-11 of long name.
+	u16 fstClusLo;     // Must be 0.
+	char16_t name3[2]; // UTF-16 character 12-13 of long name.
 } FatLdirEnt;
 static_assert(offsetof(FatLdirEnt, name3) == 28, "Member name3 of FatLdirEnt not at offset 28.");
 

include/format.h

@@ -1,6 +1,7 @@
 #pragma once
 
 // SPDX-License-Identifier: MIT
+// Copyright (c) 2023 profi200
 
 #include <string>
 #include "types.h"

include/mbr.h

@@ -1,6 +1,7 @@
 #pragma once
 
 // SPDX-License-Identifier: MIT
+// Copyright (c) 2023 profi200
 
 #include <cstddef>
 #include "types.h"
@@ -10,7 +11,7 @@
 
 typedef struct
 {
-	u8 status; // 0x80 active/bootable, 0x00 inactive.
+	u8 status;      // 0x80 active/bootable, 0x00 inactive.
 	u8 startCHS[3];
 	u8 type;
 	u8 endCHS[3];
@@ -23,7 +24,7 @@ typedef struct
 {
 	u8 bootstrap[440];
 	u32 diskSig;
-	u16 reserved; // 0x0000. 0x5A5A for copy protected.
+	u16 reserved;           // 0x0000. 0x5A5A for copy protected.
 	PartEntry partTable[4];
 	u16 bootSig;
 } __attribute__((packed)) Mbr;

include/privileges.h

@@ -1,6 +1,7 @@
 #pragma once
 
 // SPDX-License-Identifier: MIT
+// Copyright (c) 2023 profi200