feat(core/sdbackup): allow partitioning

- configure FatFS library for f_fdisk
- mkfs call now also creates the partition based on the intended use of
  the card
- WIP

core/embed/extmod/modtrezorio/ff.c

@@ -241,8 +241,8 @@
 
 
 /* Definitions of logical drive - physical location conversion */
-#define LD2PD(vol) (BYTE)(vol)	/* Each logical drive is associated with the same physical drive number */
-#define LD2PT(vol) 0			/* Auto partition search */
+#define LD2PD(vol) VolToPart[vol].pd	/* Get physical drive number */
+#define LD2PT(vol) VolToPart[vol].pt	/* Get partition number (0:auto search, 1..:forced partition number) */
 
 
 /* Definitions of sector size */
@@ -2967,7 +2967,7 @@ FRESULT f_mkdir (
 	FATFS *fs = NULL;
 	DIR dj = {0};
 	FFOBJID sobj = {0};
-  DWORD dcl = 0, pcl = 0, tm = 0;
+    DWORD dcl = 0, pcl = 0, tm = 0;
 	DEF_NAMBUF
 
 
@@ -3638,6 +3638,33 @@ FRESULT f_mkfs (
 
 
 
+/*-----------------------------------------------------------------------*/
+/* Create Partition Table on the Physical Drive                          */
+/*-----------------------------------------------------------------------*/
+
+FRESULT f_fdisk (
+	BYTE pdrv,			/* Physical drive number */
+	const LBA_t ptbl[],	/* Pointer to the size table for each partitions */
+	void* work			/* Pointer to the working buffer (null: use heap memory) */
+)
+{
+	BYTE *buf = (BYTE*)work;
+	DSTATUS stat = 0;
+	FRESULT res = 0;
+
+
+	/* Initialize the physical drive */
+	stat = disk_initialize(pdrv);
+	if (stat & STA_NOINIT) return FR_NOT_READY;
+	if (stat & STA_PROTECT) return FR_WRITE_PROTECTED;
+
+	if (!buf) return FR_NOT_ENOUGH_CORE;
+
+	res = create_partition(pdrv, ptbl, 0x07, buf);	/* Create partitions (system ID is temporary setting and determined by f_mkfs) */
+
+	LEAVE_MKFS(res);
+}
+
 #endif /* !FF_FS_READONLY && FF_USE_MKFS */
 
 

core/embed/extmod/modtrezorio/ff.h

@@ -118,7 +118,7 @@ typedef struct {
 	BYTE pd;	/* Physical drive number */
 	BYTE pt;	/* Partition: 0:Auto detect, 1-4:Forced partition) */
 } PARTITION;
-extern PARTITION VolToPart[];	/* Volume - Partition mapping table */
+extern const PARTITION VolToPart[];	/* Volume - Partition mapping table */
 #endif
 
 #if FF_STR_VOLUME_ID

core/embed/extmod/modtrezorio/ff_unifdef.sh

@@ -15,7 +15,7 @@ unifdef \
     -DFF_FS_RPATH=0 \
     -DFF_VOLUMES=1 \
     -DFF_STR_VOLUME_ID=0 \
-    -DFF_MULTI_PARTITION=0 \
+    -DFF_MULTI_PARTITION=1 \
     -DFF_USE_TRIM=0 \
     -DFF_FS_NOFSINFO=0 \
     -DFF_FS_TINY=0 \
@@ -24,7 +24,6 @@ unifdef \
     -DFF_FS_LOCK=0 \
     -DFF_FS_REENTRANT=0 \
     -DFF_LBA64=0 \
-    -DFF_MULTI_PARTITION=0 \
     ff.c -o ff.c
 
 unifdef \

core/embed/extmod/modtrezorio/ffconf.h

@@ -186,7 +186,7 @@
 */
 
 
-#define FF_MULTI_PARTITION	0
+#define FF_MULTI_PARTITION	1
 /* This option switches support for multiple volumes on the physical drive.
 /  By default (0), each logical drive number is bound to the same physical drive
 /  number and only an FAT volume found on the physical drive will be mounted.

core/embed/extmod/modtrezorio/modtrezorio-fatfs.h

@@ -87,6 +87,27 @@ MP_DEFINE_EXCEPTION(NoFilesystem, FatFSError)
     }                                        \
   }
 
+// Define and initialize the VolToPart array
+// For more info, see: http://elm-chan.org/fsw/ff/doc/filename.html#vol
+// Assumption: Trezor always operate with only one Volume
+const PARTITION VolToPart[] = {
+    {0, 1}  // Logical Volume 0 => Physical Disk 0, Partition 1
+};
+
+// Helper function to create a partition spanned over a portition (in
+// percentage) of the card.
+void make_partition(int disk_portion_p100) {
+  if ((disk_portion_p100 <= 0) || (disk_portion_p100 > 100)) {
+    FATFS_RAISE(FatFSError, FR_MKFS_ABORTED);
+  }
+  uint8_t working_buf[FF_MAX_SS] = {0};
+  LBA_t plist[] = {disk_portion_p100, 0};
+  FRESULT res = f_fdisk(0, plist, working_buf);
+  if (res != FR_OK) {
+    FATFS_RAISE(FatFSError, res);
+  }
+}
+
 DSTATUS disk_initialize(BYTE pdrv) { return disk_status(pdrv); }
 
 DSTATUS disk_status(BYTE pdrv) {
@@ -528,24 +549,38 @@ STATIC mp_obj_t mod_trezorio_fatfs_is_mounted() {
 STATIC MP_DEFINE_CONST_FUN_OBJ_0(mod_trezorio_fatfs_is_mounted_obj,
                                  mod_trezorio_fatfs_is_mounted);
 
-/// def mkfs() -> None:
+/// def mkfs(for_sd_backup: bool=False) -> None:
 ///     """
-///     Create a FAT volume on the SD card,
+///     Create a FAT volume on the SD card.
+///     If for_sd_backup is True, the volume consumes only a portion of the
+///     card. Otherwise, the volume is created over the whole card.
 ///     """
-STATIC mp_obj_t mod_trezorio_fatfs_mkfs() {
+STATIC mp_obj_t mod_trezorio_fatfs_mkfs(size_t n_args, const mp_obj_t *args) {
   if (_fatfs_instance_is_mounted()) {
     FATFS_RAISE(FatFSError, FR_LOCKED);
   }
+
+  // create partition
+  if (n_args > 0 && args[0] == mp_const_true) {
+    // for SD card backup: we need small partition and keep the rest unallocated
+    make_partition(60);  // TODO decide on the exact portion
+  } else {
+    // for other use (SD salt): make the partitio over the whole space.
+    make_partition(100);
+  }
+
+  // create FAT volume mapped to the created partition
   MKFS_PARM params = {FM_FAT32, 0, 0, 0, 0};
   uint8_t working_buf[FF_MAX_SS] = {0};
   FRESULT res = f_mkfs("", &params, working_buf, sizeof(working_buf));
   if (res != FR_OK) {
     FATFS_RAISE(FatFSError, res);
   }
+
   return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(mod_trezorio_fatfs_mkfs_obj,
-                                 mod_trezorio_fatfs_mkfs);
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_trezorio_fatfs_mkfs_obj, 0, 1,
+                                           mod_trezorio_fatfs_mkfs);
 
 /// def setlabel(label: str) -> None:
 ///     """

core/embed/extmod/modtrezorio/modtrezorio-sdcard.h

@@ -78,7 +78,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_0(mod_trezorio_sdcard_capacity_obj,
 ///     """
 ///     Reads blocks starting with block_num from the SD card into buf.
 ///     Number of bytes read is length of buf rounded down to multiply of
-///     SDCARD_BLOCK_SIZE. Returns True if in case of success, False otherwise.
+///     SDCARD_BLOCK_SIZE. 
 ///     """
 STATIC mp_obj_t mod_trezorio_sdcard_read(mp_obj_t block_num, mp_obj_t buf) {
   uint32_t block = trezor_obj_get_uint(block_num);
@@ -97,7 +97,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_trezorio_sdcard_read_obj,
 ///     """
 ///     Writes blocks starting with block_num from buf to the SD card.
 ///     Number of bytes written is length of buf rounded down to multiply of
-///     SDCARD_BLOCK_SIZE. Returns True if in case of success, False otherwise.
+///     SDCARD_BLOCK_SIZE. 
 ///     """
 STATIC mp_obj_t mod_trezorio_sdcard_write(mp_obj_t block_num, mp_obj_t buf) {
   uint32_t block = trezor_obj_get_uint(block_num);

core/mocks/generated/trezorio/fatfs.pyi

@@ -166,9 +166,11 @@ def is_mounted() -> bool:
 
 
 # extmod/modtrezorio/modtrezorio-fatfs.h
-def mkfs() -> None:
+def mkfs(for_sd_backup: bool=False) -> None:
     """
-    Create a FAT volume on the SD card,
+    Create a FAT volume on the SD card.
+    If for_sd_backup is True, the volume consumes only a portion of the
+    card. Otherwise, the volume is created over the whole card.
     """
 
 

core/mocks/generated/trezorio/sdcard.pyi

@@ -37,7 +37,7 @@ def read(block_num: int, buf: bytearray) -> None:
     """
     Reads blocks starting with block_num from the SD card into buf.
     Number of bytes read is length of buf rounded down to multiply of
-    SDCARD_BLOCK_SIZE. Returns True if in case of success, False otherwise.
+    SDCARD_BLOCK_SIZE. 
     """
 
 
@@ -46,5 +46,5 @@ def write(block_num: int, buf: bytes) -> None:
     """
     Writes blocks starting with block_num from buf to the SD card.
     Number of bytes written is length of buf rounded down to multiply of
-    SDCARD_BLOCK_SIZE. Returns True if in case of success, False otherwise.
+    SDCARD_BLOCK_SIZE. 
     """