esp32: Add VFS FAT partition to partitions.csv and mount it as the FS.

This patch uses the newly-added esp32.Partition class to replace the
existing FlashBdev class.  Partition objects implement the block protocol
so can be directly mounted via uos.mount().  This has the following
benefits:

- allows the filesystem partition location and size to be specified in
  partitions.csv, and overridden by a particular board
- very easily allows to have multiple filesystems by simply adding extra
  entries to partitions.csv
- improves efficiency/speed of filesystem operations because the block
  device is implemented fully in C
- opens the possibility to have encrypted flash storage (since Partitions
  can be encrypted)

Note that this patch is fully backwards compatible: existing filesystems
remain untouched and work with this new code.
This commit is contained in:
Damien George 2019-08-20 16:52:36 +10:00
parent f9d142523c
commit 31de44775c
2 changed files with 4 additions and 33 deletions

View File

@ -1,34 +1,4 @@
import esp
from esp32 import Partition
class FlashBdev:
SEC_SIZE = 4096
START_SEC = esp.flash_user_start() // SEC_SIZE
def __init__(self, blocks):
self.blocks = blocks
def readblocks(self, n, buf):
#print("readblocks(%s, %x(%d))" % (n, id(buf), len(buf)))
esp.flash_read((n + self.START_SEC) * self.SEC_SIZE, buf)
def writeblocks(self, n, buf):
#print("writeblocks(%s, %x(%d))" % (n, id(buf), len(buf)))
#assert len(buf) <= self.SEC_SIZE, len(buf)
esp.flash_erase(n + self.START_SEC)
esp.flash_write((n + self.START_SEC) * self.SEC_SIZE, buf)
def ioctl(self, op, arg):
#print("ioctl(%d, %r)" % (op, arg))
if op == 4: # BP_IOCTL_SEC_COUNT
return self.blocks
if op == 5: # BP_IOCTL_SEC_SIZE
return self.SEC_SIZE
size = esp.flash_size()
if size < 1024*1024:
# flash too small for a filesystem
bdev = None
else:
# for now we use a fixed size for the filesystem
bdev = FlashBdev(2048 * 1024 // FlashBdev.SEC_SIZE)
bdev = Partition.find(Partition.TYPE_DATA, label='vfs')
bdev = bdev[0] if bdev else None

View File

@ -3,3 +3,4 @@
nvs, data, nvs, 0x9000, 0x6000,
phy_init, data, phy, 0xf000, 0x1000,
factory, app, factory, 0x10000, 0x180000,
vfs, data, fat, 0x200000, 0x200000,

1 # Name, Type, SubType, Offset, Size, Flags
3 nvs, data, nvs, 0x9000, 0x6000,
4 phy_init, data, phy, 0xf000, 0x1000,
5 factory, app, factory, 0x10000, 0x180000,
6 vfs, data, fat, 0x200000, 0x200000,