1 files changed, 35 insertions, 0 deletions
diff --git a/ports/esp8266/modules/flashbdev.py b/ports/esp8266/modules/flashbdev.py
new file mode 100644
index 000000000..40ba655c6
--- /dev/null
+++ b/ports/esp8266/modules/flashbdev.py
@@ -0,0 +1,35 @@
+import esp
+
+class FlashBdev:
+
+    SEC_SIZE = 4096
+    RESERVED_SECS = 1
+    START_SEC = esp.flash_user_start() // SEC_SIZE + RESERVED_SECS
+    NUM_BLK = 0x6b - RESERVED_SECS
+
+    def __init__(self, blocks=NUM_BLK):
+        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:
+    bdev = None
+else:
+    # 20K at the flash end is reserved for SDK params storage
+    bdev = FlashBdev((size - 20480) // FlashBdev.SEC_SIZE - FlashBdev.START_SEC)