| 243 | self.spi.write(b"\xff") |
| 244 | |
| 245 | def readblocks(self, block_num, buf): |
| 246 | # workaround for shared bus, required for (at least) some Kingston |
| 247 | # devices, ensure MOSI is high before starting transaction |
| 248 | self.spi.write(b"\xff") |
| 249 | |
| 250 | nblocks = len(buf) // 512 |
| 251 | assert nblocks and not len(buf) % 512, "Buffer length is invalid" |
| 252 | if nblocks == 1: |
| 253 | # CMD17: set read address for single block |
| 254 | if self.cmd(17, block_num * self.cdv, 0, release=False) != 0: |
| 255 | # release the card |
| 256 | self.cs(1) |
| 257 | raise OSError(5) # EIO |
| 258 | # receive the data and release card |
| 259 | self.readinto(buf) |
| 260 | else: |
| 261 | # CMD18: set read address for multiple blocks |
| 262 | if self.cmd(18, block_num * self.cdv, 0, release=False) != 0: |
| 263 | # release the card |
| 264 | self.cs(1) |
| 265 | raise OSError(5) # EIO |
| 266 | offset = 0 |
| 267 | mv = memoryview(buf) |
| 268 | while nblocks: |
| 269 | # receive the data and release card |
| 270 | self.readinto(mv[offset : offset + 512]) |
| 271 | offset += 512 |
| 272 | nblocks -= 1 |
| 273 | if self.cmd(12, 0, 0xFF, skip1=True): |
| 274 | raise OSError(5) # EIO |
| 275 | |
| 276 | def writeblocks(self, block_num, buf): |
| 277 | # workaround for shared bus, required for (at least) some Kingston |