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Fix flash read #72

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Fix flash read #72

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6fde4bc
[ln882h] improve flash read speed by changing baudrate
lamauny Oct 12, 2025
9f018dc
[ln882h] fix UART number in help tip
lamauny Oct 12, 2025
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7 changes: 4 additions & 3 deletions ltchiptool/soc/ln882h/flash.py
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Original file line number Diff line number Diff line change
Expand Up @@ -11,11 +11,12 @@
from .util.ln882htool import LN882hTool

LN882H_GUIDE = [
"Connect UART1 of the LN882h to the USB-TTL adapter:",
"Connect UART0 of the LN882h to the USB-TTL adapter:",
[
("PC", "LN882h"),
("RX", "TX1 (GPIOA2 / P2)"),
("TX", "RX1 (GPIOA3 / P3)"),
("RX", "TX0 (GPIOA2 / P2)"),
("TX", "RX0 (GPIOA3 / P3)"),
("GND", "BOOT (GPIOA9 / P9)"),
("", ""),
("GND", "GND"),
],
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11 changes: 11 additions & 0 deletions ltchiptool/soc/ln882h/util/ln882htool.py
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Original file line number Diff line number Diff line change
Expand Up @@ -169,6 +169,7 @@ def flash_read(
chunk_size: int = 256, # maximum supported chunk size
) -> Generator[bytes, None, None]:
self.link()
prev_baudrate = self.s.baudrate
if not self.ramcode:
self.ram_boot()

Expand All @@ -177,6 +178,10 @@ def flash_read(
f"Chunk size {chunk_size} exceeds the maximum allowed (256)"
)

self.change_baudrate(LN882H_YM_BAUDRATE)
self.link()
self.push_timeout(0.02)

for start in range(offset, offset + length, chunk_size):
count = min(start + chunk_size, offset + length) - start
debug(f"Dumping bytes: start=0x{start:X}, count=0x{count:X}")
Expand All @@ -186,10 +191,16 @@ def flash_read(

valid, data = self.ym._verify_recv_checksum(True, data)
if verify and not valid:
self.change_baudrate(prev_baudrate)
self.pop_timeout()
raise RuntimeError(f"Invalid checksum")

yield data

self.change_baudrate(prev_baudrate)
self.pop_timeout()
info("Flash Read Successful.")

def flash_write(
self,
offset: int,
Expand Down