spi_flash_read fails above 512K for a 4M flash

[sake402]

I have an ESP12.

Reading flash below 512k is successful, but not above.

I confirmed that the flash is 4M with esp_tool

Code: Select all

esptool.py v1.2-dev
Connecting...
Manufacturer: ef
Device: 4016


And I successfully loaded a 128KBytes spiff binary at address 0x3D7000

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esptool.py --port COM1 write_flash 0x3D7000 output/data.bin
esptool.py v1.2-dev
Connecting...
Running Cesanta flasher stub...
Writing 131072 @ 0x3d7000... 0 (0 %)
Wrote 131072 bytes at 0x3d7000 in 11.7 seconds (89.7 kbit/s)...
Leaving...


But in the code, attempting to read the spiff binary fails

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SPIFF: Reading flash address: 0x3d70fe size: 2
SPIFF: Reading flash fails @ address 0x3d70fc

I am using the RTOS SDK

[pratik]

SPIFF: Reading flash address: 0x3d70fe size: 2

What does the size:2 mean in your log? Does it mean you are reading 2 bytes?

[sake402]

Yes

And the second line means the address is adjusted to 4 byte alignment before reading

[pratik]

Not sure what function is accessing the flash, so cannot exactly say, but you should probably try reading in multiples of 4 bytes as well. Like for 2 bytes, read 4 and use first 2 bytes, don't just read two.
That might solve your issue.

[sake402]

Yes.
I never read two byte. If you check the log again you 'll notice FE was warped to FC in order to read four bytes.