flashbdev and flash size

[devnull]

in flashbdev, the flash size appears to be hard-coded to 512MB:

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(2048 * 1024) / 4096 = 512MB

But given that devices have different size flash, can this be calculated automagically ?

As the esp32 wroom and esp32-thing both 4MB of flash space, how much can I safely define ?

If I correctly understand, this would be 2MB ?

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SEC_SIZE = 4096
MB1 = 2   ## Megabytes
bdev = FlashBdev(((MB1 * 4096) * 1024) // FlashBdev.SEC_SIZE)

When I perform this calc using micropython console, the result is 2MB:

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>>> MB1 = 2   ## Megabytes
>>> SEC_SIZE = 4096
>>> ((MB1 * 4096) * 1024) // SEC_SIZE
2048
>>> 

However, after building and flashing the device, the flash size is actually 8MB ??

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>>> import os
>>> s = os.statvfs('//')
>>> ('{0} MB'.format((s[0]*s[3])/1048576))
'7.972656 MB'
>>> 

[devnull]

Well I am a little confused over the built-in flash size for the ESP32-WROOM.

I thought it was 4MB, however during erase flash, it takes less than half the time to erase (4 secs) than the esp32 thing takes (10 secs) ?

[Roberthh]

In flashbdev.py, the size is hard coded to 2 MByte.
(2048 * 1024) / 4096 = 512 is the number of blocks of 4k each, not MBytes, and that's to be told to FlashBdev()
In the flashbdev.py version here viewtopic.php?f=12&t=3456 the size is calculated from the flash size, like it#s been done on the esp8266.