A simple block device kernel module implementation example.
The module allocates a 100MB buffer in RAM which is accessible (read/write) via a block device:
/dev/ias_blkdev
To get detailed comentry about the block device's flow in the kernel log define IAS_DEBUG in ias_blkdev.c.
If the kernel is configured with CONFIG_DEBUG_FS=y, then building with IAS_DEBUG defined will also result in creating a
debugfs dump file to directly export (read) the content of the RAM buffer:
/sys/kernel/debug/ias/dump
Use it together with xxd to get a human readable hexdump representation of the buffer:
cat /sys/kernel/debug/ias/dump | xxd | less