Previous implementation was not compatible with GlobalPlatform
API in the following ways:
- Registered mem IDs would begin from negatives when it should
have been greater than or equal to 0
- Register IOCTL would return 0 on success, when it should have
been returning a file descriptor.
- Register IOCTL would expect the user-space client to specify
TEE_SHM_* flags dictating its behaviour when in fact, libteec
never specifies flags.
This commit fixes all those issues. It uses nuttx/idr.h instead
of a linked list, and it uses `file_allocate` to provide file
descriptors for registered shared memory. Upon close(fd), the
memory is de-registered and freed accordingly. It also updates
the documentation accordingly.
Signed-off-by: George Poulios <gpoulios@census-labs.com>
a2a689fee0