Where MCP = Maximum Controlled Priority
This commit adds:
* seL4_TCB_SetMCPriority
and changes the arguments to
* seL4_TCB_Configure
As of this commit, a thread cannot create or set a threads
priority (including itself) above its mcp. Previously the kernel
did this check against a threads priority, which prevented a thread
from setting it's own priority down and then up again.
The previous macro computed to (0 - sizeof(tcb_t)). Basically a negative
number, which is just a really big unsigned number, so this macro was
basically allowing TCB naming of any length.
The previous definition of TCB_NAME_LENGTH assumed that the TCB was
split evenly into the cnode region and the rest. It did this by
calculating the size of the rest by using the size of the cnode
region. In actual fact the cnode region might be smaller, making
the size of the rest the size of the total tcb block size, minus
the cnode size. The max name length is therefore this region, minus
the size of the tcb_t
