Charlie Jacobsen authored Jun 20, 2014 and Vikram Narayanan committed Oct 25, 2016

User code calls ioctl with LCD_RUN_BLOB ioctl number and
lcd_blob_info (containing userspace address of blob and
blob order) -- defined in public include/linux/lcd-domains.h.

The blob must be N pages, and N must be a power of 2 (for
easy driver code). blob_order = log2(N). The blob consists
of machine instructions that are loaded in the lcd and
executed. The machine instructions cannot access any memory,
including the stack (for now, until gv paging is in place).

-- Added lcd_arch_set_pc for setting the lcd's program counter.
-- Added driver code in lcd-domains.c for handling the ioctl
   request, loading the blob from user space into a fresh lcd,
   and running the lcd (in a loop).