It's initialized by the linker command file .like this:
/* Define output sections */
SECTIONS
{
/* The startup code goes first into Flash */
.interrupts :
{
__vector_table = .;
. = ALIGN(4);
KEEP(*(.vectortable)) /* Startup code */
. = ALIGN(4);
} > m_interrupts
for more detailed explaination,I guess the FAE will give better answer.
Wish you good