A system table called Interrupt Descriptor Table (IDT) associates each interrupt or exception vector with the address of the corresponding interrupt or exception handler. The IDT must be properly initialized before the kernel enables interrupts.
The IDT format is similar to that of the GDT and of the LDTs each entry corresponds to an interrupt or an exception vector and consists of an 8-byte descriptor.
Thus, a maximum of 256x 8=2048 bytes are required to store the IDT.
