1 = Low-Level CPU Routines = 2 3 The `lib/cpu.S` file contains low-level routines for handling specific 4 conditions related to the operation of the CPU: 5 6 `init_interrupts` :: Configures the location of exception and interrupt 7 vectors. 8 9 `enable_interrupts` :: Enables the delivery of interrupts to the configured 10 non-bootloader vectors. 11 12 `handle_error_level`:: Handles the initial state of the CPU, making exception 13 and interrupt conditions possible. 14 15 These routines are called in an appropriate order in the general [[../init| 16 initialisation]] code. 17 18 To support exceptions and interrupts, the following routines are defined in 19 the `.vectors` section of the payload: 20 21 `ebase` :: Handles TLB exceptions, jumping to the general exception 22 handler. The PIC32 products tested with this software do not 23 provide hardware that should raise such exceptions, however. 24 25 `exc_handler` :: Handles exception conditions, switching to a dedicated stack 26 and jumping to the `exception_handler` routine defined by an 27 application. 28 29 `int_handler` :: Handles interrupt conditions, switching to a dedicated 30 stack, saving register values, jumping to the 31 `interrupt_handler` routine defined by an application, then 32 restoring register values, switching back to the application 33 stack and returning to the interrupted code.
