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#include "io.h"
#include "uart.h"
#include "svc_interface.h"
#include "armclock.h"
#include "scheduler.h"
void undefined_instruction_vector(void)
{
error("Undefined instruction occured");
}
uint32_t supervisor_call_handler(uint32_t regs[14])
{
switch(regs[0]) {
case UART_PUTCHAR:
if (putchar_non_blocking(regs[1]))
schedule_wait_for_output(regs, regs[1]);
break;
case UART_GETCHAR:
{
int c;
if ((c = getchar_non_blocking()) == -1)
schedule_wait_for_input(regs);
regs[0] = c;
break;
}
case UART_WRITE:
error("UART_WRITE not implemented!!!!!");
break;
default:
// perhaps we should kill the process now?
error("unknown supervisor call type!!!!!");
}
return 0; // a dummy value
}
void abort_handler(void)
{
// TODO maybe dump registers here?
error("re-entered system due to data/prefetch abort");
}
void generic_handler(void)
{
error("something weird happened");
}
void irq_handler(uint32_t regs[14])
{
if (armclk_irq_pending())
{
write_SPSR(PL1_PSR);
asm volatile("mov r0, %[context]\n\r"
"mov lr, %[return_func]\n\r"
"subs pc, lr, #0" ::
[context]"r" (regs),
[return_func]"r" (schedule_save_context) :
"memory");
}
else if (uart_irq_pending())
{
if (uart_recv_irq_pending())
{
uart_clear_recv_irq();
scheduler_try_input();
}
if (uart_send_irq_pending())
{
uart_clear_send_irq();
scheduler_try_output();
}
if (read_SPSR().fields.PSR_MODE_4_0 != MODE_USER)
{
// TODO set supervisor mode's stack pointer
write_SPSR(PL1_PSR);
asm volatile("mov lr, %0\n\r"
"subs pc, lr, #0" ::
"r" (schedule) : "memory");
}
}
else
error("unknown irq");
// important - don't allow this handler to return if irq came from
// PL1 (likely supervisor, because we don't really use system) mode
}
void fiq_handler(void)
{
error("fiq happened");
}
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