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#include <common.h>
#include <command.h>
/* read co-processor 15, register #1 (control register) */
static unsigned long read_p15_c1 (void)
{
unsigned long value;
__asm__ __volatile__(
"mrc p15, 0, %0, c1, c0, 0 @ read control reg\n"
: "=r" (value)
:
: "memory");
#ifdef MMU_DEBUG
printf ("p15/c1 is = %08lx\n", value);
#endif
return value;
}
/* write to co-processor 15, register #1 (control register) */
static void write_p15_c1 (unsigned long value)
{
#ifdef MMU_DEBUG
printf ("write %08lx to p15/c1\n", value);
#endif
__asm__ __volatile__(
"mcr p15, 0, %0, c1, c0, 0 @ write it back\n"
:
: "r" (value)
: "memory");
read_p15_c1 ();
}
static void cp_delay (void)
{
volatile int i;
/* copro seems to need some delay between reading and writing */
for (i = 0; i < 100; i++);
}
#define C1_MMU (1<<0) /* mmu off/on */
#define C1_ALIGN (1<<1) /* alignment faults off/on */
#define C1_DC (1<<2) /* dcache off/on */
#define C1_BIG_ENDIAN (1<<7) /* big endian off/on */
#define C1_SYS_PROT (1<<8) /* system protection */
#define C1_ROM_PROT (1<<9) /* ROM protection */
#define C1_IC (1<<12) /* icache off/on */
#define C1_HIGH_VECTORS (1<<13) /* location of vectors: low/high addresses */
void icache_enable (void)
{
ulong reg;
reg = read_p15_c1 (); /* get control reg. */
cp_delay ();
write_p15_c1 (reg | C1_IC);
}
void icache_disable (void)
{
ulong reg;
reg = read_p15_c1 ();
cp_delay ();
write_p15_c1 (reg & ~C1_IC);
}
int icache_status (void)
{
return (read_p15_c1 () & C1_IC) != 0;
}
/*
* this function is called just before we call linux
* it prepares the processor for linux
*/
int cleanup_before_linux (void)
{
int i;
/*
* we never enable dcache so we do not need to disable
* it. Linux can be called with icache enabled, so just
* do nothing here
*/
/* flush I/D-cache */
i = 0;
asm ("mcr p15, 0, %0, c7, c7, 0": :"r" (i));
return (0);
}
#ifdef CONFIG_USE_IRQ
static int cpu_init (void)
{
/*
* setup up stacks if necessary
*/
IRQ_STACK_START = _u_boot_start - CFG_MALLOC_LEN - CFG_GBL_DATA_SIZE - 4;
FIQ_STACK_START = IRQ_STACK_START - CONFIG_STACKSIZE_IRQ;
return 0;
}
core_initcall(cpu_init);
#endif
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