#include "vhex/driver.h"
#include "vhex/drivers/mpu/sh/sh7305/cpu.h"

#include <string.h>

/* define the private CPU context structure */
struct cpu_ctx {
	uintptr_t vbr;
	cpu_cpuopm_t cpuopm;
	cpu_sr_t sr;
};

/* hardware configuration call */

/* __cpu_configure() : configure the CPU */
static void __cpu_configure(struct cpu_ctx *state)
{
	extern uintptr_t vhex_vbr;

	memset(state, 0x00, sizeof(struct cpu_ctx));

	/* by default, use the vhex VBR */
	state->vbr = (uintptr_t)&vhex_vbr;

	/* configure the CPU Operation Mode
	    <> enable speculative execution (rip Spectre)
	    <> enable SR.IMASK update when an interruption occur */
	state->cpuopm.RABD = 0;
	state->cpuopm.INTMU = 1;
	state->cpuopm._HIGH = 0b1111;

	/* configure the Status Register
	    <> force the privileged mode
	    <> enable DSP
	    <> allow interruptions */
	state->sr.MD  = 1;
	state->sr.RB  = 0;
	state->sr.BL  = 0;
	state->sr.DSP = 1;
	state->sr.IMASK = 0b0000;
}

/* hardware hypervisor call */

/* __cpu_hsave() : save hardware information */
static void __cpu_hsave(struct cpu_ctx *state)
{
	state->vbr = cpu_get_vbr();
	state->cpuopm = cpu_get_cpuopm();
	state->sr = cpu_get_sr();
}

/* __cpu_hrestore() : restore hardware information */
static void __cpu_hrestore(struct cpu_ctx *state)
{
	cpu_set_vbr(state->vbr);
	cpu_set_cpuopm(state->cpuopm);
	cpu_set_sr(state->sr);
}

/* declare the CPU driver */

struct vhex_driver drv_cpu = {
	.name       = "CPU",
	.hsave      = (void*)&__cpu_hsave,
	.hrestore   = (void*)&__cpu_hrestore,
	.configure  = (void*)&__cpu_configure,
	.state_size = sizeof(struct cpu_ctx)
};
VHEX_DECLARE_DRIVER(16, drv_cpu);