[qemu.git] / hw / armv7m_nvic.c

/*
 * ARM Nested Vectored Interrupt Controller
 *
 * Copyright (c) 2006-2007 CodeSourcery.
 * Written by Paul Brook
 *
 * This code is licenced under the GPL.
 *
 * The ARMv7M System controller is fairly tightly tied in with the
 * NVIC.  Much of that is also implemented here.
 */

#include "vl.h"
#include "arm_pic.h"

#define GIC_NIRQ 64
#define NCPU 1
#define NVIC 1

/* Only a single "CPU" interface is present.  */
static inline int
gic_get_current_cpu(void)
{
    return 0;
}

static uint32_t nvic_readl(void *opaque, uint32_t offset);
static void nvic_writel(void *opaque, uint32_t offset, uint32_t value);

#include "arm_gic.c"

typedef struct {
    struct {
        uint32_t control;
        uint32_t reload;
        int64_t tick;
        QEMUTimer *timer;
    } systick;
    gic_state *gic;
} nvic_state;

/* qemu timers run at 1GHz.   We want something closer to 1MHz.  */
#define SYSTICK_SCALE 1000ULL

#define SYSTICK_ENABLE    (1 << 0)
#define SYSTICK_TICKINT   (1 << 1)
#define SYSTICK_CLKSOURCE (1 << 2)
#define SYSTICK_COUNTFLAG (1 << 16)

/* Conversion factor from qemu timer to SysTick frequencies.
   QEMU uses a base of 1GHz, so these give 20MHz and 1MHz for core and
   reference frequencies.  */

static inline int64_t systick_scale(nvic_state *s)
{
    if (s->systick.control & SYSTICK_CLKSOURCE)
        return 50;
    else
        return 1000;
}

static void systick_reload(nvic_state *s, int reset)
{
    if (reset)
        s->systick.tick = qemu_get_clock(vm_clock);
    s->systick.tick += (s->systick.reload + 1) * systick_scale(s);
    qemu_mod_timer(s->systick.timer, s->systick.tick);
}

static void systick_timer_tick(void * opaque)
{
    nvic_state *s = (nvic_state *)opaque;
    s->systick.control |= SYSTICK_COUNTFLAG;
    if (s->systick.control & SYSTICK_TICKINT) {
        /* Trigger the interrupt.  */
        armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
    }
    if (s->systick.reload == 0) {
        s->systick.control &= ~SYSTICK_ENABLE;
    } else {
        systick_reload(s, 0);
    }
}

/* The external routines use the hardware vector numbering, ie. the first
   IRQ is #16.  The internal GIC routines use #32 as the first IRQ.  */
void armv7m_nvic_set_pending(void *opaque, int irq)
{
    nvic_state *s = (nvic_state *)opaque;
    if (irq >= 16)
        irq += 16;
    gic_set_pending_private(s->gic, 0, irq);
}

/* Make pending IRQ active.  */
int armv7m_nvic_acknowledge_irq(void *opaque)
{
    nvic_state *s = (nvic_state *)opaque;
    uint32_t irq;

    irq = gic_acknowledge_irq(s->gic, 0);
    if (irq == 1023)
        cpu_abort(cpu_single_env, "Interrupt but no vector\n");
    if (irq >= 32)
        irq -= 16;
    return irq;
}

void armv7m_nvic_complete_irq(void *opaque, int irq)
{
    nvic_state *s = (nvic_state *)opaque;
    if (irq >= 16)
        irq += 16;
    gic_complete_irq(s->gic, 0, irq);
}

static uint32_t nvic_readl(void *opaque, uint32_t offset)
{
    nvic_state *s = (nvic_state *)opaque;
    uint32_t val;
    int irq;

    switch (offset) {
    case 4: /* Interrupt Control Type.  */
        return (GIC_NIRQ / 32) - 1;
    case 0x10: /* SysTick Control and Status.  */
        val = s->systick.control;
        s->systick.control &= ~SYSTICK_COUNTFLAG;
        return val;
    case 0x14: /* SysTick Reload Value.  */
        return s->systick.reload;
    case 0x18: /* SysTick Current Value.  */
        {
            int64_t t;
            if ((s->systick.control & SYSTICK_ENABLE) == 0)
                return 0;
            t = qemu_get_clock(vm_clock);
            if (t >= s->systick.tick)
                return 0;
            val = ((s->systick.tick - (t + 1)) / systick_scale(s)) + 1;
            /* The interrupt in triggered when the timer reaches zero.
               However the counter is not reloaded until the next clock
               tick.  This is a hack to return zero during the first tick.  */
            if (val > s->systick.reload)
                val = 0;
            return val;
        }
    case 0x1c: /* SysTick Calibration Value.  */
        return 10000;
    case 0xd00: /* CPUID Base.  */
        return cpu_single_env->cp15.c0_cpuid;
    case 0xd04: /* Interrypt Control State.  */
        /* VECTACTIVE */
        val = s->gic->running_irq[0];
        if (val == 1023) {
            val = 0;
        } else if (val >= 32) {
            val -= 16;
        }
        /* RETTOBASE */
        if (s->gic->running_irq[0] == 1023
                || s->gic->last_active[s->gic->running_irq[0]][0] == 1023) {
            val |= (1 << 11);
        }
        /* VECTPENDING */
        if (s->gic->current_pending[0] != 1023)
            val |= (s->gic->current_pending[0] << 12);
        /* ISRPENDING */
        for (irq = 32; irq < GIC_NIRQ; irq++) {
            if (s->gic->irq_state[irq].pending) {
                val |= (1 << 22);
                break;
            }
        }
        /* PENDSTSET */
        if (s->gic->irq_state[ARMV7M_EXCP_SYSTICK].pending)
            val |= (1 << 26);
        /* PENDSVSET */
        if (s->gic->irq_state[ARMV7M_EXCP_PENDSV].pending)
            val |= (1 << 28);
        /* NMIPENDSET */
        if (s->gic->irq_state[ARMV7M_EXCP_NMI].pending)
            val |= (1 << 31);
        return val;
    case 0xd08: /* Vector Table Offset.  */
        return cpu_single_env->v7m.vecbase;
    case 0xd0c: /* Application Interrupt/Reset Control.  */
        return 0xfa05000;
    case 0xd10: /* System Control.  */
        /* TODO: Implement SLEEPONEXIT.  */
        return 0;
    case 0xd14: /* Configuration Control.  */
        /* TODO: Implement Configuration Control bits.  */
        return 0;
    case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority.  */
        irq = offset - 0xd14;
        val = 0;
        val = s->gic->priority1[irq++][0];
        val = s->gic->priority1[irq++][0] << 8;
        val = s->gic->priority1[irq++][0] << 16;
        val = s->gic->priority1[irq][0] << 24;
        return val;
    case 0xd24: /* System Handler Status.  */
        val = 0;
        if (s->gic->irq_state[ARMV7M_EXCP_MEM].active) val |= (1 << 0);
        if (s->gic->irq_state[ARMV7M_EXCP_BUS].active) val |= (1 << 1);
        if (s->gic->irq_state[ARMV7M_EXCP_USAGE].active) val |= (1 << 3);
        if (s->gic->irq_state[ARMV7M_EXCP_SVC].active) val |= (1 << 7);
        if (s->gic->irq_state[ARMV7M_EXCP_DEBUG].active) val |= (1 << 8);
        if (s->gic->irq_state[ARMV7M_EXCP_PENDSV].active) val |= (1 << 10);
        if (s->gic->irq_state[ARMV7M_EXCP_SYSTICK].active) val |= (1 << 11);
        if (s->gic->irq_state[ARMV7M_EXCP_USAGE].pending) val |= (1 << 12);
        if (s->gic->irq_state[ARMV7M_EXCP_MEM].pending) val |= (1 << 13);
        if (s->gic->irq_state[ARMV7M_EXCP_BUS].pending) val |= (1 << 14);
        if (s->gic->irq_state[ARMV7M_EXCP_SVC].pending) val |= (1 << 15);
        if (s->gic->irq_state[ARMV7M_EXCP_MEM].enabled) val |= (1 << 16);
        if (s->gic->irq_state[ARMV7M_EXCP_BUS].enabled) val |= (1 << 17);
        if (s->gic->irq_state[ARMV7M_EXCP_USAGE].enabled) val |= (1 << 18);
        return val;
    case 0xd28: /* Configurable Fault Status.  */
        /* TODO: Implement Fault Status.  */
        cpu_abort(cpu_single_env,
                  "Not implemented: Configurable Fault Status.");
        return 0;
    case 0xd2c: /* Hard Fault Status.  */
    case 0xd30: /* Debug Fault Status.  */
    case 0xd34: /* Mem Manage Address.  */
    case 0xd38: /* Bus Fault Address.  */
    case 0xd3c: /* Aux Fault Status.  */
        /* TODO: Implement fault status registers.  */
        goto bad_reg;
    case 0xd40: /* PFR0.  */
        return 0x00000030;
    case 0xd44: /* PRF1.  */
        return 0x00000200;
    case 0xd48: /* DFR0.  */
        return 0x00100000;
    case 0xd4c: /* AFR0.  */
        return 0x00000000;
    case 0xd50: /* MMFR0.  */
        return 0x00000030;
    case 0xd54: /* MMFR1.  */
        return 0x00000000;
    case 0xd58: /* MMFR2.  */
        return 0x00000000;
    case 0xd5c: /* MMFR3.  */
        return 0x00000000;
    case 0xd60: /* ISAR0.  */
        return 0x01141110;
    case 0xd64: /* ISAR1.  */
        return 0x02111000;
    case 0xd68: /* ISAR2.  */
        return 0x21112231;
    case 0xd6c: /* ISAR3.  */
        return 0x01111110;
    case 0xd70: /* ISAR4.  */
        return 0x01310102;
    /* TODO: Implement debug registers.  */
    default:
    bad_reg:
        cpu_abort(cpu_single_env, "NVIC: Bad read offset 0x%x\n", offset);
    }
}

static void nvic_writel(void *opaque, uint32_t offset, uint32_t value)
{
    nvic_state *s = (nvic_state *)opaque;
    uint32_t oldval;
    switch (offset) {
    case 0x10: /* SysTick Control and Status.  */
        oldval = s->systick.control;
        s->systick.control &= 0xfffffff8;
        s->systick.control |= value & 7;
        if ((oldval ^ value) & SYSTICK_ENABLE) {
            int64_t now = qemu_get_clock(vm_clock);
            if (value & SYSTICK_ENABLE) {
                if (s->systick.tick) {
                    s->systick.tick += now;
                    qemu_mod_timer(s->systick.timer, s->systick.tick);
                } else {
                    systick_reload(s, 1);
                }
            } else {
                qemu_del_timer(s->systick.timer);
                s->systick.tick -= now;
                if (s->systick.tick < 0)
                  s->systick.tick = 0;
            }
        } else if ((oldval ^ value) & SYSTICK_CLKSOURCE) {
            /* This is a hack. Force the timer to be reloaded
               when the reference clock is changed.  */
            systick_reload(s, 1);
        }
        break;
    case 0x14: /* SysTick Reload Value.  */
        s->systick.reload = value;
        break;
    case 0x18: /* SysTick Current Value.  Writes reload the timer.  */
        systick_reload(s, 1);
        s->systick.control &= ~SYSTICK_COUNTFLAG;
        break;
    case 0xd04: /* Interrupt Control State.  */
        if (value & (1 << 31)) {
            armv7m_nvic_set_pending(s, ARMV7M_EXCP_NMI);
        }
        if (value & (1 << 28)) {
            armv7m_nvic_set_pending(s, ARMV7M_EXCP_PENDSV);
        } else if (value & (1 << 27)) {
            s->gic->irq_state[ARMV7M_EXCP_PENDSV].pending = 0;
            gic_update(s->gic);
        }
        if (value & (1 << 26)) {
            armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
        } else if (value & (1 << 25)) {
            s->gic->irq_state[ARMV7M_EXCP_SYSTICK].pending = 0;
            gic_update(s->gic);
        }
        break;
    case 0xd08: /* Vector Table Offset.  */
        cpu_single_env->v7m.vecbase = value & 0xffffff80;
        break;
    case 0xd0c: /* Application Interrupt/Reset Control.  */
        if ((value >> 16) == 0x05fa) {
            if (value & 2) {
                cpu_abort(cpu_single_env, "VECTCLRACTIVE not implemented");
            }
            if (value & 5) {
                cpu_abort(cpu_single_env, "System reset");
            }
        }
        break;
    case 0xd10: /* System Control.  */
    case 0xd14: /* Configuration Control.  */
        /* TODO: Implement control registers.  */
        goto bad_reg;
    case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority.  */
        {
            int irq;
            irq = offset - 0xd14;
            s->gic->priority1[irq++][0] = value & 0xff;
            s->gic->priority1[irq++][0] = (value >> 8) & 0xff;
            s->gic->priority1[irq++][0] = (value >> 16) & 0xff;
            s->gic->priority1[irq][0] = (value >> 24) & 0xff;
            gic_update(s->gic);
        }
        break;
    case 0xd24: /* System Handler Control.  */
        /* TODO: Real hardware allows you to set/clear the active bits
           under some circumstances.  We don't implement this.  */
        s->gic->irq_state[ARMV7M_EXCP_MEM].enabled = (value & (1 << 16)) != 0;
        s->gic->irq_state[ARMV7M_EXCP_BUS].enabled = (value & (1 << 17)) != 0;
        s->gic->irq_state[ARMV7M_EXCP_USAGE].enabled = (value & (1 << 18)) != 0;
        break;
    case 0xd28: /* Configurable Fault Status.  */
    case 0xd2c: /* Hard Fault Status.  */
    case 0xd30: /* Debug Fault Status.  */
    case 0xd34: /* Mem Manage Address.  */
    case 0xd38: /* Bus Fault Address.  */
    case 0xd3c: /* Aux Fault Status.  */
        goto bad_reg;
    default:
    bad_reg:
        cpu_abort(cpu_single_env, "NVIC: Bad write offset 0x%x\n", offset);
    }
}

qemu_irq *armv7m_nvic_init(CPUState *env)
{
    nvic_state *s;
    qemu_irq *parent;

    parent = arm_pic_init_cpu(env);
    s = (nvic_state *)qemu_mallocz(sizeof(nvic_state));
    s->gic = gic_init(0xe000e000, &parent[ARM_PIC_CPU_IRQ]);
    s->gic->nvic = s;
    s->systick.timer = qemu_new_timer(vm_clock, systick_timer_tick, s);
    if (env->v7m.nvic)
        cpu_abort(env, "CPU can only have one NVIC\n");
    env->v7m.nvic = s;
    return s->gic->in;
}
Commit	Line	Data
9ee6e8bb PB	1	/*
	2	* ARM Nested Vectored Interrupt Controller
	3	*
	4	* Copyright (c) 2006-2007 CodeSourcery.
	5	* Written by Paul Brook
	6	*
	7	* This code is licenced under the GPL.
	8	*
	9	* The ARMv7M System controller is fairly tightly tied in with the
	10	* NVIC. Much of that is also implemented here.
	11	*/
	12
	13	#include "vl.h"
	14	#include "arm_pic.h"
	15
	16	#define GIC_NIRQ 64
	17	#define NCPU 1
	18	#define NVIC 1
	19
	20	/* Only a single "CPU" interface is present. */
	21	static inline int
	22	gic_get_current_cpu(void)
	23	{
	24	return 0;
	25	}
	26
	27	static uint32_t nvic_readl(void *opaque, uint32_t offset);
	28	static void nvic_writel(void *opaque, uint32_t offset, uint32_t value);
	29
	30	#include "arm_gic.c"
	31
	32	typedef struct {
	33	struct {
	34	uint32_t control;
	35	uint32_t reload;
	36	int64_t tick;
	37	QEMUTimer *timer;
	38	} systick;
	39	gic_state *gic;
	40	} nvic_state;
	41
	42	/* qemu timers run at 1GHz. We want something closer to 1MHz. */
	43	#define SYSTICK_SCALE 1000ULL
	44
	45	#define SYSTICK_ENABLE (1 << 0)
	46	#define SYSTICK_TICKINT (1 << 1)
	47	#define SYSTICK_CLKSOURCE (1 << 2)
	48	#define SYSTICK_COUNTFLAG (1 << 16)
	49
	50	/* Conversion factor from qemu timer to SysTick frequencies.
	51	QEMU uses a base of 1GHz, so these give 20MHz and 1MHz for core and
	52	reference frequencies. */
	53
	54	static inline int64_t systick_scale(nvic_state *s)
	55	{
	56	if (s->systick.control & SYSTICK_CLKSOURCE)
	57	return 50;
	58	else
	59	return 1000;
	60	}
	61
	62	static void systick_reload(nvic_state *s, int reset)
	63	{
	64	if (reset)
65	s->systick.tick = qemu_get_clock(vm_clock);
66	s->systick.tick += (s->systick.reload + 1) * systick_scale(s);
67	qemu_mod_timer(s->systick.timer, s->systick.tick);
68	}
69
70	static void systick_timer_tick(void * opaque)
71	{
72	nvic_state s = (nvic_state )opaque;
73	s->systick.control \|= SYSTICK_COUNTFLAG;
74	if (s->systick.control & SYSTICK_TICKINT) {
75	/* Trigger the interrupt. */
76	armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
77	}
78	if (s->systick.reload == 0) {
79	s->systick.control &= ~SYSTICK_ENABLE;
80	} else {
81	systick_reload(s, 0);
82	}
83	}
84
85	/* The external routines use the hardware vector numbering, ie. the first
86	IRQ is #16. The internal GIC routines use #32 as the first IRQ. */
87	void armv7m_nvic_set_pending(void *opaque, int irq)
88	{
89	nvic_state s = (nvic_state )opaque;
90	if (irq >= 16)
91	irq += 16;
92	gic_set_pending_private(s->gic, 0, irq);
93	}
94
95	/* Make pending IRQ active. */
96	int armv7m_nvic_acknowledge_irq(void *opaque)
97	{
98	nvic_state s = (nvic_state )opaque;
99	uint32_t irq;
100
101	irq = gic_acknowledge_irq(s->gic, 0);
102	if (irq == 1023)
103	cpu_abort(cpu_single_env, "Interrupt but no vector\n");
104	if (irq >= 32)
105	irq -= 16;
106	return irq;
107	}
108
109	void armv7m_nvic_complete_irq(void *opaque, int irq)
110	{
111	nvic_state s = (nvic_state )opaque;
112	if (irq >= 16)
113	irq += 16;
114	gic_complete_irq(s->gic, 0, irq);
115	}
116
117	static uint32_t nvic_readl(void *opaque, uint32_t offset)
118	{
119	nvic_state s = (nvic_state )opaque;
120	uint32_t val;
121	int irq;
122
123	switch (offset) {
124	case 4: /* Interrupt Control Type. */
125	return (GIC_NIRQ / 32) - 1;
126	case 0x10: /* SysTick Control and Status. */
127	val = s->systick.control;
128	s->systick.control &= ~SYSTICK_COUNTFLAG;
129	return val;
130	case 0x14: /* SysTick Reload Value. */
131	return s->systick.reload;
132	case 0x18: /* SysTick Current Value. */
133	{
134	int64_t t;
135	if ((s->systick.control & SYSTICK_ENABLE) == 0)
136	return 0;
137	t = qemu_get_clock(vm_clock);
138	if (t >= s->systick.tick)
139	return 0;
140	val = ((s->systick.tick - (t + 1)) / systick_scale(s)) + 1;
141	/* The interrupt in triggered when the timer reaches zero.
142	However the counter is not reloaded until the next clock
143	tick. This is a hack to return zero during the first tick. */
144	if (val > s->systick.reload)
145	val = 0;
146	return val;
147	}
148	case 0x1c: /* SysTick Calibration Value. */
149	return 10000;
150	case 0xd00: /* CPUID Base. */
151	return cpu_single_env->cp15.c0_cpuid;
152	case 0xd04: /* Interrypt Control State. */
153	/* VECTACTIVE */
154	val = s->gic->running_irq[0];
155	if (val == 1023) {
156	val = 0;
157	} else if (val >= 32) {
158	val -= 16;
159	}
160	/* RETTOBASE */
161	if (s->gic->running_irq[0] == 1023
162	\|\| s->gic->last_active[s->gic->running_irq[0]][0] == 1023) {
163	val \|= (1 << 11);
164	}
165	/* VECTPENDING */
166	if (s->gic->current_pending[0] != 1023)
167	val \|= (s->gic->current_pending[0] << 12);
168	/* ISRPENDING */
169	for (irq = 32; irq < GIC_NIRQ; irq++) {
170	if (s->gic->irq_state[irq].pending) {
171	val \|= (1 << 22);
172	break;
173	}
174	}
175	/* PENDSTSET */
176	if (s->gic->irq_state[ARMV7M_EXCP_SYSTICK].pending)
177	val \|= (1 << 26);
178	/* PENDSVSET */
179	if (s->gic->irq_state[ARMV7M_EXCP_PENDSV].pending)
180	val \|= (1 << 28);
181	/* NMIPENDSET */
182	if (s->gic->irq_state[ARMV7M_EXCP_NMI].pending)
183	val \|= (1 << 31);
184	return val;
185	case 0xd08: /* Vector Table Offset. */
186	return cpu_single_env->v7m.vecbase;
187	case 0xd0c: /* Application Interrupt/Reset Control. */
188	return 0xfa05000;
189	case 0xd10: /* System Control. */
190	/* TODO: Implement SLEEPONEXIT. */
191	return 0;
192	case 0xd14: /* Configuration Control. */
193	/* TODO: Implement Configuration Control bits. */
194	return 0;
195	case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority. */
196	irq = offset - 0xd14;
197	val = 0;
198	val = s->gic->priority1[irq++][0];
199	val = s->gic->priority1[irq++][0] << 8;
200	val = s->gic->priority1[irq++][0] << 16;
201	val = s->gic->priority1[irq][0] << 24;
202	return val;
203	case 0xd24: /* System Handler Status. */
204	val = 0;
205	if (s->gic->irq_state[ARMV7M_EXCP_MEM].active) val \|= (1 << 0);
206	if (s->gic->irq_state[ARMV7M_EXCP_BUS].active) val \|= (1 << 1);
207	if (s->gic->irq_state[ARMV7M_EXCP_USAGE].active) val \|= (1 << 3);
208	if (s->gic->irq_state[ARMV7M_EXCP_SVC].active) val \|= (1 << 7);
209	if (s->gic->irq_state[ARMV7M_EXCP_DEBUG].active) val \|= (1 << 8);
210	if (s->gic->irq_state[ARMV7M_EXCP_PENDSV].active) val \|= (1 << 10);
211	if (s->gic->irq_state[ARMV7M_EXCP_SYSTICK].active) val \|= (1 << 11);
212	if (s->gic->irq_state[ARMV7M_EXCP_USAGE].pending) val \|= (1 << 12);
213	if (s->gic->irq_state[ARMV7M_EXCP_MEM].pending) val \|= (1 << 13);
214	if (s->gic->irq_state[ARMV7M_EXCP_BUS].pending) val \|= (1 << 14);
215	if (s->gic->irq_state[ARMV7M_EXCP_SVC].pending) val \|= (1 << 15);
216	if (s->gic->irq_state[ARMV7M_EXCP_MEM].enabled) val \|= (1 << 16);
217	if (s->gic->irq_state[ARMV7M_EXCP_BUS].enabled) val \|= (1 << 17);
218	if (s->gic->irq_state[ARMV7M_EXCP_USAGE].enabled) val \|= (1 << 18);
219	return val;
220	case 0xd28: /* Configurable Fault Status. */
221	/* TODO: Implement Fault Status. */
222	cpu_abort(cpu_single_env,
223	"Not implemented: Configurable Fault Status.");
224	return 0;
225	case 0xd2c: /* Hard Fault Status. */
226	case 0xd30: /* Debug Fault Status. */
227	case 0xd34: /* Mem Manage Address. */
228	case 0xd38: /* Bus Fault Address. */
229	case 0xd3c: /* Aux Fault Status. */
230	/* TODO: Implement fault status registers. */
231	goto bad_reg;
232	case 0xd40: /* PFR0. */
233	return 0x00000030;
234	case 0xd44: /* PRF1. */
235	return 0x00000200;
236	case 0xd48: /* DFR0. */
237	return 0x00100000;
238	case 0xd4c: /* AFR0. */
239	return 0x00000000;
240	case 0xd50: /* MMFR0. */
241	return 0x00000030;
242	case 0xd54: /* MMFR1. */
243	return 0x00000000;
244	case 0xd58: /* MMFR2. */
245	return 0x00000000;
246	case 0xd5c: /* MMFR3. */
247	return 0x00000000;
248	case 0xd60: /* ISAR0. */
249	return 0x01141110;
250	case 0xd64: /* ISAR1. */
251	return 0x02111000;
252	case 0xd68: /* ISAR2. */
253	return 0x21112231;
254	case 0xd6c: /* ISAR3. */
255	return 0x01111110;
256	case 0xd70: /* ISAR4. */
257	return 0x01310102;
258	/* TODO: Implement debug registers. */
259	default:
260	bad_reg:
261	cpu_abort(cpu_single_env, "NVIC: Bad read offset 0x%x\n", offset);
262	}
263	}
264
265	static void nvic_writel(void *opaque, uint32_t offset, uint32_t value)
266	{
267	nvic_state s = (nvic_state )opaque;
268	uint32_t oldval;
269	switch (offset) {
270	case 0x10: /* SysTick Control and Status. */
271	oldval = s->systick.control;
272	s->systick.control &= 0xfffffff8;
273	s->systick.control \|= value & 7;
274	if ((oldval ^ value) & SYSTICK_ENABLE) {
275	int64_t now = qemu_get_clock(vm_clock);
276	if (value & SYSTICK_ENABLE) {
277	if (s->systick.tick) {
278	s->systick.tick += now;
279	qemu_mod_timer(s->systick.timer, s->systick.tick);
280	} else {
281	systick_reload(s, 1);
282	}
283	} else {
284	qemu_del_timer(s->systick.timer);
285	s->systick.tick -= now;
286	if (s->systick.tick < 0)
287	s->systick.tick = 0;
288	}
289	} else if ((oldval ^ value) & SYSTICK_CLKSOURCE) {
290	/* This is a hack. Force the timer to be reloaded
291	when the reference clock is changed. */
292	systick_reload(s, 1);
293	}
294	break;
295	case 0x14: /* SysTick Reload Value. */
296	s->systick.reload = value;
297	break;
298	case 0x18: /* SysTick Current Value. Writes reload the timer. */
299	systick_reload(s, 1);
300	s->systick.control &= ~SYSTICK_COUNTFLAG;
301	break;
302	case 0xd04: /* Interrupt Control State. */
303	if (value & (1 << 31)) {
304	armv7m_nvic_set_pending(s, ARMV7M_EXCP_NMI);
305	}
306	if (value & (1 << 28)) {
307	armv7m_nvic_set_pending(s, ARMV7M_EXCP_PENDSV);
308	} else if (value & (1 << 27)) {
309	s->gic->irq_state[ARMV7M_EXCP_PENDSV].pending = 0;
310	gic_update(s->gic);
311	}
312	if (value & (1 << 26)) {
313	armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
314	} else if (value & (1 << 25)) {
315	s->gic->irq_state[ARMV7M_EXCP_SYSTICK].pending = 0;
316	gic_update(s->gic);
317	}
318	break;
319	case 0xd08: /* Vector Table Offset. */
320	cpu_single_env->v7m.vecbase = value & 0xffffff80;
321	break;
322	case 0xd0c: /* Application Interrupt/Reset Control. */
323	if ((value >> 16) == 0x05fa) {
324	if (value & 2) {
325	cpu_abort(cpu_single_env, "VECTCLRACTIVE not implemented");
326	}
327	if (value & 5) {
328	cpu_abort(cpu_single_env, "System reset");
329	}
330	}
331	break;
332	case 0xd10: /* System Control. */
333	case 0xd14: /* Configuration Control. */
334	/* TODO: Implement control registers. */
335	goto bad_reg;
336	case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority. */
337	{
338	int irq;
339	irq = offset - 0xd14;
340	s->gic->priority1[irq++][0] = value & 0xff;
341	s->gic->priority1[irq++][0] = (value >> 8) & 0xff;
342	s->gic->priority1[irq++][0] = (value >> 16) & 0xff;
343	s->gic->priority1[irq][0] = (value >> 24) & 0xff;
344	gic_update(s->gic);
345	}
346	break;
347	case 0xd24: /* System Handler Control. */
348	/* TODO: Real hardware allows you to set/clear the active bits
349	under some circumstances. We don't implement this. */
350	s->gic->irq_state[ARMV7M_EXCP_MEM].enabled = (value & (1 << 16)) != 0;
351	s->gic->irq_state[ARMV7M_EXCP_BUS].enabled = (value & (1 << 17)) != 0;
352	s->gic->irq_state[ARMV7M_EXCP_USAGE].enabled = (value & (1 << 18)) != 0;
353	break;
354	case 0xd28: /* Configurable Fault Status. */
355	case 0xd2c: /* Hard Fault Status. */
356	case 0xd30: /* Debug Fault Status. */
357	case 0xd34: /* Mem Manage Address. */
358	case 0xd38: /* Bus Fault Address. */
359	case 0xd3c: /* Aux Fault Status. */
360	goto bad_reg;
361	default:
362	bad_reg:
363	cpu_abort(cpu_single_env, "NVIC: Bad write offset 0x%x\n", offset);
364	}
365	}
366
367	qemu_irq armv7m_nvic_init(CPUState env)
368	{
369	nvic_state *s;
370	qemu_irq *parent;
371
372	parent = arm_pic_init_cpu(env);
373	s = (nvic_state *)qemu_mallocz(sizeof(nvic_state));
374	s->gic = gic_init(0xe000e000, &parent[ARM_PIC_CPU_IRQ]);
375	s->gic->nvic = s;
376	s->systick.timer = qemu_new_timer(vm_clock, systick_timer_tick, s);
377	if (env->v7m.nvic)
378	cpu_abort(env, "CPU can only have one NVIC\n");
379	env->v7m.nvic = s;
380	return s->gic->in;
381	}