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-rw-r--r--hw/arm/fsl-imx25.c11
-rw-r--r--hw/misc/Makefile.objs1
-rw-r--r--hw/misc/imx_rngc.c278
-rw-r--r--include/hw/arm/fsl-imx25.h5
-rw-r--r--include/hw/misc/imx_rngc.h35
5 files changed, 330 insertions, 0 deletions
diff --git a/hw/arm/fsl-imx25.c b/hw/arm/fsl-imx25.c
index 3cb5a8fdfd..da3471b395 100644
--- a/hw/arm/fsl-imx25.c
+++ b/hw/arm/fsl-imx25.c
@@ -62,6 +62,9 @@ static void fsl_imx25_init(Object *obj)
 
     sysbus_init_child_obj(obj, "fec", &s->fec, sizeof(s->fec), TYPE_IMX_FEC);
 
+    sysbus_init_child_obj(obj, "rngc", &s->rngc, sizeof(s->rngc),
+                          TYPE_IMX_RNGC);
+
     for (i = 0; i < FSL_IMX25_NUM_I2CS; i++) {
         sysbus_init_child_obj(obj, "i2c[*]", &s->i2c[i], sizeof(s->i2c[i]),
                               TYPE_IMX_I2C);
@@ -188,6 +191,14 @@ static void fsl_imx25_realize(DeviceState *dev, Error **errp)
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->fec), 0,
                        qdev_get_gpio_in(DEVICE(&s->avic), FSL_IMX25_FEC_IRQ));
 
+    object_property_set_bool(OBJECT(&s->rngc), true, "realized", &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+    sysbus_mmio_map(SYS_BUS_DEVICE(&s->rngc), 0, FSL_IMX25_RNGC_ADDR);
+    sysbus_connect_irq(SYS_BUS_DEVICE(&s->rngc), 0,
+                       qdev_get_gpio_in(DEVICE(&s->avic), FSL_IMX25_RNGC_IRQ));
 
     /* Initialize all I2C */
     for (i = 0; i < FSL_IMX25_NUM_I2CS; i++) {
diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index c6ecbdd7b0..da993f45b7 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -42,6 +42,7 @@ common-obj-$(CONFIG_IMX) += imx7_ccm.o
 common-obj-$(CONFIG_IMX) += imx2_wdt.o
 common-obj-$(CONFIG_IMX) += imx7_snvs.o
 common-obj-$(CONFIG_IMX) += imx7_gpr.o
+common-obj-$(CONFIG_IMX) += imx_rngc.o
 common-obj-$(CONFIG_MILKYMIST) += milkymist-hpdmc.o
 common-obj-$(CONFIG_MILKYMIST) += milkymist-pfpu.o
 common-obj-$(CONFIG_MAINSTONE) += mst_fpga.o
diff --git a/hw/misc/imx_rngc.c b/hw/misc/imx_rngc.c
new file mode 100644
index 0000000000..4c270df2db
--- /dev/null
+++ b/hw/misc/imx_rngc.c
@@ -0,0 +1,278 @@
+/*
+ * Freescale i.MX RNGC emulation
+ *
+ * Copyright (C) 2020 Martin Kaiser <martin@kaiser.cx>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ * This driver provides the minimum functionality to initialize and seed
+ * an rngc and to read random numbers. The rngb that is found in imx25
+ * chipsets is also supported.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/main-loop.h"
+#include "qemu/module.h"
+#include "qemu/log.h"
+#include "qemu/guest-random.h"
+#include "hw/irq.h"
+#include "hw/misc/imx_rngc.h"
+#include "migration/vmstate.h"
+
+#define RNGC_NAME "i.MX RNGC"
+
+#define RNGC_VER_ID  0x00
+#define RNGC_COMMAND 0x04
+#define RNGC_CONTROL 0x08
+#define RNGC_STATUS  0x0C
+#define RNGC_FIFO    0x14
+
+/* These version info are reported by the rngb in an imx258 chip. */
+#define RNG_TYPE_RNGB 0x1
+#define V_MAJ 0x2
+#define V_MIN 0x40
+
+#define RNGC_CMD_BIT_SW_RST    0x40
+#define RNGC_CMD_BIT_CLR_ERR   0x20
+#define RNGC_CMD_BIT_CLR_INT   0x10
+#define RNGC_CMD_BIT_SEED      0x02
+#define RNGC_CMD_BIT_SELF_TEST 0x01
+
+#define RNGC_CTRL_BIT_MASK_ERR  0x40
+#define RNGC_CTRL_BIT_MASK_DONE 0x20
+#define RNGC_CTRL_BIT_AUTO_SEED 0x10
+
+/* the current status for self-test and seed operations */
+#define OP_IDLE 0
+#define OP_RUN  1
+#define OP_DONE 2
+
+static uint64_t imx_rngc_read(void *opaque, hwaddr offset, unsigned size)
+{
+    IMXRNGCState *s = IMX_RNGC(opaque);
+    uint64_t val = 0;
+
+    switch (offset) {
+    case RNGC_VER_ID:
+        val |= RNG_TYPE_RNGB << 28 | V_MAJ << 8 | V_MIN;
+        break;
+
+    case RNGC_COMMAND:
+        if (s->op_seed == OP_RUN) {
+            val |= RNGC_CMD_BIT_SEED;
+        }
+        if (s->op_self_test == OP_RUN) {
+            val |= RNGC_CMD_BIT_SELF_TEST;
+        }
+        break;
+
+    case RNGC_CONTROL:
+        /*
+         * The CTL_ACC and VERIF_MODE bits are not supported yet.
+         * They read as 0.
+         */
+        val |= s->mask;
+        if (s->auto_seed) {
+            val |= RNGC_CTRL_BIT_AUTO_SEED;
+        }
+        /*
+         * We don't have an internal fifo like the real hardware.
+         * There's no need for strategy to handle fifo underflows.
+         * We return the FIFO_UFLOW_RESPONSE bits as 0.
+         */
+        break;
+
+    case RNGC_STATUS:
+        /*
+         * We never report any statistics test or self-test errors or any
+         * other errors. STAT_TEST_PF, ST_PF and ERROR are always 0.
+         */
+
+        /*
+         * We don't have an internal fifo, see above. Therefore, we
+         * report back the default fifo size (5 32-bit words) and
+         * indicate that our fifo is always full.
+         */
+        val |= 5 << 12 | 5 << 8;
+
+        /* We always have a new seed available. */
+        val |= 1 << 6;
+
+        if (s->op_seed == OP_DONE) {
+            val |= 1 << 5;
+        }
+        if (s->op_self_test == OP_DONE) {
+            val |= 1 << 4;
+        }
+        if (s->op_seed == OP_RUN || s->op_self_test == OP_RUN) {
+            /*
+             * We're busy if self-test is running or if we're
+             * seeding the prng.
+             */
+            val |= 1 << 1;
+        } else {
+            /*
+             * We're ready to provide secure random numbers whenever
+             * we're not busy.
+             */
+            val |= 1;
+        }
+        break;
+
+    case RNGC_FIFO:
+        qemu_guest_getrandom_nofail(&val, sizeof(val));
+        break;
+    }
+
+    return val;
+}
+
+static void imx_rngc_do_reset(IMXRNGCState *s)
+{
+    s->op_self_test = OP_IDLE;
+    s->op_seed = OP_IDLE;
+    s->mask = 0;
+    s->auto_seed = false;
+}
+
+static void imx_rngc_write(void *opaque, hwaddr offset, uint64_t value,
+                           unsigned size)
+{
+    IMXRNGCState *s = IMX_RNGC(opaque);
+
+    switch (offset) {
+    case RNGC_COMMAND:
+        if (value & RNGC_CMD_BIT_SW_RST) {
+            imx_rngc_do_reset(s);
+        }
+
+        /*
+         * For now, both CLR_ERR and CLR_INT clear the interrupt. We
+         * don't report any errors yet.
+         */
+        if (value & (RNGC_CMD_BIT_CLR_ERR | RNGC_CMD_BIT_CLR_INT)) {
+            qemu_irq_lower(s->irq);
+        }
+
+        if (value & RNGC_CMD_BIT_SEED) {
+            s->op_seed = OP_RUN;
+            qemu_bh_schedule(s->seed_bh);
+        }
+
+        if (value & RNGC_CMD_BIT_SELF_TEST) {
+            s->op_self_test = OP_RUN;
+            qemu_bh_schedule(s->self_test_bh);
+        }
+        break;
+
+    case RNGC_CONTROL:
+        /*
+         * The CTL_ACC and VERIF_MODE bits are not supported yet.
+         * We ignore them if they're set by the caller.
+         */
+
+        if (value & RNGC_CTRL_BIT_MASK_ERR) {
+            s->mask |= RNGC_CTRL_BIT_MASK_ERR;
+        } else {
+            s->mask &= ~RNGC_CTRL_BIT_MASK_ERR;
+        }
+
+        if (value & RNGC_CTRL_BIT_MASK_DONE) {
+            s->mask |= RNGC_CTRL_BIT_MASK_DONE;
+        } else {
+            s->mask &= ~RNGC_CTRL_BIT_MASK_DONE;
+        }
+
+        if (value & RNGC_CTRL_BIT_AUTO_SEED) {
+            s->auto_seed = true;
+        } else {
+            s->auto_seed = false;
+        }
+        break;
+    }
+}
+
+static const MemoryRegionOps imx_rngc_ops = {
+    .read  = imx_rngc_read,
+    .write = imx_rngc_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static void imx_rngc_self_test(void *opaque)
+{
+    IMXRNGCState *s = IMX_RNGC(opaque);
+
+    s->op_self_test = OP_DONE;
+    if (!(s->mask & RNGC_CTRL_BIT_MASK_DONE)) {
+        qemu_irq_raise(s->irq);
+    }
+}
+
+static void imx_rngc_seed(void *opaque)
+{
+    IMXRNGCState *s = IMX_RNGC(opaque);
+
+    s->op_seed = OP_DONE;
+    if (!(s->mask & RNGC_CTRL_BIT_MASK_DONE)) {
+        qemu_irq_raise(s->irq);
+    }
+}
+
+static void imx_rngc_realize(DeviceState *dev, Error **errp)
+{
+    IMXRNGCState *s = IMX_RNGC(dev);
+    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &imx_rngc_ops, s,
+                          TYPE_IMX_RNGC, 0x1000);
+    sysbus_init_mmio(sbd, &s->iomem);
+
+    sysbus_init_irq(sbd, &s->irq);
+    s->self_test_bh = qemu_bh_new(imx_rngc_self_test, s);
+    s->seed_bh = qemu_bh_new(imx_rngc_seed, s);
+}
+
+static void imx_rngc_reset(DeviceState *dev)
+{
+    IMXRNGCState *s = IMX_RNGC(dev);
+
+    imx_rngc_do_reset(s);
+}
+
+static const VMStateDescription vmstate_imx_rngc = {
+    .name = RNGC_NAME,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(op_self_test, IMXRNGCState),
+        VMSTATE_UINT8(op_seed, IMXRNGCState),
+        VMSTATE_UINT8(mask, IMXRNGCState),
+        VMSTATE_BOOL(auto_seed, IMXRNGCState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void imx_rngc_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = imx_rngc_realize;
+    dc->reset = imx_rngc_reset;
+    dc->desc = RNGC_NAME,
+    dc->vmsd = &vmstate_imx_rngc;
+}
+
+static const TypeInfo imx_rngc_info = {
+    .name          = TYPE_IMX_RNGC,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(IMXRNGCState),
+    .class_init    = imx_rngc_class_init,
+};
+
+static void imx_rngc_register_types(void)
+{
+    type_register_static(&imx_rngc_info);
+}
+
+type_init(imx_rngc_register_types)
diff --git a/include/hw/arm/fsl-imx25.h b/include/hw/arm/fsl-imx25.h
index 241efb52ae..1c86bb55fb 100644
--- a/include/hw/arm/fsl-imx25.h
+++ b/include/hw/arm/fsl-imx25.h
@@ -24,6 +24,7 @@
 #include "hw/timer/imx_gpt.h"
 #include "hw/timer/imx_epit.h"
 #include "hw/net/imx_fec.h"
+#include "hw/misc/imx_rngc.h"
 #include "hw/i2c/imx_i2c.h"
 #include "hw/gpio/imx_gpio.h"
 #include "exec/memory.h"
@@ -50,6 +51,7 @@ typedef struct FslIMX25State {
     IMXGPTState    gpt[FSL_IMX25_NUM_GPTS];
     IMXEPITState   epit[FSL_IMX25_NUM_EPITS];
     IMXFECState    fec;
+    IMXRNGCState   rngc;
     IMXI2CState    i2c[FSL_IMX25_NUM_I2CS];
     IMXGPIOState   gpio[FSL_IMX25_NUM_GPIOS];
     MemoryRegion   rom[2];
@@ -211,6 +213,8 @@ typedef struct FslIMX25State {
 #define FSL_IMX25_GPIO4_SIZE    0x4000
 #define FSL_IMX25_GPIO3_ADDR    0x53FA4000
 #define FSL_IMX25_GPIO3_SIZE    0x4000
+#define FSL_IMX25_RNGC_ADDR     0x53FB0000
+#define FSL_IMX25_RNGC_SIZE     0x4000
 #define FSL_IMX25_GPIO1_ADDR    0x53FCC000
 #define FSL_IMX25_GPIO1_SIZE    0x4000
 #define FSL_IMX25_GPIO2_ADDR    0x53FD0000
@@ -238,6 +242,7 @@ typedef struct FslIMX25State {
 #define FSL_IMX25_EPIT1_IRQ     28
 #define FSL_IMX25_EPIT2_IRQ     27
 #define FSL_IMX25_FEC_IRQ       57
+#define FSL_IMX25_RNGC_IRQ      22
 #define FSL_IMX25_I2C1_IRQ      3
 #define FSL_IMX25_I2C2_IRQ      4
 #define FSL_IMX25_I2C3_IRQ      10
diff --git a/include/hw/misc/imx_rngc.h b/include/hw/misc/imx_rngc.h
new file mode 100644
index 0000000000..f0d2b44d4f
--- /dev/null
+++ b/include/hw/misc/imx_rngc.h
@@ -0,0 +1,35 @@
+/*
+ * Freescale i.MX RNGC emulation
+ *
+ * Copyright (C) 2020 Martin Kaiser <martin@kaiser.cx>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef IMX_RNGC_H
+#define IMX_RNGC_H
+
+#include "hw/sysbus.h"
+
+#define TYPE_IMX_RNGC "imx.rngc"
+#define IMX_RNGC(obj) OBJECT_CHECK(IMXRNGCState, (obj), TYPE_IMX_RNGC)
+
+typedef struct IMXRNGCState {
+    /*< private >*/
+    SysBusDevice parent_obj;
+
+    /*< public >*/
+    MemoryRegion  iomem;
+
+    uint8_t op_self_test;
+    uint8_t op_seed;
+    uint8_t mask;
+    bool    auto_seed;
+
+    QEMUBH *self_test_bh;
+    QEMUBH *seed_bh;
+    qemu_irq irq;
+} IMXRNGCState;
+
+#endif /* IMX_RNGC_H */