ast2600: Add Secure Boot Controller model

Just a stub that indicates the system has booted in secure boot mode.
Used for testing the driver:

 https://lore.kernel.org/all/20211019080608.283324-1-joel@jms.id.au/

Signed-off-by: Joel Stanley <joel@jms.id.au>
[ clg: - Fixed typo
       - Adjusted Copyright dates ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>

3 files changed, 151 insertions, 0 deletions

diff --git a/hw/arm/aspeed_ast2600.c b/hw/arm/aspeed_ast2600.c
index 12f6edc081..21cd3342c5 100644
--- a/hw/arm/aspeed_ast2600.c
+++ b/hw/arm/aspeed_ast2600.c
@@ -47,6 +47,7 @@ static const hwaddr aspeed_soc_ast2600_memmap[] = {
     [ASPEED_DEV_XDMA]      = 0x1E6E7000,
     [ASPEED_DEV_ADC]       = 0x1E6E9000,
     [ASPEED_DEV_DP]        = 0x1E6EB000,
+    [ASPEED_DEV_SBC]       = 0x1E6F2000,
     [ASPEED_DEV_VIDEO]     = 0x1E700000,
     [ASPEED_DEV_SDHCI]     = 0x1E740000,
     [ASPEED_DEV_EMMC]      = 0x1E750000,
@@ -227,6 +228,8 @@ static void aspeed_soc_ast2600_init(Object *obj)
     object_initialize_child(obj, "hace", &s->hace, typename);
 
     object_initialize_child(obj, "i3c", &s->i3c, TYPE_ASPEED_I3C);
+
+    object_initialize_child(obj, "sbc", &s->sbc, TYPE_ASPEED_SBC);
 }
 
 /*
@@ -539,6 +542,12 @@ static void aspeed_soc_ast2600_realize(DeviceState *dev, Error **errp)
         /* The AST2600 I3C controller has one IRQ per bus. */
         sysbus_connect_irq(SYS_BUS_DEVICE(&s->i3c.devices[i]), 0, irq);
     }
+
+    /* Secure Boot Controller */
+    if (!sysbus_realize(SYS_BUS_DEVICE(&s->sbc), errp)) {
+        return;
+    }
+    sysbus_mmio_map(SYS_BUS_DEVICE(&s->sbc), 0, sc->memmap[ASPEED_DEV_SBC]);
 }
 
 static void aspeed_soc_ast2600_class_init(ObjectClass *oc, void *data)
diff --git a/hw/misc/aspeed_sbc.c b/hw/misc/aspeed_sbc.c
new file mode 100644
index 0000000000..40f2a8c631
--- /dev/null
+++ b/hw/misc/aspeed_sbc.c
@@ -0,0 +1,141 @@
+/*
+ * ASPEED Secure Boot Controller
+ *
+ * Copyright (C) 2021-2022 IBM Corp.
+ *
+ * Joel Stanley <joel@jms.id.au>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qemu/error-report.h"
+#include "hw/misc/aspeed_sbc.h"
+#include "qapi/error.h"
+#include "migration/vmstate.h"
+
+#define R_PROT          (0x000 / 4)
+#define R_STATUS        (0x014 / 4)
+
+static uint64_t aspeed_sbc_read(void *opaque, hwaddr addr, unsigned int size)
+{
+    AspeedSBCState *s = ASPEED_SBC(opaque);
+
+    addr >>= 2;
+
+    if (addr >= ASPEED_SBC_NR_REGS) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Out-of-bounds read at offset 0x%" HWADDR_PRIx "\n",
+                      __func__, addr << 2);
+        return 0;
+    }
+
+    return s->regs[addr];
+}
+
+static void aspeed_sbc_write(void *opaque, hwaddr addr, uint64_t data,
+                              unsigned int size)
+{
+    AspeedSBCState *s = ASPEED_SBC(opaque);
+
+    addr >>= 2;
+
+    if (addr >= ASPEED_SBC_NR_REGS) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Out-of-bounds write at offset 0x%" HWADDR_PRIx "\n",
+                      __func__, addr << 2);
+        return;
+    }
+
+    switch (addr) {
+    case R_STATUS:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: write to read only register 0x%" HWADDR_PRIx "\n",
+                      __func__, addr << 2);
+        return;
+    default:
+        break;
+    }
+
+    s->regs[addr] = data;
+}
+
+static const MemoryRegionOps aspeed_sbc_ops = {
+    .read = aspeed_sbc_read,
+    .write = aspeed_sbc_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .valid = {
+        .min_access_size = 1,
+        .max_access_size = 4,
+    },
+};
+
+static void aspeed_sbc_reset(DeviceState *dev)
+{
+    struct AspeedSBCState *s = ASPEED_SBC(dev);
+
+    memset(s->regs, 0, sizeof(s->regs));
+
+    /* Set secure boot enabled, and boot from emmc/spi */
+    s->regs[R_STATUS] = 1 << 6 | 1 << 5;
+}
+
+static void aspeed_sbc_realize(DeviceState *dev, Error **errp)
+{
+    AspeedSBCState *s = ASPEED_SBC(dev);
+    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_sbc_ops, s,
+            TYPE_ASPEED_SBC, 0x1000);
+
+    sysbus_init_mmio(sbd, &s->iomem);
+}
+
+static const VMStateDescription vmstate_aspeed_sbc = {
+    .name = TYPE_ASPEED_SBC,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(regs, AspeedSBCState, ASPEED_SBC_NR_REGS),
+        VMSTATE_END_OF_LIST(),
+    }
+};
+
+static void aspeed_sbc_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = aspeed_sbc_realize;
+    dc->reset = aspeed_sbc_reset;
+    dc->vmsd = &vmstate_aspeed_sbc;
+}
+
+static const TypeInfo aspeed_sbc_info = {
+    .name = TYPE_ASPEED_SBC,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(AspeedSBCState),
+    .class_init = aspeed_sbc_class_init,
+    .class_size = sizeof(AspeedSBCClass)
+};
+
+static void aspeed_ast2600_sbc_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->desc = "AST2600 Secure Boot Controller";
+}
+
+static const TypeInfo aspeed_ast2600_sbc_info = {
+    .name = TYPE_ASPEED_AST2600_SBC,
+    .parent = TYPE_ASPEED_SBC,
+    .class_init = aspeed_ast2600_sbc_class_init,
+};
+
+static void aspeed_sbc_register_types(void)
+{
+    type_register_static(&aspeed_ast2600_sbc_info);
+    type_register_static(&aspeed_sbc_info);
+}
+
+type_init(aspeed_sbc_register_types);
diff --git a/hw/misc/meson.build b/hw/misc/meson.build
index 6dcbe044f3..645585371a 100644
--- a/hw/misc/meson.build
+++ b/hw/misc/meson.build
@@ -111,6 +111,7 @@ softmmu_ss.add(when: 'CONFIG_ASPEED_SOC', if_true: files(
   'aspeed_i3c.c',
   'aspeed_lpc.c',
   'aspeed_scu.c',
+  'aspeed_sbc.c',
   'aspeed_sdmc.c',
   'aspeed_xdma.c'))