boards: add initial sencha board support

This defines a board with the I2S, ML_TOP, and MAILBOX peripherals.
.5M heap with software revocation.

Change-Id: I59a4d32ca00374fe86c022dd52e4a4792f57161a

sdk/boards/sencha.json

diff --git a/sdk/boards/sencha.json b/sdk/boards/sencha.json
new file mode 100644
index 0000000..3809fde
--- /dev/null
+++ b/sdk/boards/sencha.json
@@ -0,0 +1,93 @@
+{
+    "devices": {
+        "clint": {
+            "start"  : 0x2000000,
+            "length" : 0x10000
+        },
+        "plic": {
+            "start"  : 0x60000000,
+            "length" : 0x400000
+        },
+        "uart": {
+            "start": 0x10000000,
+            "end":   0x10000100
+        },
+        "i2s": {
+            "start": 0x54100000,
+            "length": 0x40
+        },
+        "ml_top_core": {
+            "start": 0x5C000000,
+            "length": 0x40
+        },
+        "ml_top_dmem": {
+            "start": 0x5A000000,
+            "length": 0x400000
+        },
+        "mailbox_smc": {
+            "start": 0x540F1000,
+            "length": 0x40
+        },
+        "shadow" : {
+            "start": 0x83000000,
+            "end":   0x83010000
+        }
+    },
+    "instruction_memory": {
+        "start": 0x80000000,
+        "end": 0x80400000
+    },
+    "heap": {
+        "start": 0x80380000,
+        "end":   0x80400000
+    },
+    "interrupts": [
+        {
+            "name": "UARTInterrupt",
+            "number": 2,
+            "priority": 3,
+            "edge_triggered": true
+        },
+        {
+            "name": "I2sRxWatermarkInterrupt",
+            "number": 3,
+            "priority": 3
+        },
+        {
+            "name": "I2sTxWatermarkInterrupt",
+            "number": 4,
+            "priority": 3
+        },
+        {
+            "name": "I2sTxEmptyInterrupt",
+            "number": 5,
+            "priority": 3
+        },
+        {
+            "name": "MlTopFinishInterrupt",
+            "number": 6,
+            "priority": 3
+        },
+        {
+            "name": "MlTopFaultInterrupt",
+            "number": 7,
+            "priority": 3
+        },
+        {
+            "name": "MailboxRtInterrupt",
+            "number": 8,
+            "priority": 3
+        }
+    ],
+    "defines" : [ "SENCHA" ],
+    "driver_includes" : [
+        "${sdk}/include/platform/sencha",
+        "${sdk}/include/platform/generic-riscv"
+    ],
+    "timer_hz" : 2000,
+    "tickrate_hz" : 10,
+    "revoker" : "software",
+    "stack_high_water_mark" : true,
+    "simulator" : "cheriot_sim",
+    "simulation": true
+}

sdk/include/platform/sencha/platform-i2s.hh

diff --git a/sdk/include/platform/sencha/platform-i2s.hh b/sdk/include/platform/sencha/platform-i2s.hh
new file mode 100644
index 0000000..1bc3540
--- /dev/null
+++ b/sdk/include/platform/sencha/platform-i2s.hh
@@ -0,0 +1,17 @@
+#pragma once
+#include <compartment-macros.h>
+#include <interrupt.h>
+#include <riscvreg.h>
+
+DECLARE_AND_DEFINE_INTERRUPT_CAPABILITY(i2sRxWatermarkInterruptCapability,
+                                        InterruptName::I2sRxWatermarkInterrupt,
+                                        true,
+                                        true)
+DECLARE_AND_DEFINE_INTERRUPT_CAPABILITY(i2sTxWatermarkInterruptCapability,
+                                        InterruptName::I2sTxWatermarkInterrupt,
+                                        true,
+                                        true)
+DECLARE_AND_DEFINE_INTERRUPT_CAPABILITY(i2sTxEmptyInterruptCapability,
+                                        InterruptName::I2sTxEmptyInterrupt,
+                                        true,
+                                        true)

sdk/include/platform/sencha/platform-mailbox.hh

diff --git a/sdk/include/platform/sencha/platform-mailbox.hh b/sdk/include/platform/sencha/platform-mailbox.hh
new file mode 100644
index 0000000..fb172e5
--- /dev/null
+++ b/sdk/include/platform/sencha/platform-mailbox.hh
@@ -0,0 +1,9 @@
+#pragma once
+#include <compartment-macros.h>
+#include <interrupt.h>
+#include <riscvreg.h>
+
+DECLARE_AND_DEFINE_INTERRUPT_CAPABILITY(mailboxRtInterruptCapability,
+                                        InterruptName::MailboxRtInterrupt,
+                                        true,
+                                        true)

sdk/include/platform/sencha/platform-ml_top.hh

diff --git a/sdk/include/platform/sencha/platform-ml_top.hh b/sdk/include/platform/sencha/platform-ml_top.hh
new file mode 100644
index 0000000..cb7af3b
--- /dev/null
+++ b/sdk/include/platform/sencha/platform-ml_top.hh
@@ -0,0 +1,13 @@
+#pragma once
+#include <compartment-macros.h>
+#include <interrupt.h>
+#include <riscvreg.h>
+
+DECLARE_AND_DEFINE_INTERRUPT_CAPABILITY(mlTopFinishInterruptCapability,
+                                        InterruptName::MlTopFinishInterrupt,
+                                        true,
+                                        true)
+DECLARE_AND_DEFINE_INTERRUPT_CAPABILITY(mlTopFaultInterruptCapability,
+                                        InterruptName::MlTopFaultInterrupt,
+                                        true,
+                                        true)