[sw] Add HW_ID platform check

Update the test framework smoketest to read the HW_ID register,
validate it against known values, and fail on an unrecognised ID.

Signed-off-by: martin-velay <mvelay@lowrisc.org>

Author: martin-velay

sw/device/lib/hal/mocha.c

@@ -14,6 +14,7 @@
 static const uintptr_t rom_base = 0x80000ul;
 static const uintptr_t mailbox_base = 0x20010000ul;
 static const uintptr_t dv_test_status_base = 0x20020000ul;
+static const uintptr_t dv_hw_id_base = 0x20020008ul;
 static const uintptr_t ethernet_base = 0x30000000ul;
 static const uintptr_t gpio_base = 0x40000000ul;
 static const uintptr_t clkmgr_base = 0x40020000ul;
@@ -201,3 +202,12 @@ void *mocha_system_dv_test_status(void)
     return (void *)dv_test_status_base;
 #endif /* defined(__riscv_zcherihybrid) */
 }
+
+void *mocha_system_dv_hw_id(void)
+{
+#if defined(__riscv_zcherihybrid)
+    return create_mmio_capability(dv_hw_id_base, 0x4u);
+#else /* !defined(__riscv_zcherihybrid) */
+    return (void *)dv_hw_id_base;
+#endif /* defined(__riscv_zcherihybrid) */
+}

sw/device/lib/hal/mocha.h

@@ -52,3 +52,10 @@ plic_t mocha_system_plic(void);
 void *mocha_system_dram(void);
 
 void *mocha_system_dv_test_status(void);
+void *mocha_system_dv_hw_id(void);
+
+typedef enum : uint32_t {
+    HW_ID_FPGA_GENESYS2 = 0x0000000Au,
+    HW_ID_SIM_VERILATOR = 0x0000001Au,
+    HW_ID_SIM_UVM = 0x0000002Au,
+} dv_hw_platform_t;

sw/device/tests/test_framework/smoketest.c

@@ -2,11 +2,28 @@
 // Licensed under the Apache License, Version 2.0, see LICENSE for details.
 // SPDX-License-Identifier: Apache-2.0
 
-#include "hal/uart.h"
+#include "hal/mmio.h"
+#include "hal/mocha.h"
 #include <stdbool.h>
 
 bool test_main(uart_t console)
 {
+    dv_hw_platform_t hw_id = (dv_hw_platform_t)DEV_READ(mocha_system_dv_hw_id());
+
     uart_puts(console, "Test framework smoketest\n");
-    return true;
+
+    switch (hw_id) {
+    case HW_ID_FPGA_GENESYS2:
+        uart_puts(console, "Platform: FpgaGenesys2\n");
+        return true;
+    case HW_ID_SIM_VERILATOR:
+        uart_puts(console, "Platform: SimVerilator\n");
+        return true;
+    case HW_ID_SIM_UVM:
+        uart_puts(console, "Platform: SimUvm\n");
+        return true;
+    default:
+        uart_puts(console, "Unknown HW_ID\n");
+        return false;
+    }
 }