From e90b72ec3082588b296956730bd2930cf8d5d671 Mon Sep 17 00:00:00 2001
From: Richard Qin <richard.qin.x@gmail.com>
Date: Fri, 10 Jul 2026 11:31:46 +0800
Subject: refactor: promote new architecture to repository root

Archive the deprecated implementation under lume-legacy, make the new kernel the default root-level build, and update repository entry points without changing kernel behavior.
---
 lume-legacy/src/drivers/plic.cc | 77 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 lume-legacy/src/drivers/plic.cc

(limited to 'lume-legacy/src/drivers/plic.cc')

diff --git a/lume-legacy/src/drivers/plic.cc b/lume-legacy/src/drivers/plic.cc
new file mode 100644
index 0000000..a975c44
--- /dev/null
+++ b/lume-legacy/src/drivers/plic.cc
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2026 Richard Qin
+ */
+#include "common/types.h"
+#include "kernel/riscv.h"
+#include "drivers/plic.h"
+#include "drivers/uart.h"
+#include "kernel/fdt.h"
+
+// Helper Macros — all relative to PLIC base from FDT
+#define PLIC_BASE      (g_devices.plic.base_addr)
+#define PLIC_PRIORITY  (PLIC_BASE + 0x0)
+#define PLIC_PENDING   (PLIC_BASE + 0x1000)
+
+#define PLIC_SENABLE_ADDR(hart) (PLIC_BASE + 0x2080 + (hart) * 0x100)
+#define PLIC_STHRESHOLD_ADDR(hart) (PLIC_BASE + 0x201000 + (hart) * 0x2000)
+#define PLIC_SCLAIM_ADDR(hart) (PLIC_BASE + 0x201004 + (hart) * 0x2000)
+
+// Helper for Volatile Access
+static inline volatile uint32 *REG32(uint64 addr)
+{
+    return reinterpret_cast<volatile uint32 *>(addr);
+}
+
+namespace PLIC
+{
+    void init()
+    {
+        // Set priority for UART IRQ
+        if (g_devices.uart.irq > 0)
+            *REG32(PLIC_PRIORITY + g_devices.uart.irq * 4) = 1;
+
+        // Set priority for all VirtIO IRQs
+        for (int i = 0; i < g_devices.virtio_count; i++)
+        {
+            if (g_devices.virtio[i].irq > 0)
+                *REG32(PLIC_PRIORITY + g_devices.virtio[i].irq * 4) = 1;
+        }
+    }
+
+    void inithart()
+    {
+        int hart = static_cast<int>(r_tp());
+
+        // Build enable bitmask from discovered devices
+        uint32 enable = 0;
+
+        if (g_devices.uart.irq > 0 && g_devices.uart.irq < 32)
+            enable |= (1 << g_devices.uart.irq);
+
+        for (int i = 0; i < g_devices.virtio_count; i++)
+        {
+            if (g_devices.virtio[i].irq > 0 && g_devices.virtio[i].irq < 32)
+                enable |= (1 << g_devices.virtio[i].irq);
+        }
+
+        *REG32(PLIC_SENABLE_ADDR(hart)) = enable;
+
+        // Set Priority Threshold to 0 (Allow all)
+        *REG32(PLIC_STHRESHOLD_ADDR(hart)) = 0;
+
+        Drivers::uart_puts("[PLIC] Hart Init Done.\n");
+    }
+
+    int claim()
+    {
+        int hart = static_cast<int>(r_tp());
+        return *REG32(PLIC_SCLAIM_ADDR(hart));
+    }
+
+    void complete(int irq)
+    {
+        int hart = static_cast<int>(r_tp());
+        *REG32(PLIC_SCLAIM_ADDR(hart)) = static_cast<uint32>(irq);
+    }
+}
\ No newline at end of file
-- 
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