From b9ff206e6bd3f4d67851263a6f2acb5f575cf3b0 Mon Sep 17 00:00:00 2001
From: Richard Qin <richard.qin.x@gmail.com>
Date: Fri, 10 Jul 2026 11:48:04 +0800
Subject: fix: match all FDT compatible strings

Walk the complete NUL-separated compatible property when binding platform devices so the QEMU PLIC probes correctly and UART receive interrupts reach the TTY. Add a boot-time regression assertion for IRQ-chip binding.
---
 drivers/base/platform.cc  | 25 +++++++++++++++++++++----
 test/test_driver_model.cc |  5 +++++
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/base/platform.cc b/drivers/base/platform.cc
index 65ec21e..fae8af6 100644
--- a/drivers/base/platform.cc
+++ b/drivers/base/platform.cc
@@ -51,14 +51,31 @@ static int platform_match(device* dev, device_driver* drv)
     if (pdrv->of_match_table == nullptr || pdev->of_node == nullptr) {
         return 0;
     }
-    const char* node_compat = pdev->of_node->get_prop_string("compatible");
-    if (node_compat == nullptr) {
+    const FdtProperty* compat_prop = pdev->of_node->get_prop("compatible");
+    if (compat_prop == nullptr || compat_prop->value == nullptr ||
+        compat_prop->len == 0) {
         return 0;
     }
+
+    const char* compat_list = static_cast<const char*>(compat_prop->value);
+    const uint32 compat_len = static_cast<uint32>(compat_prop->len);
     for (const of_device_id* id = pdrv->of_match_table;
          id->compatible != nullptr; ++id) {
-        if (strcmp(id->compatible, node_compat) == 0) {
-            return 1;
+        uint32 offset = 0;
+        while (offset < compat_len) {
+            const char* node_compat = compat_list + offset;
+            uint32 remaining = compat_len - offset;
+            uint32 length = 0;
+            while (length < remaining && node_compat[length] != '\0') {
+                ++length;
+            }
+            if (length == remaining) {
+                break;  /* malformed property without a terminating NUL */
+            }
+            if (strcmp(id->compatible, node_compat) == 0) {
+                return 1;
+            }
+            offset += length + 1;
         }
     }
     return 0;
diff --git a/test/test_driver_model.cc b/test/test_driver_model.cc
index 8f105b3..074a84e 100644
--- a/test/test_driver_model.cc
+++ b/test/test_driver_model.cc
@@ -11,6 +11,7 @@
 #include <lume/kref.h>
 #include <lume/kobject.h>
 #include <lume/device.h>
+#include <lume/irq.h>
 
 /* ------------------------------------------------------------------ */
 /*  Test 1: kref get/put + release fires exactly once                  */
@@ -206,4 +207,8 @@ void selftest_driver_model()
     test_kref();
     test_kobject_hierarchy();
     test_bus_bind();
+
+    st_begin("driver model: platform IRQ chip probed");
+    ST_ASSERT(g_irq_manager.get_chip() != nullptr);
+    st_pass();
 }
-- 
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