From 11b4d6a2bcd7b9c18b81b38388b7d7c851fb9da3 Mon Sep 17 00:00:00 2001
From: kamkow1 <kamkow256@gmail.com>
Date: Sat, 29 Nov 2025 23:54:12 +0100
Subject: [PATCH] QEMU PCI testdev driver

---
 kernel/Makefile                   |  1 +
 kernel/pci/pci.c                  |  2 ++
 kernel/pci/qemu/testdev/testdev.c | 36 +++++++++++++++++++++++++++++++
 kernel/pci/qemu/testdev/testdev.h |  6 ++++++
 4 files changed, 45 insertions(+)
 create mode 100644 kernel/pci/qemu/testdev/testdev.c
 create mode 100644 kernel/pci/qemu/testdev/testdev.h

diff --git a/kernel/Makefile b/kernel/Makefile
index 02ceafe..0e00004 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -71,6 +71,7 @@ SRCFILES += $(call GRABSRC, \
 							pci \
 							pci/ata \
 							pci/serial \
+							pci/qemu/testdev \
 							cjob \
             )
 
diff --git a/kernel/pci/pci.c b/kernel/pci/pci.c
index 790d680..8905abe 100644
--- a/kernel/pci/pci.c
+++ b/kernel/pci/pci.c
@@ -3,6 +3,7 @@
 #include "pci/pci.h"
 #include "pci/ata/ata.h"
 #include "pci/serial/serial.h"
+#include "pci/qemu/testdev/testdev.h"
 #include "io/io.h"
 #include "std/string.h"
 #include "util/util.h"
@@ -194,6 +195,7 @@ PciDev pci_getdev(uint16_t vendorid, uint16_t deviceid, int devtype) {
 PciInitFn PCI_INIT_ARRAY[PCI_INIT_ARRAY_MAX] = {
   &pci_ata_init,
   &pci_serial_init,
+  &pci_qemu_testdev_init,
 };
 
 void pci_init_devs(void) {
diff --git a/kernel/pci/qemu/testdev/testdev.c b/kernel/pci/qemu/testdev/testdev.c
new file mode 100644
index 0000000..fcd8a47
--- /dev/null
+++ b/kernel/pci/qemu/testdev/testdev.c
@@ -0,0 +1,36 @@
+#include <stdint.h>
+#include <stddef.h>
+#include "pci/qemu/testdev/testdev.h"
+#include "pci/pci.h"
+#include "vmm/vmm.h"
+#include "bootinfo/bootinfo.h"
+#include "std/string.h"
+#include "kprintf.h"
+
+// REF: https://www.qemu.org/docs/master/specs/pci-testdev.html
+
+#define TAG "qemu-testdev"
+
+typedef struct {
+  PciBar bar0, bar1, bar2;
+} QemuTestDev;
+
+QemuTestDev PCI_QEMU_TESTDEV;
+
+void pci_qemu_testdev_init(void) {
+  PciDev dev = pci_getdev(0x1B36, 0x0005, -1);
+  if (!dev.bits) {
+    return;
+  }
+
+  uint8_t progif = pci_read8(dev, PCI_PROGIF);
+  LOG("pci/"TAG, "progif=0x%02x\n", progif);
+
+  pci_getbar(dev, &PCI_QEMU_TESTDEV.bar0, PCI_BAR0);
+  pci_getbar(dev, &PCI_QEMU_TESTDEV.bar1, PCI_BAR1);
+  pci_getbar(dev, &PCI_QEMU_TESTDEV.bar2, PCI_BAR2);
+
+  PCI_LOG_BAR(TAG, PCI_QEMU_TESTDEV.bar0, 0);
+  PCI_LOG_BAR(TAG, PCI_QEMU_TESTDEV.bar1, 1);
+  PCI_LOG_BAR(TAG, PCI_QEMU_TESTDEV.bar2, 2);
+}
diff --git a/kernel/pci/qemu/testdev/testdev.h b/kernel/pci/qemu/testdev/testdev.h
new file mode 100644
index 0000000..d0febb4
--- /dev/null
+++ b/kernel/pci/qemu/testdev/testdev.h
@@ -0,0 +1,6 @@
+#ifndef PCI_QEMU_TESTDEV_TESTDEV_H_
+#define PCI_QEMU_TESTDEV_TESTDEV_H_
+
+void pci_qemu_testdev_init(void);
+
+#endif // PCI_QEMU_TESTDEV_TESTDEV_H_