1 files changed, 119 insertions, 0 deletions
diff --git a/src/loader/pci.c b/src/loader/pci.c
new file mode 100644
index 0000000..e2c485d
--- /dev/null
+++ b/src/loader/pci.c
@@ -0,0 +1,119 @@
+// MIT License, Copyright (c) 2021 Marvin Borner
+
+#include <cpu.h>
+#include <ide.h>
+#include <log.h>
+#include <pci.h>
+
+// Generate device ID
+#define PCI_DEVICE(bus, slot, func) ((u32)((bus << 16) | (slot << 8) | func))
+
+// Extract data from device ID
+#define PCI_BUS(device) ((u8)(device >> 16))
+#define PCI_SLOT(device) ((u8)(device >> 8))
+#define PCI_FUNC(device) ((u8)(device))
+
+// Calculate address
+#define PCI_ADDR(device, field)                                                                    \
+	(0x80000000 | (u32)(PCI_BUS(device) << 16) | (u32)(PCI_SLOT(device) << 11) |               \
+	 (u32)(PCI_FUNC(device) << 8) | ((field)&0xfc))
+
+// Read pci device type
+#define PCI_TYPE(device)                                                                           \
+	((u32)((pci_read(device, PCI_CLASS, 1) << 16) | (pci_read(device, PCI_SUBCLASS, 1) << 8) | \
+	       pci_read(device, PCI_PROG_IF, 1)))
+
+static u32 pci_read(u32 device, u8 field, u32 size)
+{
+	outl(PCI_ADDR_PORT, PCI_ADDR(device, field));
+
+	if (size == 4) {
+		u32 t = inl(PCI_VALUE_PORT);
+		return t;
+	} else if (size == 2) {
+		u16 t = inw((u16)(PCI_VALUE_PORT + (field & 2)));
+		return t;
+	} else if (size == 1) {
+		u8 t = inb((u16)(PCI_VALUE_PORT + (field & 3)));
+		return t;
+	}
+
+	return PCI_NONE;
+}
+
+/**
+ * PCI scanning
+ */
+
+static void pci_print(u16 vendor_id, u16 device_id, u32 type_id)
+{
+	const char *vendor = "unknown";
+	const char *device = "unknown";
+	const char *class = "unknown";
+
+	for (u16 i = 0; i < COUNT(pci_vendors); i++)
+		if (pci_vendors[i].id == vendor_id)
+			vendor = pci_vendors[i].name;
+
+	for (u16 i = 0; i < COUNT(pci_devices); i++)
+		if (pci_devices[i].vendor_id == vendor_id && pci_devices[i].device_id == device_id)
+			device = pci_devices[i].name;
+
+	for (u16 i = 0; i < COUNT(pci_types); i++)
+		if (pci_types[i].id == type_id)
+			class = pci_types[i].name;
+
+	log("[PCI] %s: %s - %s\n", vendor, device, class);
+}
+
+static void pci_probe_bus(u8 bus);
+static void pci_probe_func(u8 bus, u8 slot, u8 func)
+{
+	u32 device = PCI_DEVICE(bus, slot, func);
+
+	u16 vendor_id = pci_read(device, PCI_VENDOR_ID, 2);
+	u16 device_id = pci_read(device, PCI_DEVICE_ID, 2);
+	u32 type_id = PCI_TYPE(device);
+	pci_print(vendor_id, device_id, type_id);
+
+	if (PCI_TYPE(device) == PCI_TYPE_BRIDGE)
+		pci_probe_bus(pci_read(device, PCI_SECONDARY_BUS, 1));
+
+	if (PCI_IDE(vendor_id, device_id))
+		ata_install();
+}
+
+static void pci_probe_slot(u8 bus, u8 slot)
+{
+	u32 device = PCI_DEVICE(bus, slot, 0);
+	if (pci_read(device, PCI_VENDOR_ID, 2) == PCI_NONE)
+		return;
+
+	// Scan first func
+	pci_probe_func(bus, slot, 0);
+
+	if (!pci_read(device, PCI_HEADER_TYPE, 1))
+		return;
+
+	// Scan rest
+	for (u8 func = 1; func < 8; func++) {
+		device = PCI_DEVICE(bus, slot, func);
+		if (pci_read(device, PCI_VENDOR_ID, 2) != PCI_NONE)
+			pci_probe_func(bus, slot, func);
+	}
+}
+
+static void pci_probe_bus(u8 bus)
+{
+	for (u8 slot = 0; slot < 32; slot++)
+		pci_probe_slot(bus, slot);
+}
+
+void pci_probe(void)
+{
+	for (u8 func = 0; func < 8; func++) {
+		u32 device = PCI_DEVICE(0, 0, func);
+		if (pci_read(device, PCI_VENDOR_ID, 2) != PCI_NONE)
+			pci_probe_bus(func);
+	}
+}