Kernel: Add basic PCI and very basic rtl8139 support

4 files changed, 110 insertions, 0 deletions

diff --git a/drivers/pci.c b/drivers/pci.c
new file mode 100644
index 0000000..a71cc9a
--- /dev/null
+++ b/drivers/pci.c
@@ -0,0 +1,45 @@
+#include <cpu/io.h>
+#include <drivers/pci.h>
+#include <stdio.h>
+
+#define CONFIG_ADDRESS 0xCF8
+#define CONFIG_DATA 0xCFC
+
+uint32_t pci_config_read32(const struct PCI_DEVICE *device, uint8_t func,
+                           uint8_t offset) {
+  uint32_t address;
+  uint32_t lbus = (uint32_t)device->bus;
+  uint32_t lslot = (uint32_t)device->slot;
+  uint32_t lfunc = (uint32_t)func;
+
+  // Create configuration address as per Figure 1
+  address = (uint32_t)((lbus << 16) | (lslot << 11) | (lfunc << 8) |
+                       (offset & 0xFC) | ((uint32_t)0x80000000));
+
+  // Write out the address
+  outl(CONFIG_ADDRESS, address);
+  return inl(CONFIG_DATA);
+}
+
+int pci_populate_device_struct(uint16_t vendor, uint16_t device,
+                               struct PCI_DEVICE *pci_device) {
+  pci_device->vendor = vendor;
+  pci_device->device = device;
+
+  for (int bus = 0; bus < 256; bus++) {
+    for (int slot = 0; slot < 256; slot++) {
+      struct PCI_DEVICE tmp;
+      tmp.bus = bus;
+      tmp.slot = slot;
+      uint32_t device_vendor = pci_config_read32(&tmp, 0, 0);
+      if (vendor != (device_vendor & 0xFFFF))
+        continue;
+      if (device != (device_vendor >> 16))
+        continue;
+      pci_device->bus = bus;
+      pci_device->slot = slot;
+      return 1;
+    }
+  }
+  return 0;
+}
diff --git a/drivers/pci.h b/drivers/pci.h
new file mode 100644
index 0000000..6a8bc1c
--- /dev/null
+++ b/drivers/pci.h
@@ -0,0 +1,14 @@
+#include <stdint.h>
+
+struct PCI_DEVICE {
+  uint16_t vendor;
+  uint16_t device;
+  uint8_t bus;
+  uint8_t slot;
+};
+
+uint32_t pci_config_read32(const struct PCI_DEVICE *device, uint8_t func,
+                           uint8_t offset);
+
+int pci_populate_device_struct(uint16_t vendor, uint16_t device,
+                               struct PCI_DEVICE *pci_device);
diff --git a/drivers/rtl8139.c b/drivers/rtl8139.c
new file mode 100644
index 0000000..44212e0
--- /dev/null
+++ b/drivers/rtl8139.c
@@ -0,0 +1,50 @@
+#include <assert.h>
+#include <cpu/io.h>
+#include <drivers/pci.h>
+#include <drivers/rtl8139.h>
+#include <mmu.h>
+
+#define RBSTART 0x30
+#define CMD 0x37
+#define IMR 0x3C
+
+struct PCI_DEVICE rtl8139;
+uint8_t device_buffer[8192 + 16];
+
+void rtl8139_init(void) {
+  if (!pci_populate_device_struct(0x10EC, 0x8139, &rtl8139)) {
+    kprintf("RTL8139 not found :(\n");
+    return;
+  }
+  kprintf("RTL8139 found at bus: %x slot: %x\n", rtl8139.bus, rtl8139.slot);
+
+  uint8_t header_type = (pci_config_read32(&rtl8139, 0, 0xC) >> 16) & 0xFF;
+  assert(0 == header_type);
+
+  uint32_t base_address = pci_config_read32(&rtl8139, 0, 0x10);
+  uint8_t interrupt_line = pci_config_read32(&rtl8139, 0, 0x3C);
+  kprintf("interrupt_line: %x\n", interrupt_line);
+
+  // Turning on the device
+  outb(base_address + 0x52, 0x0);
+
+  // Reset the device and clear the RX and TX buffers
+  outb(base_address + CMD, 0x10);
+  for (; 0 != (inb(base_address + CMD) & 0x10);)
+    ;
+
+  // Setupt the recieve buffer
+  uint32_t rx_buffer = (uint32_t)virtual_to_physical(device_buffer, NULL);
+  outl(base_address + RBSTART, rx_buffer);
+
+  // Set IMR + ISR
+  outw(base_address + IMR, 0x0005); // Sets the TOK and ROK bits high
+
+  // Configure the recieve buffer
+  outl(base_address + 0x44,
+       0xf | (1 << 7)); // (1 << 7) is the WRAP bit, 0xf is AB+AM+APM+AAP
+
+  // Enable recieve and transmitter
+  outb(base_address + 0x37, 0x0C); // Sets the RE and TE bits high
+  asm("sti");
+}
diff --git a/drivers/rtl8139.h b/drivers/rtl8139.h
new file mode 100644
index 0000000..1f3d84e
--- /dev/null
+++ b/drivers/rtl8139.h
@@ -0,0 +1 @@
+void rtl8139_init(void);