Meta: Move kernel and userland to their own folders.

This is to allow both the kernel and the userland to share certain
header files and to make the folder structure a bit more clear.

1 files changed, 182 insertions, 0 deletions

diff --git a/kernel/drivers/rtl8139.c b/kernel/drivers/rtl8139.c
new file mode 100644
index 0000000..3853eab
--- /dev/null
+++ b/kernel/drivers/rtl8139.c
@@ -0,0 +1,182 @@
+#include <assert.h>
+#include <cpu/idt.h>
+#include <cpu/io.h>
+#include <drivers/pci.h>
+#include <drivers/rtl8139.h>
+#include <mmu.h>
+#include <network/arp.h>
+#include <network/ethernet.h>
+
+#define RBSTART 0x30
+#define CMD 0x37
+#define IMR 0x3C
+
+#define TSD0 0x10  // transmit status
+#define TSAD0 0x20 // transmit start address
+
+struct PCI_DEVICE rtl8139;
+uint8_t *device_buffer;
+
+uint8_t *send_buffers[4];
+
+struct _INT_PACKET_HEADER {
+  uint8_t ROK : 1;
+  uint8_t FAE : 1;
+  uint8_t CRC : 1;
+  uint8_t LONG : 1;
+  uint8_t RUNT : 1;
+  uint8_t ISE : 1;
+  uint8_t reserved : 5;
+  uint8_t BAR : 1;
+  uint8_t PAM : 1;
+  uint8_t MAR : 1;
+};
+
+struct PACKET_HEADER {
+  union {
+    uint16_t raw;
+    struct _INT_PACKET_HEADER data;
+  };
+};
+
+uint16_t current_packet_read = 0;
+
+void handle_packet(void) {
+  assert(sizeof(struct _INT_PACKET_HEADER) == sizeof(uint16_t));
+
+  uint16_t *buf = (uint16_t *)(device_buffer + current_packet_read);
+  struct PACKET_HEADER packet_header;
+  packet_header.raw = *buf;
+  assert(packet_header.data.ROK);
+  kprintf("packet_header.raw: %x\n", packet_header.raw);
+  uint16_t packet_length = *(buf + 1);
+  kprintf("packet_length: %x\n", packet_length);
+
+  uint8_t packet_buffer[8192 + 16];
+  if (current_packet_read + packet_length >= 8192 + 16) {
+    uint32_t first_run = ((uint8_t *)buf + (8192 + 16)) - device_buffer;
+    memcpy(packet_buffer, buf, first_run);
+    memcpy(packet_buffer, device_buffer, packet_length - first_run);
+  } else {
+    memcpy(packet_buffer, buf, packet_length);
+  }
+
+  handle_ethernet((uint8_t *)packet_buffer + 4, packet_length);
+
+  // Thanks to exscape
+  // https://github.com/exscape/exscapeOS/blob/master/src/kernel/net/rtl8139.c
+  // and the programmers guide
+  // https://www.cs.usfca.edu/~cruse/cs326f04/RTL8139_ProgrammersGuide.pdf I
+  // have no clue what this calculation, I can't find anything possibly relating
+  // to this in the manual, but it does work I guess.
+  current_packet_read = (current_packet_read + packet_length + 4 + 3) & (~3);
+  current_packet_read %= 8192 + 16;
+  outw(rtl8139.gen.base_mem_io + 0x38, current_packet_read - 0x10);
+}
+
+__attribute__((interrupt)) void rtl8139_handler(void *regs) {
+  (void)regs;
+  uint16_t status = inw(rtl8139.gen.base_mem_io + 0x3e);
+  kprintf("status: %x\n", status);
+
+  outw(rtl8139.gen.base_mem_io + 0x3E, 0x5);
+  if (status & (1 << 2)) {
+    kprintf("Packet sent\n");
+  }
+  if (status & (1 << 0)) {
+    kprintf("Received packet\n");
+    handle_packet();
+  }
+
+  EOI(0xB);
+}
+
+int rtl8139_send_data(uint8_t *data, uint16_t data_size) {
+  const struct PCI_DEVICE *device = &rtl8139;
+  // FIXME: It should block or fail if there is too little space for the
+  // buffer
+  if (data_size > 0x1000)
+    return 0;
+  static int loop = 0;
+  if (loop > 3) {
+    loop = 0;
+  }
+  memcpy(send_buffers[loop], data, data_size);
+  outl(device->gen.base_mem_io + 0x20 + loop * 4,
+       (uint32_t)virtual_to_physical(send_buffers[loop], NULL));
+  outl(device->gen.base_mem_io + 0x10 + loop * 4, data_size);
+  loop += 1;
+  return 1;
+}
+
+void get_mac_address(uint8_t mac[6]) {
+  uint32_t base_address = rtl8139.gen.base_mem_io;
+  // Read the MAC address
+  uint64_t mac_address;
+  {
+    uint32_t low_mac = inl(base_address);
+    uint16_t high_mac = inw(base_address + 0x4);
+    mac_address = ((uint64_t)high_mac << 32) | low_mac;
+  }
+  kprintf("mac_address: %x\n", mac_address);
+  memcpy(mac, &mac_address, sizeof(uint8_t[6]));
+}
+
+uint8_t rtl8139_get_transmit_status(uint32_t base_address) {
+  uint32_t status_register = inl(base_address + 0x3E);
+  if ((status_register >> 3) & 0x1)
+    kprintf("transmit error :(\n");
+  uint8_t status = (status_register >> 2) & 0x1;
+  outl(base_address + 0x3E, 0x5);
+  return status;
+}
+
+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 = rtl8139.gen.base_mem_io;
+  uint8_t interrupt_line = pci_get_interrupt_line(&rtl8139);
+
+  // Enable bus mastering
+  uint32_t register1 = pci_config_read32(&rtl8139, 0, 0x4);
+  register1 |= (1 << 2);
+  pci_config_write32(&rtl8139, 0, 0x4, register1);
+
+  // 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);)
+    ;
+  device_buffer = ksbrk(8192 + 16);
+  memset(device_buffer, 0, 8192 + 16);
+  // 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, (1 << 2) | (1 << 3) | (1 << 0));
+
+  // Set transmit and reciever enable
+  outb(base_address + 0x37, (1 << 2) | (1 << 3));
+
+  // Configure the recieve buffer
+  outl(base_address + 0x44,
+       0xf); // 0xf is AB+AM+APM+AAP
+
+  install_handler(rtl8139_handler, INT_32_INTERRUPT_GATE(0x0),
+                  0x20 + interrupt_line);
+
+  // ksbrk() seems to have the magical ability of disabling interrupts?
+  // I have no fucking clue why that happens and it was a pain to debug.
+  for (int i = 0; i < 4; i++)
+    send_buffers[i] = ksbrk(0x1000);
+}