void __pci_parse(struct pci_device *pdev)
{
/* first determine header type */
uint8_t header = pci_config_read_byte(pdev, 0x0E);
if (header == 0x00)
{
int need_eprom = 1;
/* determine bars and iobases */
for(int i = 0; i < 6; i++)
{
/* there are 6 BARs read them, check if the first byte is 1 */
uint32_t r = pci_config_read_dword(pdev, 0x10 + i * 4);
if (r & 1)
pdev->iobase = r & 0xFFFFFFFC;
else {
pdev->membase = r;
if (!r)
continue;
need_eprom = 0;
pci_config_write_dword(pdev, 0x10 + i * 4, 0xffffffff);
uint32_t size = pci_config_read_dword(pdev, 0x10 + i * 4);
size &= 0xfffffff0;
size = ~size;
size += 1;
pci_config_write_dword(pdev, 0x10 + i * 4, pdev->membase);
pdev->memsize = size;
if (pdev->memsize != 0)
printk("membase: 0x%x size: %d\n", pdev->membase, size);
}
}
if (need_eprom) {
uint32_t eprom = pci_config_read_dword(pdev, 0x30);
if (eprom) {
pci_config_write_dword(pdev, 0x30, 0xffffffff);
uint32_t size = pci_config_read_dword(pdev, 0x30);
size &= 0xfffffff0;
size = ~size;
size += 1;
pci_config_write_dword(pdev, 0x30, eprom);
printk("eprom is 0x%x && size is 0x%x\n", eprom, size);
}
}
/* read IRQ */
uint8_t irq = pci_config_read_byte(pdev, 0x3C);
pdev->irq = irq;
} else {
pci_info(pdev, "unknown header!\n");
}
}
// Writes an 8-bit value to a PCI device's configuration space.
void pci_config_write_byte(uint32_t bus, uint32_t device, uint32_t function, uint32_t offset, uint8_t data) {
uint32_t result = pci_config_read_dword(bus, device, function, offset);
uint32_t t_offset = (offset & 0x03) * 8;
result &= ~(0xFF << t_offset);
result |= ((uint32_t)data << t_offset);
pci_config_write_dword(bus, device, function, offset, data);
}