這篇文章只是拿來記錄compile Kernel for Cortex-A57, 用於研究PCIe Driver, 其餘的rootfs與busybox請參考附錄
[brook@:~/Projects/qemu/linux-virt]$ sudo apt-get install gcc-aarch64-linux-gnu #for ARM64 [brook@:~/Projects/qemu/linux-virt]$ export ARCH=arm64 [brook@:~/Projects/qemu/linux-virt]$ export CROSS_COMPILE=aarch64-linux-gnu- [brook@:~/Projects/qemu/linux-virt]$ cp arch/arm64/configs/defconfig .config [brook@:~/Projects/qemu/linux-virt]$ make olddefconfig HOSTCC scripts/basic/fixdep HOSTCC scripts/kconfig/conf.o HOSTCC scripts/kconfig/confdata.o HOSTCC scripts/kconfig/expr.o LEX scripts/kconfig/lexer.lex.c YACC scripts/kconfig/parser.tab.[ch] HOSTCC scripts/kconfig/lexer.lex.o HOSTCC scripts/kconfig/parser.tab.o HOSTCC scripts/kconfig/preprocess.o HOSTCC scripts/kconfig/symbol.o HOSTLD scripts/kconfig/conf scripts/kconfig/conf --olddefconfig Kconfig # # configuration written to .config # [brook@:~/Projects/qemu/linux-virt]$ make -j16 [brook@:~/Projects/qemu/linux-virt]$ qemu-system-aarch64 -machine virt -cpu cortex-a57 -smp 8 -m 4096 -kernel ./arch/arm64/boot/Image -append "console=ttyAMA0 root=/dev/vda" -nographic -initrd ../initrd-arm.img [ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x411fd070] ... Please press Enter to activate this console. / # / # lspci -k 00:01.0 Class 0200: 1af4:1000 virtio-pci 00:00.0 Class 0600: 1b36:0008 / # uname -r 5.4.01af4:1000是Virtio network device, 而1b36:0008是QEMU PCIe Host bridge
ETH PCIe driver在"drivers/virtio/virtio_pci_common.c", 其vendor ID是0x1af4, 當device插入時, 就會去比對ID, match後就會載入該module並probe
/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
static const struct pci_device_id virtio_pci_id_table[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) },
{ 0 }
};
MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
...
static struct pci_driver virtio_pci_driver = {
.name = "virtio-pci",
.id_table = virtio_pci_id_table,
.probe = virtio_pci_probe,
.remove = virtio_pci_remove,
#ifdef CONFIG_PM_SLEEP
.driver.pm = &virtio_pci_pm_ops,
#endif
.sriov_configure = virtio_pci_sriov_configure,
};
module_pci_driver(virtio_pci_driver);
這裡我把PCI ID移成PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET + 1, 再透過echo <vendor_code> <device_code> > /sys/bus/pci/drivers/<pci_device_driver>/new_id動態對PCIe driver新增ID, 讓系統認到網卡
[brook@:~/Projects/qemu/linux-virt]$ git diff .
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index f2862f66c2ac..60aef3fea650 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -492,7 +492,7 @@ static const struct dev_pm_ops virtio_pci_pm_ops = {
/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
static const struct pci_device_id virtio_pci_id_table[] = {
- { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) },
+ { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET + 1, PCI_ANY_ID) },
{ 0 }
};
@@ -514,6 +514,7 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
{
struct virtio_pci_device *vp_dev, *reg_dev = NULL;
int rc;
+ printk("%s(#%d): Brook\n", __FUNCTION__, __LINE__);
/* allocate our structure and fill it out */
vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
lspci會認到1af4:1000, 但是eth driver因為被我跳號, 所以認不到, 再透過/sys/bus/pci/drivers/<pci_device_driver>/new_id將往卡帶起來
/ # lspci
00:01.0 Class 0200: 1af4:1000
00:00.0 Class 0600: 1b36:0008
/ # ifconfig -a
lo Link encap:Local Loopback
LOOPBACK MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
/ # echo 1af4 1000 > /sys/bus/pci/drivers/virtio-pci/new_id
[ 130.728345] virtio_pci_probe(#517): Brook
[ 130.729216] virtio-pci 0000:00:01.0: enabling device (0000 -> 0003)
/ # ifconfig -a
eth0 Link encap:Ethernet HWaddr 52:54:00:12:34:56
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
lo Link encap:Local Loopback
LOOPBACK MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
透過echo <Domain:Bus:Device.Function> > /sys/bus/pci/drivers/<pci_device_driver>/unbind將driver移除, 也可以透過echo <Domain:Bus:Device.Function> > /sys/bus/pci/drivers/<pci_device_driver>/bind重新將driver帶上
/ # lspci
00:01.0 Class 0200: 1af4:1000
00:00.0 Class 0600: 1b36:0008
/ # echo 0000:00:01.0 > /sys/bus/pci/drivers/virtio-pci/unbind
[ 5163.097254] hrtimer: interrupt took 87350512 ns
/ # ifconfig -a
lo Link encap:Local Loopback
LOOPBACK MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
/ # echo 0000:00:01.0 > /sys/bus/pci/drivers/virtio-pci/bind
[ 5183.251580] virtio_pci_probe(#517): Brook
/ # ifconfig -a
eth0 Link encap:Ethernet HWaddr 52:54:00:12:34:56
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
lo Link encap:Local Loopback
LOOPBACK MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
-
參考資料:
- https://blog.csdn.net/zhqh100/article/details/51173275, qemu模拟Cortex-A57运行Linux4.5.1
- Build the Linux Kernel and Busybox for ARM and run them on QEMU
- https://zhuanlan.zhihu.com/p/113467453, qemu PCIe总线结构
- https://pci-ids.ucw.cz/read/PC/1af4, The PCI ID Repository
- https://stackoverflow.com/questions/22901282/hard-time-in-understanding-module-device-tableusb-id-table-usage, Hard time in understanding MODULE_DEVICE_TABLE(usb, id_table) usage
LDD3 - Chapter 12. PCI Drivers
回覆刪除MODULE_DEVICE_TABLE
This pci_device_id structure needs to be exported to user space to allow the hotplug and module loading systems know what module works with what hardware devices. The macro MODULE_DEVICE_TABLE accomplishes this. An example is:
MODULE_DEVICE_TABLE(pci, i810_ids);
This statement creates a local variable called _ _mod_pci_device_table that points to the list of struct pci_device_id. Later in the kernel build process, the depmod program searches all modules for the symbol _ _mod_pci_device_table. If that symbol is found, it pulls the data out of the module and adds it to the file /lib/modules/KERNEL_VERSION/modules.pcimap. After depmod completes, all PCI devices that are supported by modules in the kernel are listed, along with their module names, in that file. When the kernel tells the hotplug system that a new PCI device has been found, the hotplug system uses the modules.pcimap file to find the proper driver to load.