升级linux内核后挂起/sbin/init

Question

我正在使用ARM SOC (AT91SAM9G25)将内核从3.2升级到4.4。这是一个系统系统。前面的3.2运行良好，但是在引导4.4内核时，它挂在/sbin/init的执行部分之后。我可以在prompt引导程序上指定'init=/bin/sh‘，它成功地执行shell (我得到一个shell提示符)。从这里看，事情是正确的；我可以挂载/proc，验证rootfs是否已经挂载，打开一个NIC接口等等。

我在运行不同ARM SOC (AT91SAM9G45)的不同平台上成功地完成了这一升级。我比较了这个正在工作的其他平台和挂起的平台之间的内核信任。唯一的区别是那些与不同的国有企业有关的。内核配置差异如下：

300,301c300,301
< CONFIG_PLATFORM_SLK1=y
< # CONFIG_PLATFORM_SLK2 is not set
---
> # CONFIG_PLATFORM_SLK1 is not set
> CONFIG_PLATFORM_SLK2=y
421c421
< CONFIG_ARM_APPENDED_DTB_FILE="arch/arm/boot/dts/slk1.dtb"
---
> CONFIG_ARM_APPENDED_DTB_FILE="arch/arm/boot/dts/slk2.dtb"
1061c1061
< # CONFIG_MTD_M25P80 is not set
---
> CONFIG_MTD_M25P80=y
1311,1314c1311
< CONFIG_NET_VENDOR_MICREL=y
< # CONFIG_KS8842 is not set
< # CONFIG_KS8851 is not set
< # CONFIG_KS8851_MLL is not set
---
> # CONFIG_NET_VENDOR_MICREL is not set
2414c2411,2450
< # CONFIG_USB_GADGET is not set
---
> CONFIG_USB_GADGET=y
> # CONFIG_USB_GADGET_DEBUG is not set
> # CONFIG_USB_GADGET_DEBUG_FILES is not set
> # CONFIG_USB_GADGET_DEBUG_FS is not set
> CONFIG_USB_GADGET_VBUS_DRAW=2
> CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS=2
> 
> #
> # USB Peripheral Controller
> #
> # CONFIG_USB_AT91 is not set
> CONFIG_USB_ATMEL_USBA=y
> # CONFIG_USB_FUSB300 is not set
> # CONFIG_USB_FOTG210_UDC is not set
> # CONFIG_USB_GR_UDC is not set
> # CONFIG_USB_R8A66597 is not set
> # CONFIG_USB_PXA27X is not set
> # CONFIG_USB_MV_UDC is not set
> # CONFIG_USB_MV_U3D is not set
> # CONFIG_USB_M66592 is not set
> # CONFIG_USB_BDC_UDC is not set
> # CONFIG_USB_NET2272 is not set
> # CONFIG_USB_GADGET_XILINX is not set
> # CONFIG_USB_DUMMY_HCD is not set
> # CONFIG_USB_CONFIGFS is not set
> # CONFIG_USB_ZERO is not set
> # CONFIG_USB_AUDIO is not set
> # CONFIG_USB_ETH is not set
> # CONFIG_USB_G_NCM is not set
> # CONFIG_USB_GADGETFS is not set
> # CONFIG_USB_FUNCTIONFS is not set
> # CONFIG_USB_MASS_STORAGE is not set
> # CONFIG_USB_G_SERIAL is not set
> # CONFIG_USB_MIDI_GADGET is not set
> # CONFIG_USB_G_PRINTER is not set
> # CONFIG_USB_CDC_COMPOSITE is not set
> # CONFIG_USB_G_ACM_MS is not set
> # CONFIG_USB_G_MULTI is not set
> # CONFIG_USB_G_HID is not set
> # CONFIG_USB_G_DBGP is not set
2584,2585c2620,2621
< # CONFIG_RTC_DRV_AT91RM9200 is not set
< CONFIG_RTC_DRV_AT91SAM9=y
---
> CONFIG_RTC_DRV_AT91RM9200=y
> # CONFIG_RTC_DRV_AT91SAM9 is not set
2599c2635
< # CONFIG_AT_HDMAC is not set
---
> CONFIG_AT_HDMAC=y
3058c3094
< CONFIG_DEBUG_UART_PHYS=0xffffee00
---
> CONFIG_DEBUG_UART_PHYS=0xfffff200

如果我引导到一个shell (使用init=/bin/sh)，我可以运行'/sbin/init -i‘，并且系统通常会启动(init的PID值不是1)。但是，“exec /sbin/init”或“exec/sbin/init-i”挂起。

对如何找出它挂在哪里有什么想法吗？

Answer 1

我想我已经找到这个内核挂的原因了。当init关闭控制台设备(/dev/ atmel_serial )时，UART驱动程序将禁用UART发射器。然后，内核中的下一个printk挂起，忙着等待THR为空。此错误已在上游4.4-at 91分支(https://github.com/linux4sam/linux-at91/commit/0a1757cfa5ba3b46f6ee7a74ddb7a5c0bd5d7c2f)中修复。