Question

我有一个带有二进制 Linux 2.6.18 内核的旧设备，该内核正常启动到其rootfs。但是，如果我尝试从源代码编译此内核，则生成的内核二进制文件将在引导期间冻结。我没有.config文件用于构建当前正常启动的先前内核二进制文件。

启动冻结，未提供错误输出。这是启动日志：

Linux version 2.6.18-6.2 (myuser@host) (gcc version 4.2.0 20070124 (prerelease) - BRCM 10ts-20080721) #10 SMP Sun Apr 28 18:25:24 BRT 2013
Fetching vars from bootloader... OK (E,d,B,C)
Detected 512 MB on MEMC0 (strap 0x23430310)
Board strapped at 512 MB, default is 256 MB
Options: sata=1 enet=1 emac_1=1 no_mdio=0 docsis=0 ebi_war=0 pci=1 smp=1
CPU revision is: 0002a044
FPU revision is: 00130001
Primary instruction cache 32kB, physically tagged, 2-way, linesize 64 bytes.
Primary data cache 64kB, 4-way, linesize 64 bytes.
<6>Synthesized TLB refill handler (23 instructions).
<6>Synthesized TLB load handler fastpath (37 instructions).
<6>Synthesized TLB store handler fastpath (37 instructions).
<6>Synthesized TLB modify handler fastpath (36 instructions).
Determined physical RAM map:
 memory: 10000000 @ 00000000 (usable)
 memory: 10000000 @ 20000000 (usable)
Using 32MB for memory, overwrite by passing mem=xx
User-defined physical RAM map:
node [00000000, 02000000: RAM]
node [02000000, 0e000000: RSVD]
node [20000000, 10000000: RAM]
<5>Reserving 224 MB upper memory starting at 02000000
<7>On node 0 totalpages: 65536
<7>  DMA zone: 65536 pages, LIFO batch:15
<7>On node 1 totalpages: 65536
<7>  Normal zone: 65536 pages, LIFO batch:15
Built 2 zonelists.  Total pages: 131072
<5>Kernel command line: root=/dev/mtdblock3 rw rootfstype=jffs2 console=ttyS0,115200
PID hash table entries: 4096 (order: 12, 16384 bytes)
mips_counter_frequency = 202000000 from Calibration, = 202500000 from header(CPU_MHz/2)
Dentry cache hash table entries: 65536 (order: 6, 262144 bytes)
Inode-cache hash table entries: 32768 (order: 5, 131072 bytes)
Memory: 286336k/524288k available (2924k kernel code, 237760k reserved, 544k data, 164k init, 0k highmem)
Mount-cache hash table entries: 512
Checking for 'wait' instruction...  available.
plat_prepare_cpus: ENABLING 2nd Thread...
TP0: prom_boot_secondary: Kick off 2nd CPU...
CPU revision is: 0002a044
FPU revision is: 00130001
Primary instruction cache 32kB, physically tagged, 2-way, linesize 64 bytes.
Primary data cache 64kB, 4-way, linesize 64 bytes.
Synthesized TLB refill handler (23 instructions).
Brought up 2 CPUs
migration_cost=1000
NET: Registered protocol family 16
registering PCI controller with io_map_base unset
registering PCI controller with io_map_base unset
SCSI subsystem initialized
usbcore: registered new driver usbfs
usbcore: registered new driver hub
NET: Registered protocol family 2
IP route cache hash table entries: 16384 (order: 4, 65536 bytes)
TCP established hash table entries: 65536 (order: 7, 524288 bytes)
TCP bind hash table entries: 32768 (order: 6, 262144 bytes)
TCP: Hash tables configured (established 65536 bind 32768)
TCP reno registered
brcm-pm: disabling power to USB block
brcm-pm: disabling power to ENET block
brcm-pm: disabling power to SATA block
squashfs: version 3.2-r2 (2007/01/15) Phillip Lougher
JFFS2 version 2.2. (NAND) (SUMMARY)  (C) 2001-2006 Red Hat, Inc.
io scheduler noop registered
io scheduler anticipatory registered (default)
io scheduler deadline registered
io scheduler cfq registered
Serial: 8250/16550 driver $Revision: 1.1.1.1 $ 3 ports, IRQ sharing disabled
serial8250: ttyS0 at MMIO 0x0 (irq = 22) is a 16550A
serial8250: ttyS1 at MMIO 0x0 (irq = 66) is a 16550A
serial8250: ttyS2 at MMIO 0x0 (irq = 67) is a 16550A
loop: loaded (max 8 devices)
brcm-pm: enabling power to ENET block

我该如何调试？我们也欢迎任何关于冻结可能解决方案的见解。

Answer 1

解决此问题的一种方法是启用CONFIG_EARLY_PRINTK并在内核代码中添加一些您怀疑正在冻结的printk()语句（很可能是某些驱动程序配置参数错误）。

此外，您可以通过查看/boot/config-*或/proc/config.gz来获取旧的内核配置（仅当旧内核启用了选项CONFIG_IKCONFIG_PROC时才会存在）。

Answer 2

有一些调试器选项，比如kdb和kgdb，但我总是发现它们片状和气质。可能更多 - 如果你甚至无法让你的机器启动。我同意CONFIG_EARLY_PRINTK的建议，并建议你确保在启动时获得内核输出（而不是＆＃34;安静＆＃34;），但似乎你已经有了这个。

＆＃34; GPIO＆＃34;上面的建议可行 - 但是系统依赖且繁琐。也就是说，我认为你想要一个比＃34更好的答案;开始添加很多printk＆＃34;。你可以从有问题的以太网驱动程序（BRC-PM？）开始，或者尝试删除以查看它是否相关。

它会进行一些调查 - 抱歉，但没有＆＃34;魔法子弹＆＃34;！：-O

Answer 3

将initcall_debug添加到CONFIG_CMDLINE（内核命令行）。

CONFIG_CMDLINE="root=/dev/ram0 rw mem=512M@0x0 initrd=0x800000,16M console=ttyS0,38400n8 rootfstype=ext2 init=/bin/busybox init -s initcall_debug"

如何调试在引导期间冻结的Linux内核？

3 个答案: