임베디드 시스템 엔지니어를 위한 리눅스 커널 분석
이전5장. 리눅스 커널 부팅다음

5.8. dmesg 정리

/var/log/dmesg는 부팅하는 동안 커널의 기록을 남겨 놓은 파일이다. 이 파일의 출력을 구분지어 어느 단계에서 어떤 메시지가 출력되는지 보자.

단계를 구분지어 놓으면 start_kernel()을 분석하는데 많은 도움이 될 것이고 커널 부팅 중에 에러가 났다면 어느 단계에서 에러 났는지 범위를 좁히고 찾아내는데 많은 도움이 될 것이다. 

(1)
Linux version 2.4.16 (root@halite) (gcc version 2.95.3 20010315 (release)) #22 2002. 02. 27. (수) 13:30:14 KST
(2)
BIOS-provided physical RAM map:
 BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
 BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
 BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
 BIOS-e820: 0000000000100000 - 000000001ffec000 (usable)
 BIOS-e820: 000000001ffec000 - 000000001ffef000 (ACPI data)
 BIOS-e820: 000000001ffef000 - 000000001ffff000 (reserved)
 BIOS-e820: 000000001ffff000 - 0000000020000000 (ACPI NVS)
 BIOS-e820: 00000000ffff0000 - 0000000100000000 (reserved)
(3)
On node 0 totalpages: 131052
zone(0): 4096 pages.
zone(1): 126956 pages.
zone(2): 0 pages.
(4)
Local APIC disabled by BIOS -- reenabling.
Found and enabled local APIC!
(5)
Kernel command line: BOOT_IMAGE=linux ro root=301 mem=nopentium hdd=ide-scsi
ide_setup: hdd=ide-scsi
(6)
Initializing CPU#0
(7)
Detected 1009.016 MHz processor.
(8)
Console: colour VGA+ 132x43
(9)
Calibrating delay loop... 2011.95 BogoMIPS
(10)
Memory: 512920k/524208k available (1213k kernel code, 10900k reserved, 482k data, 228k init, 0k highmem)
Checking if this processor honours the WP bit even in supervisor mode... Ok.
(11)
Dentry-cache hash table entries: 65536 (order: 7, 524288 bytes)
(12)
Inode-cache hash table entries: 32768 (order: 6, 262144 bytes)
(13)
Mount-cache hash table entries: 8192 (order: 4, 65536 bytes)
(14)
Buffer-cache hash table entries: 32768 (order: 5, 131072 bytes)
(15)
Page-cache hash table entries: 131072 (order: 7, 524288 bytes)
(16)
CPU: Before vendor init, caps: 0183fbff c1c7fbff 00000000, vendor = 2
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#0.
CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
CPU: L2 Cache: 256K (64 bytes/line)
CPU: After vendor init, caps: 0183fbff c1c7fbff 00000000 00000000
CPU:     After generic, caps: 0183fbff c1c7fbff 00000000 00000000
CPU:             Common caps: 0183fbff c1c7fbff 00000000 00000000
CPU: AMD Athlon(tm) Processor stepping 02
Enabling fast FPU save and restore... done.
Checking 'hlt' instruction... OK.
(17)
POSIX conformance testing by UNIFIX
(18)
enabled ExtINT on CPU#0
ESR value before enabling vector: 00000000
ESR value after enabling vector: 00000000
(19)
Using local APIC timer interrupts.
(20)
calibrating APIC timer ...
..... CPU clock speed is 1009.0421 MHz.
..... host bus clock speed is 201.8084 MHz.
(21)
cpu: 0, clocks: 2018084, slice: 1009042
CPU0<T0:2018080,T1:1009024,D:14,S:1009042,C:2018084>
(22)
mtrr: v1.40 (20010327) Richard Gooch (rgooch@atnf.csiro.au)
mtrr: detected mtrr type: Intel
(23)
PCI: PCI BIOS revision 2.10 entry at 0xf1180, last bus=1
(24)
PCI: Using configuration type 1
(25)
PCI: Probing PCI hardware
(26)
Unknown bridge resource 0: assuming transparent
(27)
PCI: Using IRQ router VIA [1106/0686] at 00:04.0
PCI: Found IRQ 10 for device 00:0b.0
PCI: Sharing IRQ 10 with 00:11.0
PCI: Found IRQ 5 for device 00:0d.0
PCI: Sharing IRQ 5 with 00:04.2
PCI: Sharing IRQ 5 with 00:04.3
PCI: Disabling Via external APIC routing
(28)
isapnp: Scanning for PnP cards...
isapnp: No Plug & Play device found
(29)
Linux NET4.0 for Linux 2.4
Based upon Swansea University Computer Society NET3.039
(30)
Initializing RT netlink socket
(31)
apm: BIOS version 1.2 Flags 0x03 (Driver version 1.15)
(32)
Starting kswapd
JFS development version: $Name:  $
(33)
ACPI: APM is already active, exiting
(34)
pty: 256 Unix98 ptys configured
(35)
Serial driver version 5.05c (2001-07-08) with MANY_PORTS SHARE_IRQ SERIAL_PCI ISAPNP enabled
ttyS01 at 0x02f8 (irq = 3) is a 16550A
(36)
block: 128 slots per queue, batch=32
(37)
Uniform Multi-Platform E-IDE driver Revision: 6.31
(38)
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
(39)
VP_IDE: IDE controller on PCI bus 00 dev 21
VP_IDE: chipset revision 16
VP_IDE: not 100% native mode: will probe irqs later
VP_IDE: VIA vt82c686a (rev 22) IDE UDMA66 controller on pci00:04.1
    ide0: BM-DMA at 0xd800-0xd807, BIOS settings: hda:DMA, hdb:DMA
    ide1: BM-DMA at 0xd808-0xd80f, BIOS settings: hdc:DMA, hdd:DMA
(40)
PDC20265: IDE controller on PCI bus 00 dev 88
PCI: Found IRQ 10 for device 00:11.0
PCI: Sharing IRQ 10 with 00:0b.0
PDC20265: chipset revision 2
PDC20265: not 100% native mode: will probe irqs later
    ide2: BM-DMA at 0x8000-0x8007, BIOS settings: hde:DMA, hdf:DMA
    ide3: BM-DMA at 0x8008-0x800f, BIOS settings: hdg:DMA, hdh:pio
(41)
hda: Maxtor 4W080H6, ATA DISK drive
hdb: IC35L040AVER07-0, ATA DISK drive
hdc: QUANTUM FIREBALLlct15 20, ATA DISK drive
hdd: LG CD-RW CED-8080B, ATAPI CD/DVD-ROM drive
(42)
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
hda: 160086528 sectors (81964 MB) w/2048KiB Cache, CHS=9964/255/63, UDMA(33)
hdb: 80418240 sectors (41174 MB) w/1916KiB Cache, CHS=5005/255/63, UDMA(33)
hdc: 39876480 sectors (20417 MB) w/418KiB Cache, CHS=39560/16/63, UDMA(33)
(43)
Partition check:
 hda: hda1 hda2
 hdb: hdb1
 hdc: [PTBL] [2482/255/63] hdc1 hdc2 hdc3
(44)
Floppy drive(s): fd0 is 1.44M
FDC 0 is a post-1991 82077
(45)
Linux agpgart interface v0.99 (c) Jeff Hartmann
agpgart: Maximum main memory to use for agp memory: 439M
agpgart: Detected Via Apollo Pro KT133 chipset
agpgart: AGP aperture is 128M @ 0xe0000000
[drm] AGP 0.99 on VIA Apollo KT133 @ 0xe0000000 128MB
[drm] Initialized mga 3.0.2 20010321 on minor 0
(46)
Linux Kernel Card Services 3.1.22
  options:  [pci] [cardbus] [pm]
(47)
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP, IGMP
IP: routing cache hash table of 4096 buckets, 32Kbytes
TCP: Hash tables configured (established 32768 bind 32768)
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
(48)
ds: no socket drivers loaded!
(49)
request_module[nls_EUC-KR]: Root fs not mounted
Unable to load NLS charset EUC-KR
(50)
VFS: Mounted root (jfs filesystem) readonly.
(51)
Freeing unused kernel memory: 228k freed

(1)
start_kernel()
(2)
setup_memory_region()/setup_arch()/start_kerenel()
(3)
free_area_init_core()/free_area_init()/paging_init()/setup_arch()/start_kernel()
(4)
detect_init_APIC()/init_apic_mappings()/setup_arch()/start_kernel()
(5)
start_kernel()
(6)
cpu_init()/trap_init()/start_kernel()
(7)
time_init()/start_kernel()
(8)
con_init()/console_init()/start_kernel()
(9)
calibrate_delay()/start_kernel()
(10)
mem_init()/start_kernel()
(11)
dcache_init()/vfs_caches_init()/start_kernel()
(12)
inode_init()/vfs_caches_init()/start_kernel()
(13)
mnt_init()/vfs_caches_init()/start_kernel()
(14)
buffer_init()/start_kernel()
(15)
page_cache_init()/start_kernel()
(16)
identify_cpu()/check_bugs()/start_kernel()
(17)
start_kernel()
(18)
setup_local_APIC()/APIC_init_uniprocessor()/smp_init()/start_kernel()
(19)
setup_APIC_clocks()/APIC_init_uniprocessor/smp_init()/start_kernel()
(20)
calibrate_APIC_clock()/setup_APIC_clocks()/APIC_init_uniprocessor/smp_init()/ start_kernel()
(21)
setup_APIC_timer()/setup_APIC_clocks()/APIC_init_uniprocessor/smp_init()/start_kernel()
(22)
mtrr_setup()/mtrr_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(23)
check_pcibios()/pci_find_bios()/pcibios_config_init()/pcibios_init()/pci_init()/ do_basic_setup()/init()/rest_init()/start_kernel()
(24)
pci_check_direct()/pcibios_config_init()/pcibios_init()/pci_init()/ do_basic_setup()/init()/rest_init()/start_kernel()
(25)
pcibios_init()/pci_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(26)
pci_read_bridge_bases()/pcibios_fixup_bus()/pci_do_scan_bus()/pci_scan_bus()/ pcibios_init()/pci_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(27)
pirq_find_router()/pcibios_irq_init()/ pcibios_init()/pci_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(28)
isapnp_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(29)
sock_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(30)
rtnetlink_init()/sock_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(32)
kswapd_init()/do_initcalls()/do_basic_setup()/init()/rest_init()/start_kernel()
(33)
acpi_init()/do_initcalls()/do_basic_setup()/init()/rest_init()/start_kernel()
(34)
pty_init()/do_initcalls()/do_basic_setup()/init()/rest_init()/start_kernel()
(35)
show_serial_version()/rs_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(36)
blk_dev_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(37)
ide_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(38)
ide_system_bus_speed()/ide_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(39)
ide_scan_pcidev()/ide_scan_pcibus()/probe_for_hwifs()/ide_init_builtin_drivers()/ ide_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(40)
ide_setup_pci_device()/ide_scan_pcidev()/ide_scan_pcibus()/probe_for_hwifs()/ ide_init_builtin_drivers()/ide_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(41)
do_identify()/actual_try_to_identify()/try_to_identify()/do_probe()/probe_for_drive()/ probe_hwif()/ideprobe_init()/init_module()/do_basic_setup()/init()/rest_init()/start_kernel()
(42)
init_irq()/hwif_init()/ideprobe_init()/init_module()/do_basic_setup()/init()/rest_init()/ start_kernel()
(43)
check_partition()/grok_partitions()/idedisk_revalidate/init_module()/do_basic_setup()/ init()/rest_init()/start_kernel()
(44)
config_types()/floppy_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(45)
agp_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(46)
init_pcmcia_cs()/do_basic_setup()/init()/rest_init()/start_kernel()
(47)
inet_init()/do_basic_setup()/init()/rest_init()/start_kernel()
(48)
init_pcmcia_ds()/do_basic_setup()/init()/rest_init()/start_kernel()
(49)
request_module()/load_nls()/init_nls_euc_kr()/do_basic_setup()/init()/ rest_init()/start_kernel()
(50)
mount_root()/prepare_namespace()/init()/rest_init()/start_kernel()
(51)
free_initmem()/init()/rest_init()/start_kernel()

커널의 초기화 동안 등록된 드라이버들이 자동으로 실행되고 초기화 되도록 하는데, 커널을 어떻게 설정하는가에 따라 커널에 포함되는 것이 다르므로 일일히 기록하는 대신에 자동으로 커널 컴파일하는 동안 포함되도록 할 수 있다. 필요한 모듈에 __init란 속성을 사용하고 module_init()를 사용해 이런 일이 가능하도록 한다.

module_init()는 include/linux/init.h에 다음과 같이 정의되어 있다. 

#define module_init(x)  __initcall(x);

__initcall(x)는 module로 지정됐는가 아닌가에 따라 정의가 달라지는데 어찌됐든 .initcall.init란 섹션에 속하게 된다. 여기에 속하면 커널의 링킹 동안 모아진 .initcall.init가 do_basic_setup() 혹은 do_initcalls()에 의해 자동으로 불려지게 된다(vmlinux.lds를 보면 .initcall.init를 모아주는 부분이 있다).

이전처음으로다음
init()위로디바이스 드라이버