Boot
引導載入程序無法載入 linux 核心
我將 linux 核心從 2.6.32 升級到 3.0.7，但現在引導載入程序無法載入核心映像。具體來說，引導過程在以下情況下凍結：
Starting kernel ... Uncompressing Linux... done, booting the kernel.原因是引導載入程序*（U-Boot）*沒有正確配置，核心 2.6.x 和核心 3.0.x 之間的串列埠已從 ttySx 重命名為 ttyOx，這一事實證實了這一點。
下一步是編輯儲存在引導分區上的uEnv.txt，以便在引導過程中讀取。
uEnv.txt：
mpurate=1000 dvimode="hd720 omapfb.vram=0:8M,1:4M,2:4M" vram=16M optargs="consoleblank=0" console="tty0 console=ttyO2,115200n8"引導過程失敗並顯示：
Texas Instruments X-Loader 1.5.0 (Jun 14 2011 - 22:04:07) Beagle xM Reading boot sector Loading u-boot.bin from mmc U-Boot 2011.03-rc1-00000-g9a3cc57-dirty (Apr 01 2011 - 17:41:42) OMAP36XX/37XX-GP ES2.1, CPU-OPP2, L3-165MHz, Max CPU Clock 1 Ghz OMAP3 Beagle board + LPDDR/NAND I2C: ready DRAM: 512 MiB NAND: 0 MiB MMC: OMAP SD/MMC: 0 *** Warning - readenv() failed, using default environment In: serial Out: serial Err: serial Beagle xM Rev C No EEPROM on expansion board Die ID #7ba200029ff800000168300f0802900e Hit any key to stop autoboot: 0 The user button is currently NOT pressed. SD/MMC found on device 0 reading uEnv.txt 135 bytes read Loaded environment from uEnv.txt Importing environment from mmc ... Loading file "/boot/uImage" from mmc device 0:2 (xxa2) 2495320 bytes read Booting fromage at 80200000 ... Image Name: Linux-3.0.7 Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 2495256 Bytes = 2.4 MiB Load Address: 80008000 Entry Point: 80008000 Verifying Checksum ... OK Loading Kernel Image ... OK OK Starting kernel ... Uncompressing Linux... done, booting the kernel. Linux version 3.0.7 (root@beagleboard) (gcc version 4.3.3 (GCC) ) #1 PREEMPT Sa4 CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=10c53c7f CPU: VIPT nonaliasing data cache, VIPT aliasing instruction cache Machine: OMAP3 Beagle Board Reserving 16777216 bytes SDRAM for VRAM Memory policy: ECC disabled, Data cache writeback OMAP3630 ES1.2 (l2cache iva sgx neon isp 192mhz_clk ) SRAM: Mapped pa 0x40200000 to va 0xfe400000 size: 0x10000 Clocking rate (Crystal/Core/MPU): 26.0/332/600 MHz Reprogramming SDRC clock to 332000000 Hz Built 1 zonelists in Zone order, mobility grouping on. Total pages: 125952 omapdss.def_disp=dvi root=/dev/mmcblk0p2 rw rootfstype=ext3 rootwait PID hash table entries: 2048 (order: 1, 8192 bytes) Dentry cache hash table entries: 65536 (order: 6, 262144 bytes) Inode-cache hash table entries: 32768 (order: 5, 131072 bytes) Memory: 496MB = 496MB total Memory: 498048k/498048k available, 26240k reserved, 0K highmem Virtual kernel memory layout: vector : 0xffff0000 - 0xffff1000 ( 4 kB) fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB) DMA : 0xffc00000 - 0xffe00000 ( 2 MB) vmalloc : 0xe0800000 - 0xf8000000 ( 376 MB) lowmem : 0xc0000000 - 0xe0000000 ( 512 MB) modules : 0xbf000000 - 0xc0000000 ( 16 MB) .init : 0xc0008000 - 0xc0029000 ( 132 kB) .text : 0xc0029000 - 0xc04b46c8 (4654 kB) .data : 0xc04b6000 - 0xc04efec0 ( 232 kB) .bss : 0xc04efee4 - 0xc05311a4 ( 261 kB) Preemptible hierarchical RCU implementation. NR_IRQS:410 IRQ: Found an INTC at 0xfa200000 (revision 4.0) with 96 interrupts Total of 96 interrupts on 1 active controller omap_hwmod: gpt12_fck: missing clockdomain for gpt12_fck. OMAP clockevent source: GPTIMER12 at 32768 Hz sched_clock: 32 bits at 32kHz, resolution 30517ns, wraps every 131071999ms Console: colour dummy device 80x30 console [tty0] enabled Calibrating delay loop... 331.40 BogoMIPS (lpj=1296384) pid_max: default: 32768 minimum: 301 Mount-cache hash table entries: 512 CPU: Testing write buffer coherency: ok devtmpfs: initialized omap_hwmod: _populate_mpu_rt_base found no _mpu_rt_va for l4_core omap_hwmod: _populate_mpu_rt_base found no _mpu_rt_va for l4_per omap_hwmod: _populate_mpu_rt_base found no _mpu_rt_va for l4_wkup omap_hwmod: i2c1: softreset failed (waited 10000 usec) omap_hwmod: i2c2: softreset failed (waited 10000 usec) omap_hwmod: i2c3: softreset failed (waited 10000 usec) print_constraints: dummy: GPMC revision 5.0 omap_device: omap_gpio.0: new worst case activate latency 0: 30517 OMAP GPIO hardware version 2.5 OMAP GPIO hardware version 2.5 OMAP GPIO hardware version 2.5 OMAP GPIO hardware version 2.5 OMAP GPIO hardware version 2.5 OMAP GPIO hardware version 2.5 omap_mux_init: Add partition: #1: core, flags: 0 OMAP3 Beagle Rev: unknown 2 Unable to get DVI reset GPIO hw-breakpoint: debug architecture 0x4 unsupported. ------------[ cut here ]------------ WARNING: at arch/arm/mach-omap2/clock.c:455 omap2_clk_switch_mpurate_at_boot+0x) clock: dpll1_ck: unable to set MPU rate to 1000: -22 [<c0032ee0>] (unwind_backtrace+0x0/0xec) from [<c00519d8>] (warn_slowpath_commo) [<c00519d8>] (warn_slowpath_common+0x48/0x60) from [<c0051a84>] (warn_slowpath_) [<c0051a84>] (warn_slowpath_fmt+0x30/0x40) from [<c000f8f4>] (omap2_clk_switch_) [<c000f8f4>] (omap2_clk_switch_mpurate_at_boot+0x80/0xb4) from [<c000f934>] (om) [<c000f934>] (omap3xxx_clk_arch_init+0xc/0x3c) from [<c0008370>] (do_one_initca) [<c0008370>] (do_one_initcall+0x94/0x15c) from [<c00084e0>] (kernel_init+0x74/0) [<c00084e0>] (kernel_init+0x74/0x11c) from [<c002f35c>] (kernel_thread_exit+0x0) ---[ end trace 1b75b31a2719ed1c ]--- OMAP DMA hardware revision 5.0 bio: create slab <bio-0> at 0 SCSI subsystem initialized omap_device: omap_i2c.1: new worst case activate latency 0: 30517 omap_i2c omap_i2c.1: bus 1 rev4.0 at 2600 kHz twl4030: PIH (irq 7) chaining IRQs 368..375 twl4030: power (irq 373) chaining IRQs 376..383 twl4030: gpio (irq 368) chaining IRQs 384..401 print_constraints: VMMC1: 1850 <--> 3150 mV at 3000 mV normal standby print_constraints: VDAC: 1800 mV normal standby print_constraints: VDVI: 1800 mV normal standby print_constraints: VSIM: 1800 <--> 3000 mV at 1800 mV normal standby omap_i2c omap_i2c.3: bus 3 rev4.0 at 100 kHz Switching to clocksource 32k_counter NTFS driver 2.1.30 [Flags: R/W]. Btrfs loaded GFS2 installed Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254) io scheduler noop registered io scheduler deadline registered io scheduler cfq registered (default) OMAP DSS rev 2.0 Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled omap_uart.0: ttyO0 at MMIO 0x4806a000 (irq = 72) is a OMAP UART0 omap_uart.1: ttyO1 at MMIO 0x4806c000 (irq = 73) is a OMAP UART1 omap_uart.2: ttyO2 at MMIO 0x49020000 (irq = 74) is a OMAP UART2 console [ttyO2] enabled omap_uart.3: ttyO3 at MMIO 0x49042000 (irq = 80) is a OMAP UART3 SCSI Media Changer driver v0.25 mousedev: PS/2 mouse device common for all mice input: gpio-keys as /devices/platform/gpio-keys/input/input0 input: twl4030_pwrbutton as /devices/platform/omap/omap_i2c.1/i2c-1/1-0049/twl41 i2c /dev entries driver lirc_dev: IR Remote Control driver registered, major 252 IR NEC protocol handler initialized IR RC5(x) protocol handler initialized IR RC6 protocol handler initialized IR JVC protocol handler initialized IR Sony protocol handler initialized IR RC5 (streamzap) protocol handler initialized IR LIRC bridge handler initialized Linux video capture interface: v2.00 i2c-core: driver [msp3400] using legacy suspend method i2c-core: driver [msp3400] using legacy resume method vivi-000: V4L2 device registered as video0 Video Technology Magazine Virtual Video Capture Board ver 0.8.0 successfully lo. vpfe_init VFP support v0.3: implementor 41 architecture 3 part 30 variant c rev 3 ThumbEE CPU extension supported. omap_voltage_late_init: Unable to create voltage debugfs main dir vdd_debugfs_init: Unable to create debugfs directory for vdd_mpu vdd_debugfs_init: Unable to create debugfs directory for vdd_core sr_init: No PMIC hook to init smartreflex smartreflex smartreflex.0: omap_sr_probe: SmartReflex driver initialized smartreflex: probe of smartreflex.0 failed with error -22 smartreflex smartreflex.1: omap_sr_probe: SmartReflex driver initialized smartreflex: probe of smartreflex.1 failed with error -22 sr_init: platform driver register failed for SR clock: disabling unused clocks to save power omapfb omapfb: no driver for display omapfb omapfb: failed to setup omapfb regulator_init_complete: VDVI: incomplete constraints, leaving on regulator_init_complete: VDAC: incomplete constraints, leaving on regulator_init_complete: VMMC1: incomplete constraints, leaving on omap_vout omap_vout: probed for an unknown device Waiting for root device /dev/mmcblk0p2...我所指的系統是遠端電腦（BeagleBoard-xM），通過串列電纜進行訪問。
我的問題是：
- 據我所知，
/dev/ttyO2代表/dev/console哪個是系統管理員控制台，但是這些是如何與引導程序互動的呢？換句話說，從console=ttyS2to的編輯console=ttyO2會影響啟動過程，還是只是為了通過終端仿真器啟用遠端人工互動？最後，開機失敗的原因是什麼？uEnv.txt是否正確？
console=ttyO2 允許您在相應的串列埠上查看核心和系統消息。否則它不會影響啟動過程 - 即使沒有控制台，系統也會啟動。
記得編輯
/etc/inittab- 將 ttyS2 更改為 ttyO2 以便在系統啟動後在串列控制台上獲得登錄提示。您的新核心可能缺少 SD 所需的驅動程序。檢查核心配置 - 將其與舊核心的配置進行比較。您需要將驅動程序編譯到核心中。
編輯：您的新核心未檢測到 SD。檢查它是否具有適合您的電路板的正確電路板配置。