uboot环境变量与内核MTD分区关系

                        Format: [,[,..]]

        dmasound=       [HW,OSS] Sound subsystem buffers

        dscc4.setup=    [NET]

        dtc3181e=       [HW,SCSI]

        earlyprintk=    [IA-32,X86-64]

                        earlyprintk=vga

                        earlyprintk=serial[,ttySn[,baudrate]]

                        Append ',keep' to not disable it when the real console

                        takes over.

                        Only vga or serial at a time, not both.

                        Currently only ttyS0 and ttyS1 are supported.

                        Interaction with the standard serial driver is not

                        very good.

                        The VGA output is eventually overwritten by the real

                        console.

        eata=           [HW,SCSI]

        eda=            [HW,PS2]

        edb=            [HW,PS2]

        edd=            [EDD]

                        Format: {'of[f]' | 'sk[ipmbr]'}

                        See comment in arch/i386/boot/edd.S

        eicon=          [HW,ISDN]

                        Format: ,,

        eisa_irq_edge=  [PARISC,HW]

                        See header of drivers/parisc/eisa.c.

        elanfreq=       [IA-32]

                        See comment before function elanfreq_setup() in

                        arch/i386/kernel/cpu/cpufreq/elanfreq.c.

        elevator=       [IOSCHED]

                        Format: {'as' | 'cfq' | 'deadline' | 'noop'}

                        See Documentation/block/as-iosched.txt and

                        Documentation/block/deadline-iosched.txt for details.

        elfcorehdr=     [IA-32]

                        Specifies physical address of start of kernel core

                        image elf header.

                        See Documentation/kdump.txt for details.

        enforcing       [SELINUX] Set initial enforcing status.

                        Format: {'0' | '1'}

                        See security/selinux/Kconfig help text.

                        0 -- permissive (log only, no denials).

                        1 -- enforcing (deny and log).

                        Default value is 0.

                        Value can be changed at runtime via /selinux/enforce.

        es1370=         [HW,OSS]

                        Format: [,]

                        See also header of sound/oss/es1370.c.

        es1371=         [HW,OSS]

                        Format: ,[,[]]

                        See also header of sound/oss/es1371.c.

        ether=          [HW,NET] Ethernet cards parameters

                        This option is obsoleted by the 'netdev=' option, which

                        has equivalent usage. See its documentation for details.

        eurwdt=         [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.

                        Format: [,]

        fd_mcs=         [HW,SCSI]

                        See header of drivers/scsi/fd_mcs.c.

        fdomain=        [HW,SCSI]

                        See header of drivers/scsi/fdomain.c.

        floppy=         [HW]

                        See Documentation/floppy.txt.

        ftape=          [HW] Floppy Tape subsystem debugging options.

                        See Documentation/ftape.txt.

        gamecon.map[2|3]=

                        [HW,JOY] Multisystem joystick and NES/SNES/PSX pad

                        support via parallel port (up to 5 devices per port)

                        Format: ,,,,,

                        See also Documentation/input/joystick-parport.txt

        gamma=          [HW,DRM]

        gdth=           [HW,SCSI]

                        See header of drivers/scsi/gdth.c.

        gpt             [EFI] Forces disk with valid GPT signature but

                        invalid Protective MBR to be treated as GPT.

        gscd=           [HW,CD]

                        Format:

        gt96100eth=     [NET] MIPS GT96100 Advanced Communication Controller

        gus=            [HW,OSS]

                        Format: ,,,

        gvp11=          [HW,SCSI]

        hashdist=       [KNL,NUMA] Large hashes allocated during boot

                        are distributed across NUMA nodes.  Defaults on

                        for IA-64, off otherwise.

                        Format: 0 | 1 (for off | on)

        hcl=            [IA-64] SGI's Hardware Graph compatibility layer

        hd=             [EIDE] (E)IDE hard drive subsystem geometry

                        Format: ,,

        hd?=            [HW] (E)IDE subsystem

        hd?lun=         See Documentation/ide.txt.

        highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact

                        size of . This works even on boxes that have no

                        highmem otherwise. This also works to reduce highmem

                        size on bigger boxes.

        hisax=          [HW,ISDN]

                        See Documentation/isdn/README.HiSax.