Uboot_readme中文注释版.rar

Uboot_readme中文注释版

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前面是Uboot的发展，下载地址，如何获得帮助，以及版本说明

Directory Hierarchy:
目录层次
====================

- board  Board dependent files
          开发板相关文件
- common Misc architecture independent functions
          多体系结构独立函数
- cpu    CPU specific files
          CPU相关文件
  - 74xx_7xx   Files specific to Freescale MPC74xx and 7xx CPUs
               Freescale MPC74XX的CPU相关文件
  - arm720t     Files specific to ARM 720 CPUs
                ARM720相关文件
  - arm920t     Files specific to ARM 920 CPUs
                ARM920相关文件
  - at91rm9200  Files specific to Atmel AT91RM9200 CPU
                AT91RM9200相关
  - imx       Files specific to Freescale MC9328 i.MX CPUs
              Freescale i.MX相关
  - s3c24x0   Files specific to Samsung S3C24X0 CPUs
  - arm925t   Files specific to ARM 925 CPUs
  - arm926ejs Files specific to ARM 926 CPUs
  - arm1136   Files specific to ARM 1136 CPUs
  - at32ap   Files specific to Atmel AVR32 AP CPUs
  - i386     Files specific to i386 CPUs
  - ixp      Files specific to Intel XScale IXP CPUs
  - leon2     Files specific to Gaisler LEON2 SPARC CPU
  - leon3     Files specific to Gaisler LEON3 SPARC CPU
  - mcf52x2   Files specific to Freescale ColdFire MCF52x2 CPUs
  - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
  - mcf532x   Files specific to Freescale ColdFire MCF5329 CPUs
  - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
  - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
  - mips Files specific to MIPS CPUs
  - mpc5xx Files specific to Freescale MPC5xx  CPUs
  - mpc5xxx Files specific to Freescale MPC5xxx CPUs
  - mpc8xx Files specific to Freescale MPC8xx  CPUs
  - mpc8220 Files specific to Freescale MPC8220 CPUs
  - mpc824x Files specific to Freescale MPC824x CPUs
  - mpc8260 Files specific to Freescale MPC8260 CPUs
  - mpc85xx Files specific to Freescale MPC85xx CPUs
  - nios Files specific to Altera NIOS CPUs
  - nios2 Files specific to Altera Nios-II CPUs
  - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
  - pxa  Files specific to Intel XScale PXA CPUs
  - s3c44b0 Files specific to Samsung S3C44B0 CPUs
  - sa1100 Files specific to Intel StrongARM SA1100 CPUs
- disk  Code for disk drive partition handling
          磁盘驱动，及分区操作的代码
- doc    Documentation (don't expect too much)
          文档（不要期待太多（搞不懂为什么了?））
- drivers Commonly used device drivers
          通用设备驱动
- dtt    Digital Thermometer and Thermostat drivers
          数字温度器及调温装置驱动
- examples Example code for standalone applications, etc.
            独立应用程序的例子
- include   Header Files
            头文件
- lib_arm   Files generic to ARM  architecture
            ARM体系结构通用的文件
- lib_avr32 Files generic to AVR32  architecture
- lib_generic Files generic to all  architectures
              所有体系结构通用的文件
- lib_i386 Files generic to i386  architecture
- lib_m68k Files generic to m68k  architecture
- lib_mips Files generic to MIPS  architecture
- lib_nios Files generic to NIOS  architecture
- lib_ppc Files generic to PowerPC architecture
- lib_sparc Files generic to SPARC  architecture
- libfdt Library files to support flattened device trees
          支持平板设备树的库文件
- net  Networking code
         网络代码
- post  Power On Self Test
          上电自检
- rtc  Real Time Clock drivers
          实时时钟驱动
- tools  Tools to build S-Record or U-Boot images, etc.
          编译S-Record和U-Boot镜像的工具
- api
          1.3版本的UBOOT还增加了一个API的文件夹，
          这里放的是一些扩展应用的独立的API函数
         
Software Configuration:
软件配置：
=======================

Configuration is usually done using C preprocessor defines; the
rationale behind that is to avoid dead code whenever possible.
配置是通过C预处理程序完成。

There are two classes of configuration variables:
有两类配置变量：

* Configuration _OPTIONS_:
  配置选项：
  These are selectable by the user and have names beginning with
  "CONFIG_".
  是可由用户选择并以“CONFIG_”开头

* Configuration _SETTINGS_:
  配置设置
  These depend on the hardware etc. and should not be meddled with if
  you don't know what you're doing; they have names beginning with
  "CFG_".
  依赖于硬件，由“CFG_”开头

Later we will add a configuration tool - probably similar to or even
identical to what's used for the Linux kernel. Right now, we have to
do the configuration by hand, which means creating some symbolic
links and editing some configuration files. We use the TQM8xxL boards
as an example here.
以后我们将加入类似Linux内核一样的配置工具。但现在只能手工配置。
我们将以TQM8XXL为例。

第一步：
Selection of Processor Architecture and Board Type:
选择处理器架构和板类型：
---------------------------------------------------

For all supported boards there are ready-to-use default
configurations available; just type "make _config".
对所有已至此的板都已经有可用的默认配置，只要执行：
make _config

下面是例子
Example: For a TQM823L module type:

 cd u-boot
 make TQM823L_config

For the Cogent platform, you need to specify the CPU type as well;
e.g. "make cogent_mpc8xx_config". And also configure the cogent
directory according to the instructions in cogent/README.
对于加强型平台还要指定CPU类型，请阅读cogent/READM

第二步
Configuration Options:
配置选项：
----------------------

Configuration depends on the combination of board and CPU type; all
such information is kept in a configuration file
配置依赖于板和CPU，所有配置设置信息保存在：
"include/configs/.h".

Example: For a TQM823L module, all configuration settings are in
"include/configs/TQM823L.h".

Many of the options are named exactly as the corresponding Linux
kernel configuration options. The intention is to make it easier to
build a config tool - later.

The following options need to be configured:
以下的选项需要被配置：
这里MPC的配置比较多，如果是SMDK2410的话配置会少很多

- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
CPU类型：正确地定义一个种类，比如：CONFIG_MPC85XX

- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
板类型：比如：CONFIG_MPC8540ADS

- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
  Define exactly one, e.g. CONFIG_ATSTK1002
CPU子类

- CPU Module Type: (if CONFIG_COGENT is defined)
  Define exactly one of
  CONFIG_CMA286_60_OLD
CPU模型
--- FIXME --- not tested yet:
  CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
  CONFIG_CMA287_23, CONFIG_CMA287_50

- Motherboard Type: (if CONFIG_COGENT is defined)
  Define exactly one of
  CONFIG_CMA101, CONFIG_CMA102
主板

- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
  Define one or more of
  CONFIG_CMA302
主板I/O模式

- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
  Define one or more of
  CONFIG_LCD_HEARTBEAT - update a character position on
       the LCD display every second with
       a "rotator" |\-/|\-/

- Board flavour: (if CONFIG_MPC8260ADS is defined)
  CONFIG_ADSTYPE
  Possible values are:
   CFG_8260ADS - original MPC8260ADS
   CFG_8266ADS - MPC8266ADS
   CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
   CFG_8272ADS - MPC8272ADS

- MPC824X Family Member (if CONFIG_MPC824X is defined)
  Define exactly one of
  CONFIG_MPC8240, CONFIG_MPC8245

- 8xx CPU Options: (if using an MPC8xx CPU)
  CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
       get_gclk_freq() cannot work
       e.g. if there is no 32KHz
       reference PIT/RTC clock
  CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
       or XTAL/EXTAL)

- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
  CFG_8xx_CPUCLK_MIN
  CFG_8xx_CPUCLK_MAX
  CONFIG_8xx_CPUCLK_DEFAULT
   See doc/README.MPC866

  CFG_MEASURE_CPUCLK

  Define this to measure the actual CPU clock instead
  of relying on the correctness of the configured
  values. Mostly useful for board bringup to make sure
  the PLL is locked at the intended frequency. Note
  that this requires a (stable) reference clock (32 kHz
  RTC clock or CFG_8XX_XIN)

- Intel Monahans options:
  CFG_MONAHANS_RUN_MODE_OSC_RATIO

  Defines the Monahans run mode to oscillator
  ratio. Valid values are 8, 16, 24, 31. The core
  frequency is this value multiplied by 13 MHz.

  CFG_MONAHANS_TURBO_RUN_MODE_RATIO

  Defines the Monahans turbo mode to oscillator
  ratio. Valid values are 1 (default if undefined) and
  2. The core frequency as calculated above is multiplied
  by this value.

- Linux Kernel Interface:
- Linux内核接口
  CONFIG_CLOCKS_IN_MHZ

  U-Boot stores all clock information in Hz
  internally.
       UBOOT以Hz位单位存储时钟信息
For binary compatibility with older Linux
  kernels (which expect the clocks passed in the
  bd_info data to be in MHz
Linux内核期望时钟是以MHz位单位传到bd_info的)
the environment variable
为了和内核兼容可以定义环境变量
  "clocks_in_mhz" can be defined so that U-Boot
  converts clock data to MHZ before passing it to the
  Linux kernel.
       把UBOOT的时钟数据转换位MHz后传入内核
  When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
  "clocks_in_mhz=1" is automatically included in the
  default environment.
       当CONFIG_CLOCKS_IN_MHZ被定义后clocks_in_mhz=1
会被自动包含到环境中

  CONFIG_MEMSIZE_IN_BYTES  [relevant for MIPS only]
       只跟MIPS相关

  When transferring memsize parameter to linux, some versions
  expect it to be in bytes, others in MB.
  Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
       对于内存大小的参数可以定义CONFIG_MEMSIZE_IN_BYTES
       以BYTES位单位

  CONFIG_OF_LIBFDT

  New kernel versions are expecting firmware settings to be
  passed using flattened device trees (based on open firmware
  concepts).

  CONFIG_OF_LIBFDT
   * New libfdt-based support
   * Adds the "fdt" command
   * The bootm command automatically updates the fdt

  OF_CPU - The proper name of the cpus node.
  OF_SOC - The proper name of the soc node.
  OF_TBCLK - The timebase frequency.
  OF_STDOUT_PATH - The path to the console device

  boards with QUICC Engines require OF_QE to set UCC MAC
  addresses

  CONFIG_OF_BOARD_SETUP

  Board code has addition modification that it wants to make
  to the flat device tree before handing it off to the kernel

  CONFIG_OF_BOOT_CPU

  This define fills in the correct boot CPU in the boot
  param header, the default value is zero if undefined.

- Serial Ports:
- 串口
  CFG_PL010_SERIAL

  Define this if you want support for Amba PrimeCell PL010 UARTs.
       要支持Amba PrimeCell PL010 UARTs就定义此项

  CFG_PL011_SERIAL

  Define this if you want support for Amba PrimeCell PL011 UARTs.

  CONFIG_PL011_CLOCK

  If you have Amba PrimeCell PL011 UARTs, set this variable to
  the clock speed of the UARTs.

  CONFIG_PL01x_PORTS

  If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
  define this to a list of base addresses for each (supported)
  port. See e.g. include/configs/versatile.h

- Console Interface:
- 控制台接口
  Depending on board, define exactly one serial port
  (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
  CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
  console by defining CONFIG_8xx_CONS_NONE
       依赖于板，定义一个串口

  Note: if CONFIG_8xx_CONS_NONE is defined, the serial
  port routines must be defined elsewhere
  (i.e. serial_init(), serial_getc(), ...)