Uboot_readme中文注釋版

這是本人在網(wǎng)上搜集整理的，希望和我對大家能夠有幫助，希望大家不斷的將其完善，大家的改進(jìn)版希望能夠給我回發(fā)一份，感謝大家。

前面是Uboot的發(fā)展，下載地址，如何獲得幫助，以及版本說明

Directory Hierarchy:
目錄層次
====================

- board??Board dependent files
????????? 開發(fā)板相關(guān)文件
- common?Misc architecture independent functions
????????? 多體系結(jié)構(gòu)獨(dú)立函數(shù)
- cpu??? CPU specific files
????????? CPU相關(guān)文件
? - 74xx_7xx?? Files specific to Freescale MPC74xx and 7xx CPUs
? ???????????? Freescale MPC74XX的CPU相關(guān)文件
? - arm720t???? Files specific to ARM 720 CPUs
??????????????? ARM720相關(guān)文件
? - arm920t???? Files specific to ARM 920 CPUs
??????????????? ARM920相關(guān)文件
? - at91rm9200? Files specific to Atmel AT91RM9200 CPU
??????????????? AT91RM9200相關(guān)
? - imx?????? Files specific to Freescale MC9328 i.MX CPUs
????????????? Freescale i.MX相關(guān)
? - 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
????????? 磁盤驅(qū)動，及分區(qū)操作的代碼
- doc??? Documentation (don't expect too much)
????????? 文檔（不要期待太多（搞不懂為什么了?））
- drivers?Commonly used device drivers
????????? 通用設(shè)備驅(qū)動
- dtt??? Digital Thermometer and Thermostat drivers
????????? 數(shù)字溫度器及調(diào)溫裝置驅(qū)動
- examples?Example code for standalone applications, etc.
??????????? 獨(dú)立應(yīng)用程序的例子
- include?? Header Files
??????????? 頭文件
- lib_arm?? Files generic to ARM? architecture
??????????? ARM體系結(jié)構(gòu)通用的文件
- lib_avr32?Files generic to AVR32? architecture
- lib_generic?Files generic to all? architectures
????????????? 所有體系結(jié)構(gòu)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
????????? 支持平板設(shè)備樹的庫文件
- net??Networking code
???????? 網(wǎng)絡(luò)代碼
- post??Power On Self Test
????????? 上電自檢
- rtc??Real Time Clock drivers
????????? 實(shí)時時鐘驅(qū)動
- tools??Tools to build S-Record or U-Boot images, etc.
????????? 編譯S-Record和U-Boot鏡像的工具
- api
????????? 1.3版本的UBOOT還增加了一個API的文件夾，
????????? 這里放的是一些擴(kuò)展應(yīng)用的獨(dú)立的API函數(shù)
?????????
Software Configuration:
軟件配置：
=======================

Configuration is usually done using C preprocessor defines; the
rationale behind that is to avoid dead code whenever possible.
配置是通過C預(yù)處理程序完成。

There are two classes of configuration variables:
有兩類配置變量：

* Configuration _OPTIONS_:
? 配置選項(xiàng)：
? These are selectable by the user and have names beginning with
? "CONFIG_".
? 是可由用戶選擇并以“CONFIG_”開頭

* Configuration _SETTINGS_:
? 配置設(shè)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_".
? 依賴于硬件，由“CFG_”開頭

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.
以后我們將加入類似Linux內(nèi)核一樣的配置工具。但現(xiàn)在只能手工配置。
我們將以TQM8XXL為例。

第一步：
Selection of Processor Architecture and Board Type:
選擇處理器架構(gòu)和板類型：
---------------------------------------------------

For all supported boards there are ready-to-use default
configurations available; just type "make _config".
對所有已至此的板都已經(jīng)有可用的默認(rèn)配置，只要執(zhí)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.
對于加強(qiáng)型平臺還要指定CPU類型，請閱讀cogent/READM

第二步
Configuration Options:
配置選項(xiàng)：
----------------------

Configuration depends on the combination of board and CPU type; all
such information is kept in a configuration file
配置依賴于板和CPU，所有配置設(shè)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:
以下的選項(xiàng)需要被配置：
這里MPC的配置比較多，如果是SMDK2410的話配置會少很多

- CPU Type:?Define exactly one, e.g. CONFIG_MPC85XX.
CPU類型：正確地定義一個種類，比如：CONFIG_MPC85XX

- Board Type:?Define exactly one, e.g. CONFIG_MPC8540ADS.
板類型：比如：CONFIG_MPC8540ADS

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

- 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內(nèi)核接口
??CONFIG_CLOCKS_IN_MHZ

??U-Boot stores all clock information in Hz
??internally.
?????? UBOOT以Hz位單位存儲時鐘信息
For binary compatibility with older Linux
??kernels (which expect the clocks passed in the
??bd_info data to be in MHz
Linux內(nèi)核期望時鐘是以MHz位單位傳到bd_info的)
the environment variable
為了和內(nèi)核兼容可以定義環(huán)境變量
??"clocks_in_mhz" can be defined so that U-Boot
??converts clock data to MHZ before passing it to the
??Linux kernel.
?????? 把UBOOT的時鐘數(shù)據(jù)轉(zhuǎn)換位MHz后傳入內(nèi)核
??When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
??"clocks_in_mhz=1" is automatically included in the
??default environment.
?????? 當(dāng)CONFIG_CLOCKS_IN_MHZ被定義后clocks_in_mhz=1
會被自動包含到環(huán)境中

??CONFIG_MEMSIZE_IN_BYTES??[relevant for MIPS only]
?????? 只跟MIPS相關(guān)

??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.
?????? 對于內(nèi)存大小的參數(shù)可以定義CONFIG_MEMSIZE_IN_BYTES
?????? 以BYTES位單位

??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就定義此項(xiàng)

??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:
-?控制臺接口
??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
?????? 依賴于板，定義一個串口

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