嵌入式ARM linux系统如何设置开机启动应用程序?

其实楼主的问题很专业，之前我在周立功那边也了解过不少。\x0d\x0a 当用户需要EasyARM-iMX283在开机启动后就运行指定的应用程序或指令时，可以通过vi命令编辑/etc/rc.d/init.d/start_userapp，将要执行的指令添加到里面。若用户有一个hellow的程序放在/home/目录中，那么设置hellow程序开机启动的方法如程序清单 1.1红色部分所示。\x0d\x0a程序清单1.1 用户启动文件\x0d\x0a#!/bin/sh \x0d\x0a#you can add your app start_command three \x0d\x0a/home/hellow \x0d\x0a#start qt command,you can delete it 下面是启动QT界面的指令，若用户不需要启动QT，可以直接删除\x0d\x0aexport TSLIB_PLUGINDIR=/usrb/ts/ \x0d\x0aexport TSLIB_CONFFILE=/etc/ts.conf \x0d\x0aexport TSLIB_TSDEVICE=/dev/input/ts0 \x0d\x0aexport TSLIB_CALIBFILE=/etc/pointercal \x0d\x0aexport QT_QWS_FONTDIR=/usrb/fonts\x0d\x0aexport QWS_MOUSE_PROTO=Tslib:/dev/input/ts0 \x0d\x0a/usr/zhiyuan/zylauncher/start_zylauncher &\x0d\x0a\x0d\x0a如果程序是一个阻塞程序（程序被运行后不会退出或返回），则可能会导致位于其后的指令或程序无法得到执行，并且始终占用串口终端，造成其他程序（比如Shell）无法通过串口终端与用户交互。对于此类应用程序，可以在其后面添加“ &”（注意：是“空格”+“&”符号）让其在后台运行，如下所示：\x0d\x0a/home/hellow &

1. 内核启动地址

ZTEXTADDR

解压代码运行的开始地址。没有物理地址和虚拟地址之分，因为此时MMU处于关闭状态。这个地址不一定时RAM的地址，可以是支持读写寻址的flash等存储中介。

Start address of decompressor. here's no point in talking about virtual or physical addresses here, since the MMU will be off at the time when you call the decompressor code. You normally call the kernel at this address to start it booting. This doesn't have to be located in RAM, it can be in flash or other read-only or read-write addressable medium.

在arch/arm/boot/compressed/Makefile中说的很明确

#

# We now have a PIC decompressor implementation. Decompressors running

# from RAM should not define ZTEXTADDR. Decompressors running directly

# from ROM or Flash must define ZTEXTADDR (preferably via the config)

# FIXME: Previous assignment to ztextaddr-y is lost here. See SHARK

ifeq ($(CONFIG_ZBOOT_ROM),y)

ZTEXTADDR := $(CONFIG_ZBOOT_ROM_TEXT)

ZBSSADDR:= $(CONFIG_ZBOOT_ROM_BSS)

else

ZTEXTADDR := 0

ZBSSADDR:= ALIGN(8)

endif

ZRELADDR

内核启动在RAM中的地址。压缩的内核映像被解压到这个地址，然后执行。

This is the address where the decompressed kernel will be written, and eventually executed. The following constraint must be valid:

__virt_to_phys(TEXTADDR) == ZRELADDR

The initial part of the kernel is carefully coded to be position independent.

一般定义在项目目录下，比如：

arch/arm/mach-at91/Makefile.boot: zreladdr-y += 0x70008000

arch/arm/mach-at91/Makefile.boot: zreladdr-y += 0x20008000

arch/arm/mach-cns3xxx/Makefile.boot: zreladdr-y += 0x00008000

arch/arm/mach-davinci/Makefile.boot: zreladdr-y += 0xc0008000

arch/arm/mach-davinci/Makefile.boot: zreladdr-y += 0x80008000

arch/arm/mach-dove/Makefile.boot: zreladdr-y += 0x00008000

arch/arm/mach-ebsa110/Makefile.boot: zreladdr-y += 0x00008000

arch/arm/mach-exynos/Makefile.boot: zreladdr-y += 0x40008000

arch/arm/mach-footbridge/Makefile.boot: zreladdr-y += 0x00008000

arch/arm/mach-gemini/Makefile.boot: zreladdr-y += 0x00008000

arch/arm/mach-gemini/Makefile.boot: zreladdr-y += 0x10008000

arch/arm/mach-integrator/Makefile.boot: zreladdr-y += 0x00008000

arch/arm/mach-iop13xx/Makefile.boot: zreladdr-y += 0x00008000

在arch/arm/boot/Makefile中被赋值：

ZRELADDR := $(zreladdr-y)

PARAMS_PHYS := $(params_phys-y)

INITRD_PHYS := $(initrd_phys-y)

... ...

ifneq ($(LOADADDR),)

UIMAGE_LOADADDR=$(LOADADDR)

else

ifeq ($(CONFIG_ZBOOT_ROM),y)

UIMAGE_LOADADDR=$(CONFIG_ZBOOT_ROM_TEXT)

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