BaiWfg22012-05-08 20:50

我是看到了您写的一本书：《嵌入式Linux开发详解》才来到了这里。还没看完，但我有一个很深的感觉就是：虽然写得不像有些书那样厚，但却告诉了读者应该到哪里去寻找相关知识，列出了很多经典书籍，这是我觉得很好的。也希望可以交流……

y3079214622010-02-07 01:17

经历竟是如此相似，小弟大三，对自己的嵌入式之路乱了手脚，看了你的每一页收获是如此之多，谢谢！

scott_lvsha2009-08-21 16:17

请教：我在arm上编译asterisk出问题，能不能帮我看一下啊，连接的时候出错 make[1]: Entering directory `/home/scott/asterisk-1.4.26/main' [LD] abstract_jb.o acl.o aescrypt.o aeskey.o aestab.o alaw.o app.o ast_expr2.o ast_expr2f.o asterisk.o astfd.o astmm.o astobj2.o audiohook.o autoservice.o callerid.o cdr.o channel.o chanvars.o cli.o config.o cryptostub.o db.o devicestate.o dial.o dns.o dnsmgr.o dsp.o enum.o file.o fixedjitterbuf.o frame.o fskmodem.o global_datastores.o http.o image.o indications.o io.o jitterbuf.o loader.o logger.o manager.o md5.o netsock.o pbx.o plc.o poll.o privacy.o rtp.o say.o sched.o sha1.o slinfactory.o srv.o stdtime/localtime.o strcompat.o tdd.o term.o threadstorage.o translate.o udptl.o ulaw.o utils.o editline/libedit.a db1-ast/libdb1.a -> asterisk astobj2.o: In function `ast_atomic_fetchadd_int': /home/scott/asterisk-1.4.26/include/asterisk/lock.h:1300: undefined reference to `__sync_fetch_and_add_4' /home/scott/asterisk-1.4.26/include/asterisk/lock.h:1300: undefined reference to `__sync_fetch_and_add_4' channel.o: In function `ast_atomic_fetchadd_int': /home/scott/asterisk-1.4.26/include/asterisk/lock.h:1300: undefined reference to `__sync_fetch_and_add_4' /home/scott/asterisk-1.4.26/include/asterisk/lock.h:1300: undefined reference to `__sync_fetch_and_add_4' dial.o: In function `ast_atomic_fetchadd_int': /home/scott/asterisk-1.4.26/include/asterisk/lock.h:1300: undefined reference to `__sync_fetch_and_add_4' manager.o: In function `ast_atomic_dec_and_test': /home/scott/asterisk-1.4.26/include/asterisk/lock.h:1346: undefined reference to `__sync_sub_and_fetch_4' /home/scott/asterisk-1.4.26/include/asterisk/lock.h:1346: undefined reference to `__sync_sub_and_fetch_4' /home/scott/asterisk-1.4.26/include/asterisk/lock.h:1346: undefined reference to `__sync_sub_and_fetch_4' /home/scott/asterisk-1.4.26/include/asterisk/lock.h:1346: undefined reference to `__sync_sub_and_fetch_4' /home/scott/asterisk-1.4.26/include/asterisk/lock.h:1346: undefined reference to `__sync_sub_and_fetch_4' utils.o:/home/scott/asterisk-1.4.26/include/asterisk/lock.h:1346: more undefined references to `__sync_sub_and_fetch_4' follow utils.o: In function `ast_atomic_fetchadd_int': /home/scott/asterisk-1.4.26/include/asterisk/lock.h:1300: undefined reference to `__sync_fetch_and_add_4' collect2: ld returned 1 exit status make[1]: *** [asterisk] Error 1

okti2009-04-04 09:35

我是菜鸟，与您交流，期待您的回复，如果有误请指正，okti@163.com

okti2009-04-04 09:32

与您交流：关于你的《基于at91rm9200重映射机制的修正》一文中，先判断是否已经重映射sram为0x0地址，之后再进行拷贝向量表，的疑问？？ 1.sram不论重映射前与后，都可以在0x20 0000地址可以访问到。所以，无论哪种情景，都可以将中断向量表直接拷贝到这个地址，无须作判断。 2. /*relocate exception table*/ /* 您要的是向量表的起始地址，可这是一个位置有关的代码,代码重定位之前应该不能正确访问,也就是说,掉电复位的情景应该无法实现*/ ldr r0, =_start /*应该将上面这条指令换成位置无关代码adr r0, _start*/ ldr r1, 0x0 /*将上面这个地址换成，0x20 0000 ldr r1,0x200000*/ mov r2, #16 copyex: >>>>>>>>>>>>>>>>>