机器组织与汇编语言设计Machine-Organization-and-Assembly...-精选版.ppt

5.1 strip symbols $strip test2; $ls – l test2 -rwxr-xr-x 1 root src 546 Jan 6 21:46 test2 $strip --remove-section=.comment --remove-section=.note test2 $ls – l test2 -rwxr-xr-x 1 root src 432 Jan 6 21:47 test2 $strip --remove-section=.data --remove-section=.sbss --remove-section=.bss test2 $ls – l test2 -rwxr-xr-x 1 root src 344 Jan 6 21:48 test2 * 基本内容 By gaining a deeper understanding of how computers work, the reader can often be much more productive developing software in higher level languages such as C and C++. Learning to program in assembly language is an excellent way to achieve this goal. Learning assembler in Linux environment. * gnu [简明英汉词典] [nu:, nju:] n.角马(南非产的象牛的大羚羊) / Welcome to the GNU Project web server, . The GNU Project was launched in 1984 to develop a complete Unix-like operating system which is free software: the GNU system. (GNU is a recursive acronym for ``GNUs Not Unix; it is pronounced guh-NEW.) Variants of the GNU operating system, which use the kernel Linux, are now widely used; though these systems are often referred to as ``Linux, they are more accurately called GNU/Linux systems. * In addition to this text and the software I provide, you will need a machine running Linux (preferably Linux 2.4 or later), “nasm” and “ld” (if you can compile GCC programs, you’ve got these, they come standard with most distributions), * ldd tells test0 depends on libc.so.6 (GNU libc6), and nm outputs so many unfamiliar symbols. We do not concern precise meanings of the symbols but care T main near at the bottom. This is the famous name we defined in the source. By the way, smart readers may notice that huge code size is related with these unknown symbols. Yes, thats right! * A startup file crt1.o contains a program whose entry point is _start and the code also includes main() calling statement (NOTE main entry is Undefined in crt1.o). So, the famous main() is implicitly called within crt1.o. Ill show you how to escape from the pr