编译我自己的内核(不是来自linux内核源代码)

Question

我从这里开始关注内核教程

我在编译文件时遇到问题.

我尝试编译时遇到以下错误:

main.c:8: error: expected declaration specifiers or ‘...’ before ‘size_t’
main.c:8: error: conflicting types for ‘memcpy’                          
./include/system.h:5: note: previous declaration of ‘memcpy’ was here    
main.c: In function ‘memcpy’:                                            
main.c:12: error: ‘count’ undeclared (first use in this function)        
main.c:12: error: (Each undeclared identifier is reported only once      
main.c:12: error: for each function it appears in.)                      
main.c: At top level:                                                    
main.c:16: error: expected declaration specifiers or ‘...’ before ‘size_t’
main.c:16: error: conflicting types for ‘memset’
./include/system.h:6: note: previous declaration of ‘memset’ was here
main.c: In function ‘memset’:
main.c:19: error: ‘count’ undeclared (first use in this function)
main.c: At top level:
main.c:23: error: expected declaration specifiers or ‘...’ before ‘size_t’
main.c:23: error: conflicting types for ‘memsetw’
./include/system.h:7: note: previous declaration of ‘memsetw’ was here
main.c: In function ‘memsetw’:
main.c:26: error: ‘count’ undeclared (first use in this function)
main.c: At top level:
main.c:30: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘strlen’
main.c:49: warning: return type of ‘main’ is not ‘int’
main.c: In function ‘main’:
main.c:64: warning: pointer targets in passing argument 1 of ‘puts’ differ in    signedness
./include/system.h:13: note: expected ‘unsigned char *’ but argument is of type ‘char *’
main.c:51: warning: unused variable ‘i’
scrn.c: In function ‘scroll’:
scrn.c:24: warning: passing argument 1 of ‘memcpy’ from incompatible pointer type
./include/system.h:5: note: expected ‘unsigned char *’ but argument is of type ‘short unsigned int *’
scrn.c:24: warning: passing argument 2 of ‘memcpy’ from incompatible pointer type
./include/system.h:5: note: expected ‘const unsigned char *’ but argument is of type  ‘short unsigned int *’
scrn.c: In function ‘puts’:
scrn.c:139: warning: pointer targets in passing argument 1 of ‘strlen’ differ in signedness
./include/system.h:8: note: expected ‘const char *’ but argument is of type ‘unsigned char *’

我的文件是教程中的文件的精确副本.
我可以看到在main.c中,函数的定义是这样的

void *memcpy(void *dest,const void *src, size_t count)

但在我的system.h文件中,它们的定义是这样的

extern unsigned char *memcpy(unsigned char *dest,const unsigned char *src, int count)

C不是我的主要语言,但我正在学习它,所以如果我的问题很简单,我会道歉,但我认为这些定义应该是一样的吗？

Answer 1

可能您的问题size_t与int您的平台上的问题不同,或者size_t根本没有正确指定.指针类型应该没问题(从技术上讲,它们也应匹配,但在大多数系统上sizeof(char*) == sizeof(void*)).

如果您正在开发自己的内核,那么您需要编写自己的内核system.h.如果你正在写两system.h和main.c,你可以让他们匹配,但是你会喜欢.如果您查看本教程的这一页,您会看到标题和C源都声明memcpy为:

unsigned char *memcpy(unsigned char *dest, const unsigned char *src, int count);

但是,如果您在本教程结束时下载示例源文件,则会发现它是:

void *memcpy(void *dest, const void *src, size_t count);

查看该文件的顶部,您会找到以下注释:

/* bkerndev - Bran's Kernel Development Tutorial
*  By:   Brandon F. (friesenb@gmail.com)
*  Desc: Main.c: C code entry.
*
*  Notes: No warranty expressed or implied. Use at own risk. */

它看起来并不像您正在尝试遵循教程,而是您尝试从教程中剪切和粘贴代码.这就像试图通过跟随书中学习进行脑部手术一样.你可能会让它发挥作用,但如果你真的不明白你在做什么......好吧,请帮助世界,不要把它用于任何关键的事情.