編譯我自己的內核（而不是從Linux內核源）

Question

我從以下編譯我的文件here

的具有1M的問題內核教程。

我碰到下面的錯誤，當我試圖編譯：

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 *’ 

我的文件是從教程中的的精確副本。
我可以看到，在main.c中的函數定義，像這樣

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

但在我system.h中文件它們像這樣

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

C中定義不是我主要的語言，但我正在學習它的過程中，所以我道歉，如果我的問題很簡單，但我會認爲這些定義應該是相同的？

Answer 1

可能是您的問題size_t與您的平臺上的int不一樣，或者size_t沒有正確指定。指針類型應該是OK的（技術上，它們也應該匹配，但是在大多數系統上sizeof(char*) == sizeof(void*)）。

如果您正在開發自己的內核，那麼您需要編寫自己的system.h。如果您同時編寫system.h和main.c，則可以根據需要將它們匹配起來。如果你看一下this page of the tutorial，你會看到標題和C源都聲明memcpy爲：

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

但是，如果你下載示例源文件在教程的最後，你會發現它是不是：

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

望着那文件的頂部，你會發現這樣的評論：

/* 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. */ 

它看起來並不像你想跟隨的教程，但RA那麼你試圖從教程中剪切和粘貼代碼。這就像試圖通過一本書一起學習進行腦部手術一樣。你可能會得到它的工作，但如果你真的不明白你在做什麼...好吧，請爲世界幫忙，不要用它來做任何關鍵的事情。

Answer 2

在每個方法定義爲int替換上的main.c