編譯我自己的內核（不是來自linux內核源代碼）

Question

我從這里開始關注內核教程

我在編譯文件時遇到問題。

我嘗試編譯時遇到以下錯誤：

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確副本。
我可以看到在main.c中，函數的定義是這樣的

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

但在我的system.h文件中，它們的定義是這樣的

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

C不是我的主要語言，但我正在學習它，所以如果我的問題很簡單，我會道歉，但我認為這些定義應該是相同的嗎？

Answer 1

可能你的問題是size_t與平台上的int ，或者根本沒有正確指定size_t 。 指針類型應該沒問題（從技術上講，它們也應該匹配，但在大多數系統上sizeof(char*) == sizeof(void*) ）。

如果您正在開發自己的內核，那么您需要編寫自己的system.h 。 如果您正在編寫system.h和main.c ，那么您可以根據需要將它們匹配起來。 如果您查看本教程的這一頁 ，您會看到標題和C源都將memcpy聲明為：

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

但是，如果您在本教程結束時下載示例源文件，則會發現它是：

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

查看該文件的頂部，您會找到以下注釋：

/* 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. */

它看起來並不像您正在嘗試遵循教程，而是您嘗試從教程中剪切和粘貼代碼。 這就像試圖通過跟隨書中學習進行腦部手術一樣。 你可能會讓它發揮作用，但如果你真的不明白你在做什么......好吧，請幫助世界，不要把它用於任何關鍵的事情。

Answer 2

在main.c上的每個方法定義中用size替換size_t