19 lines
822 B
C
19 lines
822 B
C
void mainentry() {
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int x = 5;
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char* video_memory = (char*) 0xb8000;
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*video_memory = 'X';
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// Here , the star following the type means that this is not a variable to hold
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// a char (i.e. a single byte ) but a pointer to the ADDRESS of a char ,
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// which , being an address , will actually require the allocation of at least
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// 32 bits .
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char * video_address = (char*)(0xb8000);
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// If we ’d like to store a character at the address pointed to , we make the
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// assignment with a star - prefixed pointer variable . This is known as
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// dereferencing a pointer , because we are not changing the address held by
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// the pointer variable but the contents of that address .
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*video_address = 'x';
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// Just to emphasise the purpose of the star , an ommision of it , such as:
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}
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