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Hey Guys This might be kind of silly question but i don't understand this code segment: ==================================================== //our first page table comes right after the page directory unsigned int *first_page_table = page_directory + 0x1000; // holds the physical address where we want to start mapping these pages to. // in this case, we want to map these pages to the very beginning of memory. unsigned int address = 0; unsigned int i; //we will fill all 1024 entries, mapping 4 megabytes for(i = 0; i < 1024; i++) { first_page_table[i] = address | 3; // attributes: supervisor level, read/write, present. address = address + 4096; //advance the address to the next page boundary } ================================================== This is taken of: http://wiki.osdev.org/Setting_Up_Paging Been working at a small os project of my own: http://gitorious.org/projects/zepher For something in my spare time, starting to love gnu as. Anyways the thing i don't understand is: first_page_table[i] = address | 3; I don't know what this does. first_page_table was it not just an integer? Or does this go trough each byte in the int and set rights? with the '|' like value address and rights 3 or something. I haven't really seen this syntax so sorry if it sounds really stupid! One more thing is there some documentation on the __atribute__ system in gcc i have set some structs to be packed, is there some more documentation to see what other modes gcc supports for data types? Thanks -Phil http://redbrain.co.uk
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