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- #include "common.h"
- BEGIN
- CLEAR
- STAGE2
- PROTECTED_MODE
- SETUP_PAGING_4M
- /* Setup a test canary value. */
- movl $0x1234, 0x1000
- /* Print the canary to make sure it is really there. */
- VGA_PRINT_HEX_4 0x1000
- /* Make page 0 point to 4KiB. */
- orb $0x10, page_table + 1
- PAGING_ON
- /* THIS is what we've been working for!!!
- * Even though we mov to 0, the paging circuit reads that as physical address 0x1000,
- * so the canary value 0x1234 should be modified to 0x5678.
- **/
- movl $0x5678, 0
- /* Turn paging back off to prevent it from messing with us.
- * Remember that VGA does memory accesses, so if paging is still on,
- * we must identity map up to it, which we have, so this is not mandatory.
- * */
- PAGING_OFF
- /* Print the (hopefully) modified value 0x5678. */
- VGA_PRINT_HEX_4 0x1000
- jmp .
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