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- /*
- * librm: a library for interfacing to real-mode code
- *
- * Michael Brown <mbrown@fensystems.co.uk>
- *
- */
-
- #include <stdint.h>
- #include <librm.h>
-
- /*
- * This file provides functions for managing librm.
- *
- */
-
- /**
- * Allocate space on the real-mode stack and copy data there from a
- * user buffer
- *
- * @v data User buffer
- * @v size Size of stack data
- * @ret sp New value of real-mode stack pointer
- */
- uint16_t copy_user_to_rm_stack ( userptr_t data, size_t size ) {
- userptr_t rm_stack;
- rm_sp -= size;
- rm_stack = real_to_user ( rm_ss, rm_sp );
- memcpy_user ( rm_stack, 0, data, 0, size );
- return rm_sp;
- };
-
- /**
- * Deallocate space on the real-mode stack, optionally copying back
- * data to a user buffer.
- *
- * @v data User buffer
- * @v size Size of stack data
- */
- void remove_user_from_rm_stack ( userptr_t data, size_t size ) {
- if ( data ) {
- userptr_t rm_stack = real_to_user ( rm_ss, rm_sp );
- memcpy_user ( rm_stack, 0, data, 0, size );
- }
- rm_sp += size;
- };
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