Rev 1618 |
Blame |
Compare with Previous |
Last modification |
View Log
| RSS feed
/* Project: OSLib
* Description: The OS Construction Kit
* Date: 1.6.2000
* Idea by: Luca Abeni & Gerardo Lamastra
*
* OSLib is an SO project aimed at developing a common, easy-to-use
* low-level infrastructure for developing OS kernels and Embedded
* Applications; it partially derives from the HARTIK project but it
* currently is independently developed.
*
* OSLib is distributed under GPL License, and some of its code has
* been derived from the Linux kernel source; also some important
* ideas come from studying the DJGPP go32 extender.
*
* We acknowledge the Linux Community, Free Software Foundation,
* D.J. Delorie and all the other developers who believe in the
* freedom of software and ideas.
*
* For legalese, check out the included GPL license.
*/
/* The OSLib (flat space) <-> Phisical address conversion */
#include <ll/i386/hw-func.h>
#include <ll/i386/mem.h>
FILE(X-Conv);
/* Conversion between PM address space & phisical address space */
/* If we do not support paging we need to relocate the .ELF executable */
/* using the segment register; however we also need to access all the */
/* phisical memory; for example if we allocate some memory (phisical) */
/* and we use a pointer to access that memory, the pointer will use */
/* the current DS to address the specified offset; but the phisical */
/* offset cannot be used because the base of DS is not zero as required */
/* to access phisical memory; the DS base is stored by X into the */
/* exec_base field of _X_info! This is the key to traslate ELF address */
/* into phisical address & viceversa */
/*
DWORD appl2linear(void *p)
{
unsigned long result;
result = (DWORD)(p) + _X_info->exec_base;
return(result);
}
void *linear2appl(DWORD a)
{
void *p;
if (a < _X_info->exec_base) p = NULL;
else p = (void *)(a-_X_info->exec_base);
return(p);
}
*/
LIN_ADDR addr2linear(unsigned short seg,unsigned long offset)
{
LIN_ADDR flatbase;
flatbase = (LIN_ADDR)GDT_read(seg,NULL,NULL,NULL);
return(flatbase + offset);
}