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/*
* mjs copyright
*/
/*
* Obtain memory configuration information from the BIOS
*
* Note that we don't try too hard here; knowing the size of
* base memory and extended memory out to 16 or 64M is enough for
* the requirements of the bootstrap.
*
* We also maintain a pointer to the top of physical memory
* once called to allow rangechecking of load/copy requests.
*/
#include <stand.h>
#include "btxv86.h"
vm_offset_t memtop;
/*
* Return base memory size in kB.
*/
int
getbasemem(void)
{
#ifdef PC98
return ((*(u_char *)PTOV(0xA1501)&0x07)+1)*128;
#else
v86.ctl = 0;
v86.addr = 0x12; /* int 0x12 */
v86int();
return(v86.eax & 0xffff);
#endif
}
/*
* Return extended memory size in kB
*/
int
getextmem(void)
{
int extkb;
#ifdef PC98
extkb = *(u_char *)PTOV(0xA1401)*128 + *(unsigned short *)PTOV(0xA1594)*1024;
#else
v86.ctl = 0;
v86.addr = 0x15; /* int 0x15 function 0x88*/
v86.eax = 0x8800;
v86int();
extkb = v86.eax & 0xffff;
#endif
/* Set memtop to actual top or 16M, whicheve is less */
memtop = min((0x100000 + (extkb * 1024)), (16 * 1024 * 1024));
return(extkb);
}
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