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#include <core.h>
#include <com32.h>
#include <sys/io.h>
#include <fs.h>
#include <bios.h>
static uint32_t min_lowmem_heap = 65536;
extern char __lowmem_heap[];
uint8_t KbdFlags; /* Check for keyboard escapes */
__export uint8_t KbdMap[256]; /* Keyboard map */
__export uint16_t PXERetry;
static inline void check_escapes(void)
{
com32sys_t ireg, oreg;
ireg.eax.b[1] = 0x02; /* Check keyboard flags */
__intcall(0x16, &ireg, &oreg);
KbdFlags = oreg.eax.b[0];
/* Ctrl->skip 386 check */
if (!(oreg.eax.b[0] & 0x04)) {
/*
* Now check that there is sufficient low (DOS) memory
*
* NOTE: Linux doesn't use all of real_mode_seg, but we use
* the same segment for COMBOOT images, which can use all 64K.
*/
uint32_t mem;
__intcall(0x12, &ireg, &oreg);
mem = ((uint32_t)__lowmem_heap) + min_lowmem_heap + 1023;
mem = mem >> 10;
if (oreg.eax.w[0] < mem) {
char buf[256];
snprintf(buf, sizeof(buf),
"It appears your computer has only "
"%dK of low (\"DOS\") RAM.\n"
"This version of Syslinux needs "
"%dK to boot. "
"If you get this\nmessage in error, "
"hold down the Ctrl key while booting, "
"and I\nwill take your word for it.\n",
oreg.eax.w[0], mem);
writestr(buf);
kaboom();
}
}
}
extern uint32_t BIOS_timer_next;
extern uint32_t timer_irq;
static inline void bios_timer_init(void)
{
unsigned long next;
uint32_t *hook = (uint32_t *)BIOS_timer_hook;
next = *hook;
BIOS_timer_next = next;
*hook = (uint32_t)&timer_irq;
}
void init(com32sys_t *regs __unused)
{
int i;
/* Initialize timer */
bios_timer_init();
for (i = 0; i < 256; i++)
KbdMap[i] = i;
adjust_screen();
/* Init the memory subsystem */
mem_init();
dprintf("%s%s", syslinux_banner, copyright_str);
/* CPU-dependent initialization and related checks. */
check_escapes();
/*
* Scan the DMI tables for interesting information.
*/
dmi_init();
}
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