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- /* Etherboot routines for PCBIOS firmware.
- *
- * Body of routines taken from old pcbios.S
- */
-
- #include "stdint.h"
- #include "realmode.h"
-
- #define BIOS_DATA_SEG 0x0040
-
- #define CF ( 1 << 0 )
-
- /**************************************************************************
- CURRTICKS - Get Time
- Use direct memory access to BIOS variables, longword 0040:006C (ticks
- today) and byte 0040:0070 (midnight crossover flag) instead of calling
- timeofday BIOS interrupt.
- **************************************************************************/
- #if defined(CONFIG_TSC_CURRTICKS)
- #undef CONFIG_BIOS_CURRTICKS
- #else
- #define CONFIG_BIOS_CURRTICKS 1
- #endif
- #if defined(CONFIG_BIOS_CURRTICKS)
- unsigned long currticks ( void ) {
- static uint32_t days = 0;
- uint32_t ticks;
- uint8_t midnight;
-
- /* Re-enable interrupts so that the timer interrupt can occur
- */
- REAL_EXEC ( rm_currticks,
- "sti\n\t"
- "nop\n\t"
- "nop\n\t"
- "cli\n\t",
- 0,
- OUT_CONSTRAINTS (),
- IN_CONSTRAINTS (),
- CLOBBER ( "eax" ) ); /* can't have an empty clobber list */
-
- get_real ( ticks, BIOS_DATA_SEG, 0x006c );
- get_real ( midnight, BIOS_DATA_SEG, 0x0070 );
-
- if ( midnight ) {
- midnight = 0;
- put_real ( midnight, BIOS_DATA_SEG, 0x0070 );
- days += 0x1800b0;
- }
- return ( days + ticks );
- }
- #endif /* CONFIG_BIOS_CURRTICKS */
-
- /**************************************************************************
- CPU_NAP - Save power by halting the CPU until the next interrupt
- **************************************************************************/
- void cpu_nap ( void ) {
- REAL_EXEC ( rm_cpu_nap,
- "sti\n\t"
- "hlt\n\t"
- "cli\n\t",
- 0,
- OUT_CONSTRAINTS (),
- IN_CONSTRAINTS (),
- CLOBBER ( "eax" ) ); /* can't have an empty clobber list */
- }
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