diff options
Diffstat (limited to 'src/arch')
| -rw-r--r-- | src/arch/i386/firmware/pcbios/gateA20.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/src/arch/i386/firmware/pcbios/gateA20.c b/src/arch/i386/firmware/pcbios/gateA20.c index 5a27e7069..cdc866850 100644 --- a/src/arch/i386/firmware/pcbios/gateA20.c +++ b/src/arch/i386/firmware/pcbios/gateA20.c @@ -27,16 +27,17 @@ enum { Disable_A20 = 0x2400, Enable_A20 = 0x2401, Query_A20_Status = 0x2402, #define CF ( 1 << 0 ) #ifndef IBM_L40 -static void empty_8042 ( void ) -{ +static void empty_8042 ( void ) { unsigned long time; - char st; time = currticks() + TICKS_PER_SEC; /* max wait of 1 second */ - while ((((st = inb(K_CMD)) & K_OBUF_FUL) || - (st & K_IBUF_FUL)) && - currticks() < time) - inb(K_RDWR); + while ( ( inb ( K_CMD ) & K_IBUF_FUL ) && + currticks() < time ) { + /* Do nothing. In particular, do *not* read from + * K_RDWR, because that will drain the keyboard buffer + * and lose keypresses. + */ + } } #endif /* IBM_L40 */ @@ -66,6 +67,7 @@ void gateA20_set ( void ) { : "=r" ( flags ), "=a" ( discard_a ) : "a" ( Enable_A20 ) ); + if ( flags & CF ) { /* INT 15 method failed, try alternatives */ #ifdef IBM_L40 @@ -78,7 +80,7 @@ void gateA20_set ( void ) { empty_8042(); #endif /* IBM_L40 */ } - + reentry_guard = 0; } |