diff options
Diffstat (limited to 'arch/x86/lib/pcat_timer.c')
| -rw-r--r-- | arch/x86/lib/pcat_timer.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/lib/pcat_timer.c b/arch/x86/lib/pcat_timer.c index ce15818ec2..347cdda9f6 100644 --- a/arch/x86/lib/pcat_timer.c +++ b/arch/x86/lib/pcat_timer.c @@ -9,11 +9,21 @@ #include <asm/io.h> #include <asm/i8254.h> +#define TIMER1_VALUE 18 /* 15.6us */ #define TIMER2_VALUE 0x0a8e /* 440Hz */ int pcat_timer_init(void) { /* + * Initialize counter 1, used to refresh request signal. + * This is required for legacy purpose as some codes like + * vgabios utilizes counter 1 to provide delay functionality. + */ + outb(PIT_CMD_CTR1 | PIT_CMD_LOW | PIT_CMD_MODE2, + PIT_BASE + PIT_COMMAND); + outb(TIMER1_VALUE, PIT_BASE + PIT_T1); + + /* * Initialize counter 2, used to drive the speaker. * To start a beep, set both bit0 and bit1 of port 0x61. * To stop it, clear both bit0 and bit1 of port 0x61. |