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author | Bin Meng <bmeng.cn@gmail.com> | 2015-01-06 14:14:14 (GMT) |
---|---|---|
committer | Simon Glass <sjg@chromium.org> | 2015-01-13 15:25:02 (GMT) |
commit | 3ba6a0f4f6a2381ad32930df6277930a3de577bc (patch) | |
tree | 218fdbde4e70eeab4b65543757677b3ca5864229 /arch/x86/Kconfig | |
parent | 5c564b0d2fd108ebc5fd6bb0081b981ee32ddf0b (diff) | |
download | u-boot-3ba6a0f4f6a2381ad32930df6277930a3de577bc.tar.xz |
x86: Allow a hardcoded TSC frequency provided by Kconfig
By default U-Boot automatically calibrates TSC running frequency via
MSR and PIT. The calibration may not work on every x86 processor, so
a new Kconfig option CONFIG_TSC_CALIBRATION_BYPASS is introduced to
allow bypassing the calibration and assign a hardcoded TSC frequency
CONFIG_TSC_FREQ_IN_MHZ.
Normally the bypass should be turned on in a simulation environment
like qemu.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'arch/x86/Kconfig')
-rw-r--r-- | arch/x86/Kconfig | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index e992e64..ffcb4cb 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -313,6 +313,26 @@ config FRAMEBUFFER_VESA_MODE endmenu +config TSC_CALIBRATION_BYPASS + bool "Bypass Time-Stamp Counter (TSC) calibration" + default n + help + By default U-Boot automatically calibrates Time-Stamp Counter (TSC) + running frequency via Model-Specific Register (MSR) and Programmable + Interval Timer (PIT). If the calibration does not work on your board, + select this option and provide a hardcoded TSC running frequency with + CONFIG_TSC_FREQ_IN_MHZ below. + + Normally this option should be turned on in a simulation environment + like qemu. + +config TSC_FREQ_IN_MHZ + int "Time-Stamp Counter (TSC) running frequency in MHz" + depends on TSC_CALIBRATION_BYPASS + default 1000 + help + The running frequency in MHz of Time-Stamp Counter (TSC). + source "arch/x86/cpu/ivybridge/Kconfig" source "arch/x86/cpu/queensbay/Kconfig" |