Pre-operating system display brightness management based on battery condition
Particular embodiments described herein provide for an electronic device that includes a battery, a display, an embedded controller to determine a battery condition and set an indicator when then battery condition is at a low power state, and a basic input/output system (BIOS), where, before an operating system stage of a boot process, the BIOS sets a brightness of the display at a native brightness if the indicator is not set and sets the brightness of the display at a low power brightness to reduce the brightness of the display if the indicator is set. In an example, the embedded controller sets the indicator before the central processing unit is reset during the boot process.
1 . An electronic device comprising:
a battery;
a display;
an embedded controller to determine a battery condition of the battery and set an indicator before memory initialization, during a pre-CPU reset stage of a current boot process when the battery condition is in a low power state, wherein the embedded controller sets the indicator in a memory region accessible to basic input/output system (BIOS); and
the BIOS, wherein, before an operating system stage of the boot process, the BIOS reads the indicator from the memory region and sets a brightness of the display at a native brightness if the indicator is not set and sets the brightness of the display at a low power brightness to reduce the brightness of the display to a reduced nonzero brightness level if the indicator is set.
2 . The electronic device of claim 1 , wherein the electronic device is connected to an external power source using a USB-C cable.
3 . The electronic device of claim 2 , wherein the USB-C cable supplies fifteen watts of power or less during a boot up process.
4 . The electronic device of claim 1 , wherein the display is a liquid crystal display and the brightness is reduced by reducing a backlight.
5 . The electronic device of claim 1 , wherein the display is an OLED display and the brightness is reduced by initializing the display with a negative contrast polarity.
6 . The electronic device of claim 1 , wherein the indicator is also set if the electronic device is updating firmware or an operating system.
7 . The electronic device of claim 1 , wherein the battery condition is at the low power state when a capacity level of the battery is four percent or less.
8 . A method comprising:
determining that an electronic device with a display is powered on using a battery;
starting a boot process for the electronic device;
determining a battery condition of the battery;
setting an indicator in a memory region accessible to basic input/output system (BIOS) before memory initialization, during a pre-CPU reset stage during the current boot process if the battery condition is at a low power state;
reading, by the BIOS, the indicator from the memory region; and
setting a brightness of the display to a native brightness if the indicator is not set; and
setting the brightness of the display to a low power brightness to reduce the brightness of the display to a reduced nonzero brightness level if the indicator is set.
9 . The method of claim 8 , wherein an embedded controller determines the battery condition before a central processing unit of the electronic device is reset.
10 . The method of claim 8 , wherein a basic input/output system (BIOS) causes the brightness of the display to be set to a low power brightness if the indicator is set.
11 . The method of claim 8 , wherein the brightness of the display is set before an operating system stage of the boot process.
12 . The method of claim 8 , wherein the display is liquid crystal display and the brightness is reduced by reducing a backlight.
13 . The method of claim 8 , wherein the display is an OLED display and the brightness is reduced by initializing the display with a negative contrast polarity.
14 . A system for enabling pre-operating system display management, the system comprising:
a battery;
a display;
one or more processors; and
one or more instructions that, when executed by the one or more processors, cause the one or more processors to:
determine a battery condition and set an indicator in a memory region accessible to a basic input/output system (BIOS) when the battery condition is at a low power state before memory initialization, during a pre-CPU reset stage during a current boot process; and
read, by the BIOS, the indicator from the memory region and set a brightness of display at a native brightness if the indicator is not set and set the brightness of the display at a low power brightness to reduce the brightness of the display to a reduced nonzero brightness level if the indicator is set.
15 . The system of claim 14 , further comprising:
an embedded controller to determine the battery condition before a central processing unit is reset during the boot process.
16 . The system of claim 14 , wherein the display is a liquid crystal display and the brightness is reduced by reducing a backlight.
17 . The system of claim 14 , wherein the display is an OLED display and the brightness is reduced by initializing the display with a negative contrast polarity.
18 . The system of claim 17 , wherein the system is connected to an external power source using a USB-C cable and the USB-C cable supplies fifteen watts of power or less during the boot process.