This commit adds a new coreboot table, CB_TAG_BOOT_MODE, to pass platform boot mode information to the payload. The new table defines flags for low-battery mode and off-mode charging, which are essential for a payload to properly initialize the charger driver. The cb_parse_boot_mode function is added to read this information, and the sysinfo_t structure is updated to store the parsed boot mode data. This ensures that the payload can accurately determine the system's power state at boot and payload operations are also in sync with the boot firmware. The following scenarios were tested and verified: Scenario 1: Low-battery, no charger - coreboot detects the low-battery state and performs an immediate shutdown after displaying the low-battery splash screen. Scenario 2: Low-battery, charger attached - coreboot detects the low-battery state but continues booting because a charger is present. The payload receives the low-battery information (using the same source as coreboot) and correctly initiates the charging process. Scenario 3: Off-mode charging - The system boots directly from an S5 state due to a charger being plugged in. coreboot detects the off-mode state, skips the firmware splash screen, and hands off control to the payload, which then starts charging. Scenario 4: Normal boot - The system boots without any low-battery or off-mode conditions. coreboot and the payload both detect a normal boot (using the same information), bypass charging initialization, and proceed to boot the operating system. TEST=Able to build and boot on google/quenbi device and verify the boot mode flag is correctly passed. Change-Id: Iec25c6fdfcdc5ea7c397d2430ac7b545e1e068f2 Signed-off-by: Subrata Banik <subratabanik@google.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/89015 Reviewed-by: Kapil Porwal <kapilporwal@google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> |
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| .. | ||
| arch | ||
| bin | ||
| configs | ||
| crypto | ||
| curses | ||
| drivers | ||
| gdb | ||
| include | ||
| libc | ||
| libcbfs | ||
| liblz4 | ||
| liblzma | ||
| libpci | ||
| sample | ||
| tests | ||
| vboot | ||
| .gitignore | ||
| Doxyfile | ||
| Kconfig | ||
| LICENSE_GPL | ||
| LICENSES | ||
| Makefile | ||
| Makefile.mk | ||
| Makefile.payload | ||
| README | ||
-------------------------------------------------------------------------------
libpayload README
-------------------------------------------------------------------------------
libpayload is a minimal library to support standalone payloads
that can be booted with firmware like coreboot. It handles the setup
code, and provides common C library symbols such as malloc() and printf().
Note: This is _not_ a standard library for use with an operating system,
rather it's only useful for coreboot payload development!
See https://www.coreboot.org for details on coreboot.
Installation
------------
$ git clone https://review.coreboot.org/coreboot.git
$ cd coreboot/payloads/libpayload
$ make menuconfig
$ make
$ make install (optional, will install into ./install per default)
On x86 systems, libpayload will always be 32-bit even if your host OS runs
in 64-bit, so you might have to install the 32-bit libgcc version.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.
Run 'make distclean' before switching boards. This command will remove
your current .config file, so you need 'make menuconfig' again or
'make defconfig' in order to set up configuration. Default configuration
is based on 'configs/defconfig'. See the configs/ directory for examples
of configuration.
Usage
-----
Here's an example of a very simple payload (hello.c) and how to build it:
#include <libpayload.h>
int main(void)
{
printf("Hello, world!\n");
return 0;
}
Building the payload using the 'lpgcc' compiler wrapper:
$ lpgcc -o hello.elf hello.c
Please see the sample/ directory for details.
Website and Mailing List
------------------------
The main website is https://www.coreboot.org/Libpayload.
For additional information, patches, and discussions, please join the
coreboot mailing list at https://www.coreboot.org/Mailinglist, where most
libpayload developers are subscribed.
Copyright and License
---------------------
See LICENSES.