Build SD card image
You can build all-in-one SD card image by single make command from this commit.
make KEYSTONE_PLATFORM=unmatched -j $(nproc)SD card image is to be located in build-unmatched64/buildroot.build/images/sdcard.img
Included components
Some patches included in freedom-u-sdk are also applied.
- U-Boot SPL
- applied secureboot patch for Keystone
- Keystone SM (OpenSBI)
- U-Boot
- load address is modified due to PMP conflict issue
- Buildroot
- Linux
- Keystone Driver
Known Issues
- building linux perf sometimes fails
- re-running make , build will succeed
Deal with buildroot build system
In Keystone’s build system, buildroot target can be passed directly by BUILDROOT_TARGET. For example,
make BUILDROOT_TARGET=linux-buildTarget name format is <package>-<command>. <package> is package name such as linux, u-boot, opensbi and keystone-sm. <command> is subcommand for package such as build, configure, patch, clean and rebuild.
Build single component
Keystone SM
You can build following command:
make KEYSTONE_PLATFORM=unmatched BUILDROOT_TARGET=opensbi-buildArtifacts are located in build-unmatched64/buildroot.build/build/opensbi-<version>/build/platform/generic/firmware
PMP issue
Security Monitor set no permission to range 0x80000000 - 0x801fffff. But U-Boot initially set stack pointer its load address, 0x80200000, and stack stretches to lower region. So U-Boot try to touch protected region, and access violation occurs.
Changing U-Boot’s load address to upper region solve this issue. U-Boot built in keystone build system is loaded to 0x80210000.
U-Boot load address can be changed by adding/modifying config as following:
CONFIG_TEXT_BASE=0x80210000
CONFIG_SYS_LOAD_ADDR=0x80210000