| Trusty userspace build system |
| ============================= |
| |
| The userspace build system is built on top of the lk build system, along with |
| the xbin extension for building multiple independent modules. Libraries are |
| built independently into static library archives and their build flags are |
| cached for use by future modules. When a library or app depends on another |
| library, its cached flags are added to the current module flags and re-exported |
| in the case of a library. |
| |
| The top-level entry point for building a userspace app is the |
| `trusty-build-rule` function in user-tasks.mk. This helper function kicks off |
| generation of the necessary build rules using the new module system. See the doc |
| comment on the function's definition for more details on usage. |
| |
| Library rules files must include `make/library.mk` after the appropriate |
| variables have been configured, and similarly, apps must include |
| `make/trusted_app.mk`. These makefiles handle the generation of the appropriate |
| build rules for the app or library. See the comments at the beginning of these |
| makefiles for a full list of the relevant variables that can be set in |
| library/app rules files to control the build. |
| |
| `library.mk` includes `userspace_recurse.mk` to handle isolation of libraries |
| from each other and the main app, along with proper dependency chains and |
| propagation of flags up from dependencies. Users writing rules for libraries |
| should never need to interact with this makefile directly. |
| |
| |
| Example Library Rules |
| --------------------- |
| |
| Note the use of `library.mk` rather than `module.mk`. Apps rules are structured |
| the same, but must include `make/trusted_app.mk` instead of `library.mk`. |
| |
| Libraries and apps must use the MODULE_MODULE_LIBRARY_DEPS variable to add other |
| libraries as dependencies. See `library.mk` for a full list of input variables |
| available for use in library `rules.mk` files. |
| |
| LOCAL_DIR := $(GET_LOCAL_DIR) |
| MODULE := $(LOCAL_DIR) |
| |
| MODULE_SRCS := $(LOCAL_DIR)/source_file.c |
| |
| MODULE_LIBRARY_DEPS := trusty/user/base/lib/tipc |
| |
| include make/library.mk |
| |
| Include Diagram |
| --------------- |
| |
| user-tasks.mk is included by lk make/build.mk as an extra build rule. |
| |
| user-tasks.mk |
| | |
| |--> arch/$(ARCH)/toolchain.mk |
| | |
| |--> For each SDK library $(LIB) in $(TRUSTY_SDK_MODULES): |
| | | MODULE := $(LIB) |
| | | |
| | | /-------------------------------------------------\ |
| | | | | |
| | | v | |
| | make/userspace_recurse.mk | |
| | | | |
| | | Reset all GLOBAL_ and MODULE_ variables to get | |
| | | a clean state. | |
| | | | |
| | |--> $(LIB)/rules.mk | |
| | | | | |
| | | |--> make/library.mk | |
| | | | | | |
| | | | | Cache flags for this module in | |
| | | | | _MODULES_$(MODULE)_$(FLAG) variables. | |
| | | | | | |
| | | | | For each DEPENDENCY_MODULE in | |
| | | | | $(MODULE_LIBRARY_DEPS) | |
| | | | |---------------------------------------/ |
| | | | | |
| | | | | Cache library and ldflags for this module in |
| | | | | _MODULES_$(MODULE)_$(FLAG) variables. |
| | | | | |
| | | | \--> make/module.mk --> make/compile.mk |
| | | | |
| | | | Restore GLOBAL_ and MODULE_ variables to saved values |
| | | | |
| | | | Add dependency's flags to current module's |
| | | | private flags. |
| | | |
| | | |
| | | Restore GLOBAL_ and MODULE_ variables to saved values. |
| | |
| | |
| \--> For each user task $TASK in $(ALL_USER_TASKS): |
| | MODULE := $(TASK) |
| | |
| make/userspace_recurse.mk |
| | |
| | Reset all GLOBAL_ and MODULE_ variables to get |
| | a clean state. |
| | |
| |--> $(TASK)/rules.mk |
| | | |
| | \--> make/trusted_app.mk |
| | | TRUSTY_APP = true |
| | | |
| | | /---------------------------------------------------------------\ |
| | | | | |
| | | v | |
| | |--> make/library.mk | |
| | | | | |
| | | | Cache flags for this module in _MODULES_$(MODULE)_$(FLAG) | |
| | | | variables. | |
| | | | | |
| | | | For each DEPENDENCY_MODULE in | |
| | | | $(MODULE_LIBRARY_DEPS): | |
| | | |--> make/userspace_recurse.mk | |
| | | | | | |
| | | | | Reset all GLOBAL_ and MODULE_ variables to get | |
| | | | | a clean state. | |
| | | | | | |
| | | | | TRUSTY_APP = false | |
| | | | | | |
| | | | |--> $(DEP)/rules.mk | |
| | | | | | | |
| | | | | \______________________________________________/ |
| | | | | |
| | | | | |
| | | | | Restore GLOBAL_ and MODULE_ variables to saved values |
| | | | | |
| | | | | Add dependency's flags to current module's |
| | | | | private flags. |
| | | | |
| | | | Cache library and ldflags for this module in |
| | | | _MODULES_$(MODULE)_$(FLAG) variables. |
| | | | |
| | | \--> make/module.mk --> make/compile.mk |
| | | |
| | | |
| | | Build app ELF binary from objects and all dependency libraries |
| | | (formerly done by xbin.mk). |
| | |
| | |
| | Restore GLOBAL_ and MODULE_ variables to saved values. |
