External packages

.gitignore

@@ -56,4 +56,4 @@ gdbinit
 src/components/lib/libc/musl-1.2.0/include/asm/
 src/components/lib/libc/musl-1.2.0/include/asm-generic/
 src/components/lib/libc/musl-1.2.0/include/linux/
-src/components/lib/libc/musl-1.2.0/include/sys/queue.h
+src/components/lib/libc/musl-1.2.0/include/sys/queue.h

composition_scripts/burn.toml

@@ -0,0 +1,15 @@
+[system]
+description = "Simple system running only a CPU-burn component."
+
+[[components]]
+name = "booter"
+img  = "no_interface.llbooter"
+implements = [{interface = "init"}, {interface = "addr"}]
+deps = [{srv = "kernel", interface = "init", variant = "kernel"}]
+constructor = "kernel"
+
+[[components]]
+name = "burn"
+img  = "no_interface.burn"
+deps = [{srv = "booter", interface = "init"}, {srv = "booter", interface = "addr"}]
+constructor = "booter"

composition_scripts/external_hello_world.toml

@@ -0,0 +1,9 @@
+[system]
+description = "Test for the hello world external component"
+
+[[components]]
+name = "hw1"
+img  = ""
+repo = "github:gparmer/hello_world"
+deps = [{srv = "kernel", interface = "init", variant = "kernel"}]
+constructor = "kernel"

src/Makefile

@@ -1,6 +1,7 @@
 #MAKEFLAGS=--no-print-directory --section-alignment 0x1000 -I$(PWD)
 # Note: can't use $(PWD) here if make -Ced from elsewhere.
 MAKEOPTIONS=--no-print-directory -I$(shell pwd)
+export MAKEOPTIONS
 PLAT_FILE=.PLATFORM_ID
 
 .PHONY: default all composer component comps platclean plat cpplat clean distclean init update config
@@ -20,6 +21,10 @@ composer:
 component:
 	$(MAKE) $(MAKEOPTIONS) -C components component
 
+# Download an external repository
+repo_external:
+	$(MAKE) $(MAKEOPTIONS) -C components repo_external
+
 comps:
 	$(info )
 	$(info ***********************************************)

src/Makefile.src

@@ -11,6 +11,7 @@ KINC=$(TOP_DIR)/kernel/include/
 SHAREDINC=$(TOP_DIR)/kernel/include/shared/
 CHALSHAREDINC=$(TOP_DIR)/kernel/include/chal/shared/
 CDIR=$(TOP_DIR)/components/
+REPO_DIR=$(CDIR)/repos
 
 # tools
 MAKE=make
@@ -25,3 +26,8 @@ CP=cp
 RM=rm
 PLAT_FILE=$(TOP_DIR)/.PLATFORM_ID
 PLATFORM=$(shell cat $(PLAT_FILE))
+
+# disable the terminal prompts, and fail out instead; typically fails
+# if ssh isn't set up (known hosts), or if the specified repo doesn't
+# exist.
+GITCLONE=GIT_TERMINAL_PROMPT=0 git clone

src/components/Makefile

@@ -1,4 +1,6 @@
-MAKEOPTIONS=-I$(shell pwd)
+include Makefile.src
+MAKEOPTIONS+= -I$(shell pwd)
+export MAKEOPTIONS
 
 # Order of which subdirectories are built first matters here.
 # Interface files rely on library files, and component implementations
@@ -24,3 +26,12 @@ init:
 
 component:
 	$(MAKE) $(MAKEOPTIONS) -C implementation component
+
+# Download a remote repository (e.g. from github). We're setting up a
+# specific rule for the repo's path so that it won't redundantly clone
+# the repo. Once it has been cloned, never clone it again.
+REPO_ABSPATH = $(REPO_DIR)/$(REPO_PATH)
+$(REPO_ABSPATH):
+	$(GITCLONE) $(REPO_URL) $@
+
+repo_external: $(REPO_ABSPATH)

src/components/implementation/Makefile

@@ -1,7 +1,8 @@
 include Makefile.src Makefile.comp
 
 SUBDIRS=$(filter-out skel/, $(wildcard */))
-MAKEOPTIONS=-I$(shell pwd)
+MAKEOPTIONS+= -I$(shell pwd)
+export MAKEOPTIONS
 
 .PHONY: all
 all:
@@ -23,5 +24,12 @@ clean:
 init:
 distclean:
 
+# NOTE: we're skipping the compilation of the libraries in the
+# interfaces directories (the immediate subdirectories here) on
+# composer-directed compilation. Soon, we'll remove the need for
+# interface directories, and will move all of their shared code into
+# the `lib/` code.
+#
+# NOTE: COMP_PATH is relative to the `src/component` (CDIR) directory.
 component:
-	$(MAKE) $(MAKEOPTIONS) -C $(COMP_INTERFACE) component
+	$(MAKE) $(MAKEOPTIONS) -C $(CDIR)/$(COMP_PATH) component

src/components/implementation/Makefile.subdir

@@ -21,7 +21,7 @@ print:
 .PHONY: subdirs
 subdirs:
 	@for dir in $(SUBDIRS) ; do \
-		$(MAKE) -C $$dir ;  \
+		$(MAKE) $(MAKEOPTIONS) -C $$dir ;  \
 	done
 
 $(CLIB):$(OBJS)
@@ -75,6 +75,6 @@ clean:
 
 .PHONY: component
 component:
-	$(MAKE) -C $(COMP_NAME) component
+	$(MAKE) $(MAKEOPTIONS) -C $(COMP_NAME) component
 
 -include $(SOURCE_DEPENDENCIES)

src/components/implementation/Makefile.subsubdir

@@ -40,7 +40,7 @@ ifeq ($(PLATFORM), i386)
 LINKFLAG=-Xlinker -melf_i386
 COMP_LD_SCRIPT=$(IMPLDIR)/comp_i386.ld
 else ifeq ($(PLATFORM), x86_64)
-LINKFLAG=-Xlinker -melf_x86_64 
+LINKFLAG=-Xlinker -melf_x86_64
 COMP_LD_SCRIPT=$(IMPLDIR)/comp_x86_64.ld
 else ifeq ($(PLATFORM), armv7a)
 LINKFLAG=-Xlinker -marmelf
@@ -82,13 +82,14 @@ COMP_DEP_OBJS=$(foreach D,$(COMP_IFDEPS_CLEAN),$(INTERDIR)/$(D)/cosrt_c_stub.o)
 # NOTE: we're currently ignoring the *variants* library requirements,
 # which will break if an interface's code requires a library
 
+
 comp_header:
-	$(info | Composing $(COMP_INTERFACE).$(COMP_NAME) for variable $(COMP_VARNAME) by linking with:)
+	$(info | Composing component in src/components/$(COMP_PATH) for variable $(COMP_VARNAME) by linking with:)
 	$(info |     Exported interfaces: $(COMP_INTERFACES_CLEAN))
 	$(info |     Interface dependencies: $(COMP_IFDEPS_CLEAN))
 	$(info |     Libraries: $(DEPENDENCY_LIBS) $(DEPENDENCY_LIBOBJS))
 
-.PHONY: component
+.PHONY: component comp_header
 component: clean comp_header $(COMPOBJ)
 	$(if $(COMP_INITARGS_FILE), $(CC) $(INCLUDE) $(CFLAGS) -c -o $(COMP_INITARGS_FILE:%.c=%.o) $(COMP_INITARGS_FILE))
 	$(if $(COMP_TAR_FILE), cp $(COMP_TAR_FILE) $(TAR_SYMBOL_NAME))
@@ -97,6 +98,8 @@ component: clean comp_header $(COMPOBJ)
 	$(MUSLCC) $(COMPNAME).linked_libs_ifs.o $(MUSLCFLAGS) $(LINKFLAG) -o $(COMPNAME).linked_musl.o
 	$(LD) $(LDFLAGS) -Ttext=$(COMP_BASEADDR) -T $(COMP_LD_SCRIPT) -o $(COMP_OUTPUT) $(COMPNAME).linked_musl.o
 
+component_external:
+
 %.o:%.c
 	$(info |     [CC]   $<: Compiling)
 	@$(CC) $(INCLUDE) $(CFLAGS) -o $@ -c $<
@@ -112,7 +115,7 @@ component: clean comp_header $(COMPOBJ)
 # see the make manual: create the .d dependencies from include
 # statements.
 # redirect error output to /dev/null so that it will not display
-# errors when cleaning, this does not affect gcc's error output when 
+# errors when cleaning, this does not affect gcc's error output when
 # building the system because that is in a different target path
 %.d:%.c
 	@set +e; rm -f $@; \

src/components/implementation/no_interface/burn/Makefile

@@ -0,0 +1,18 @@
+# Required variables used to drive the compilation process. It is OK
+# for many of these to be empty.
+#
+# The set of interfaces that this component exports for use by other
+# components. This is a list of the interface names.
+INTERFACE_EXPORTS =
+# The interfaces this component is dependent on for compilation (this
+# is a list of directory names in interface/)
+INTERFACE_DEPENDENCIES =
+# The library dependencies this component is reliant on for
+# compilation/linking (this is a list of directory names in lib/)
+LIBRARY_DEPENDENCIES = component
+# Note: Both the interface and library dependencies should be
+# *minimal*. That is to say that removing a dependency should cause
+# the build to fail. The build system does not validate this
+# minimality; that's on you!
+
+include Makefile.subsubdir

src/components/implementation/no_interface/burn/burn.c

@@ -0,0 +1,11 @@
+#include <llprint.h>
+
+void
+cos_init(void)
+{
+	/* Burn all of the cycles! CPUs are glorified space heaters, right? */
+	printc("CPU cycle burn: component %ld, thread id %ld, core %d.\n",
+	       cos_compid(), cos_thdid(), cos_coreid());
+
+	while (1) ;
+}

src/components/implementation/no_interface/burn/doc.md

@@ -0,0 +1,12 @@
+## CPU Burn Component
+
+A simple component that burns CPU cycles, nothing else.
+Can be used in test scenarios as background, CPU-intensive computations.
+
+### Description
+
+Simple infinite loop, nothing more.
+
+### Usage and Assumptions
+
+Only depends on the `init` interface, so it can be used anywhere from on top of the constructor, all the way to as a component under the scheduler.

src/components/repos/.gitignore

@@ -0,0 +1,3 @@
+*
+!.gitignore
+!README.md

src/components/repos/README.md

@@ -0,0 +1,24 @@
+# External Repositories
+
+Composite current enables components to be defined externally from the main repo, thus providing increased autonomy in development.
+Each repository in this directory is pulled from github, and can contain a set of components and composition scripts.
+These repositories can be thought of as part of the Composite ecosystem, but not as part of the "standard library" of necessary functionalities.
+
+A number of awkward realities with the current system:
+
+- Composite does *not* maintain the repos downloaded here in any way.
+    If the upstream repo is changed, you must manually do a `git pull` in the repo (or remove it so it is re-cloned).
+	Comparably, if you update the external repo, you should manually commit/push, etc...
+- The Composite repo ignores all repos in here.
+    Never add them.
+	The proper course of action would be to do a PR to the main Composite repo adding your component instead.
+
+## TODO: Libraries and Interfaces
+
+It should be possible to also define libraries and interfaces in external repositories.
+This is more complicated as the dependencies for these are
+
+1. not properly maintained by the composer (libraries aren't properly rebuilt when one of their dependencies changed), and
+2. these dependencies are tracked by the build system, so updating them to enable dependencies are repositories requires most structural updates to the build system.
+
+There are no hard blockers to doing this; we just need more time and will!