tree: Move stdlib implementation to builtin directory

Keeping all of the standard library implementation in a single directory
makes it easier to choose between EC's implementation or the
implementation from the toolchain.

BRANCH=none
BUG=b:234181908, b:172020503
TEST=make buildall -j
TEST=Using icetower v0.1, Segger J-Trace, and servo micro:
    ./test/run_device_tests.py -b dartmonkey

    Test "aes": PASSED
    Test "cec": PASSED
    Test "cortexm_fpu": PASSED
    Test "crc": PASSED
    Test "flash_physical": PASSED
    Test "flash_write_protect": PASSED
    Test "fpsensor_hw": PASSED
    Test "fpsensor_spi_ro": PASSED
    Test "fpsensor_spi_rw": PASSED
    Test "fpsensor_uart_ro": PASSED
    Test "fpsensor_uart_rw": PASSED
    Test "mpu_ro": PASSED
    Test "mpu_rw": PASSED
    Test "mutex": PASSED
    Test "pingpong": PASSED
    Test "printf": PASSED
    Test "queue": PASSED
    Test "rollback_region0": PASSED
    Test "rollback_region1": PASSED
    Test "rollback_entropy": PASSED
    Test "rtc": PASSED
    Test "sha256": PASSED
    Test "sha256_unrolled": PASSED
    Test "static_if": PASSED
    Test "system_is_locked_wp_on": PASSED
    Test "system_is_locked_wp_off": PASSED
    Test "timer_dos": PASSED
    Test "utils": PASSED
    Test "utils_str": PASSED
    Test "panic_data_dartmonkey_v2.0.2887": PASSED
    Test "panic_data_nocturne_fp_v2.2.64": PASSED
    Test "panic_data_nami_fp_v2.2.144": PASSED

Signed-off-by: Tom Hughes <tomhughes@chromium.org>
Change-Id: I75f8591e87a9076d47208eb598186a391c77966d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3724488
Reviewed-by: Edward Hill <ecgh@chromium.org>

7 files changed, 20 insertions, 8 deletions

diff --git a/Makefile b/Makefile
index 0602fd4abf..cdf926daa8 100644
--- a/Makefile
+++ b/Makefile
@@ -268,6 +268,7 @@ include $(BASEDIR)/build.mk
 ifneq ($(BASEDIR),$(BDIR))
 include $(BDIR)/build.mk
 endif
+include builtin/build.mk
 include chip/$(CHIP)/build.mk
 include core/$(CORE)/build.mk
 include common/build.mk
@@ -307,6 +308,7 @@ ifneq ($(PBDIR),)
 all-obj-$(1)+=$(call objs_from_dir_p,$(PBDIR),board-private,$(1))
 endif
 all-obj-$(1)+=$(call objs_from_dir_p,common,common,$(1))
+all-obj-$(1)+=$(call objs_from_dir_p,builtin,builtin,$(1))
 all-obj-$(1)+=$(call objs_from_dir_p,driver,driver,$(1))
 all-obj-$(1)+=$(call objs_from_dir_p,power,power,$(1))
 ifdef CTS_MODULE
@@ -353,6 +355,7 @@ dirs=core/$(CORE) chip/$(CHIP) $(BASEDIR) $(BDIR) common fuzz power test \
 dirs+= private private-kandou $(PDIR) $(PBDIR)
 dirs+=$(shell find common -type d)
 dirs+=$(shell find driver -type d)
+dirs+=builtin
 common_dirs=util
 
 ifeq ($(custom-ro_objs-y),)
diff --git a/Makefile.toolchain b/Makefile.toolchain
index 6b82885522..2ce8f2ba5f 100644
--- a/Makefile.toolchain
+++ b/Makefile.toolchain
@@ -89,7 +89,7 @@ CFLAGS_WARN = $(COMMON_WARN) $(C_WARN)
 CXXFLAGS_WARN = $(COMMON_WARN)
 CFLAGS_DEBUG= -g
 CFLAGS_DEBUG+=$(CFLAGS_DEBUG_CHIP)
-CFLAGS_INCLUDE=$(foreach i,$(includes),-I$(i) ) -I.
+CFLAGS_INCLUDE=$(foreach i,$(filter-out builtin, $(includes)),-I$(i) ) -I.
 CFLAGS_TEST=$(if $(TEST_BUILD),-DTEST_BUILD=$(EMPTY) \
                                -DTEST_TASKFILE=$(PROJECT).tasklist,) \
             $(if $(CTS_MODULE), $(CFLAGS_CTS)) \
diff --git a/builtin/build.mk b/builtin/build.mk
new file mode 100644
index 0000000000..c4ec975e6b
--- /dev/null
+++ b/builtin/build.mk
@@ -0,0 +1,6 @@
+# Copyright 2022 The ChromiumOS Authors.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Build for EC's standard library implementation.
+builtin-y=stdlib.o
diff --git a/common/util_stdlib.c b/builtin/stdlib.c
index e42788c4af..e42788c4af 100644
--- a/common/util_stdlib.c
+++ b/builtin/stdlib.c
diff --git a/chip/mchp/build.mk b/chip/mchp/build.mk
index 1e3de24d06..0ffb3a7c4a 100644
--- a/chip/mchp/build.mk
+++ b/chip/mchp/build.mk
@@ -81,9 +81,11 @@ chip-lfw-flat = $(out)/RW/$(chip-lfw)-lfw.flat
 
 # build these specifically for lfw with -lfw suffix
 objs_lfw = $(patsubst %, $(out)/RW/%-lfw.o, \
-		$(addprefix common/, util util_stdlib gpio) \
+		$(addprefix common/, util gpio) \
 		$(addprefix chip/$(CHIP)/, spi qmspi dma gpio clock hwtimer tfdp) \
-		core/$(CORE)/cpu $(chip-lfw))
+		core/$(CORE)/cpu $(chip-lfw) \
+		builtin/stdlib \
+		)
 
 # reuse version.o (and its dependencies) from main board
 objs_lfw += $(out)/RW/common/version.o
diff --git a/common/build.mk b/common/build.mk
index 6473d53291..9f9bad8138 100644
--- a/common/build.mk
+++ b/common/build.mk
@@ -9,7 +9,7 @@
 # Note that this variable includes the trailing "/"
 _common_dir:=$(dir $(lastword $(MAKEFILE_LIST)))
 
-common-y=util.o util_stdlib.o
+common-y=util.o
 common-y+=version.o printf.o queue.o queue_policies.o irq_locking.o
 
 common-$(CONFIG_ACCELGYRO_BMI160)+=math_util.o
diff --git a/zephyr/CMakeLists.txt b/zephyr/CMakeLists.txt
index 444e320dad..b3eaefb2a3 100644
--- a/zephyr/CMakeLists.txt
+++ b/zephyr/CMakeLists.txt
@@ -134,7 +134,11 @@ configure_file(gcov.tmpl.sh ${CMAKE_BINARY_DIR}/gcov.sh)
 # included here, sorted by filename. This is common functionality which is
 # supported by all boards and emulators (including unit tests) using the shim
 # layer.
-zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC "${PLATFORM_EC}/common/base32.c"
+zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC
+                                                # TODO(b/237712836): Remove once
+                                                # Zephyr's libc has strcasecmp.
+                                                "${PLATFORM_EC}/builtin/stdlib.c"
+                                                "${PLATFORM_EC}/common/base32.c"
                                                 "${PLATFORM_EC}/common/console_output.c"
                                                 "${PLATFORM_EC}/common/ec_features.c"
                                                 "${PLATFORM_EC}/common/gpio_commands.c"
@@ -145,9 +149,6 @@ zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC "${PLATFORM_EC}/common/base32.c"
                                                 "${PLATFORM_EC}/common/system.c"
                                                 "${PLATFORM_EC}/common/uart_printf.c"
                                                 "${PLATFORM_EC}/common/util.c"
-                                                # TODO(b/237712836): Remove once
-                                                # Zephyr's libc has strcasecmp.
-                                                "${PLATFORM_EC}/common/util_stdlib.c"
                                                 "${PLATFORM_EC}/common/version.c")
 
 # Now include files that depend on or relate to other CONFIG options, sorted by