build: use thin archives rather than incremental linking

This changes to build system to use thin archives rather than
incremental linking for built-in.o, similar to recent change to Linux.
built-in.o is renamed to built-in.a, and is created as a thin archive
with no index, for speed and size. All built-in.a are aggregated into
a skiboot.tmp.a which is a thin archive built with an index, making it
suitable or linking. This is input into the final link.

The advantags of build size and linker code placement flexibility are
not as great with skiboot as a bigger project like Linux, but it's a
conceptually better way to build, and is more compatible with link
time optimisation in toolchains which might be interesting for skiboot
particularly for size reductions.

Size of build tree before this patch is 34.4MB, afterwards 23.1MB.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

30 files changed, 40 insertions, 35 deletions

diff --git a/Makefile.main b/Makefile.main
index 46ad3b0..9683638 100644
--- a/Makefile.main
+++ b/Makefile.main
@@ -126,7 +126,7 @@ LDFLAGS += -Wl,-pie
 LDFLAGS += -Wl,-Ttext-segment,$(LD_TEXT) -Wl,-N -Wl,--build-id=none
 LDFLAGS += -Wl,--no-multi-toc
 LDFLAGS += -mcpu=power7 -mbig-endian -Wl,--oformat,elf64-powerpc
-
+LDFLAGS_FINAL = $(LDFLAGS) -Wl,--whole-archive
 LDRFLAGS=-melf64ppc
 # Debug stuff
 #LDFLAGS += -Wl,-v -Wl,-Map,foomap 
@@ -213,8 +213,8 @@ OBJS += $(LIBC) $(CCAN) $(DEVSRC_OBJ) $(LIBPORE)
 OBJS_NO_VER = $(OBJS)
 ALL_OBJS = $(OBJS) version.o
 
-ALL_OBJS_1 = $(ALL_OBJS) asm/dummy_map.o
-ALL_OBJS_2 = $(ALL_OBJS) asm/real_map.o
+ALL_OBJS_1 = $(TARGET).tmp.a asm/dummy_map.o
+ALL_OBJS_2 = $(TARGET).tmp.a asm/real_map.o
 
 $(TARGET).lid.xz: $(TARGET).lid
 	$(call Q,XZ, cat $^ | xz -9 -C crc32 > $@, $@)
@@ -228,13 +228,17 @@ $(TARGET).lid.stb: $(TARGET).lid libstb/create-container
 $(TARGET).lid.xz.stb: $(TARGET).lid.xz libstb/create-container
 	$(call Q,STB-DEVELOPMENT-SIGNED-CONTAINER,$(SRC)/libstb/sign-with-local-keys.sh $< $@ $(SRC)/libstb/keys/ PAYLOAD,$@)
 
+$(TARGET).tmp.a: $(ALL_OBJS)
+	@rm -f $(TARGET).tmp.a
+	$(call Q,AR, $(AR) rcsTPD $@ $(ALL_OBJS), $@)
+
 $(TARGET).tmp.elf: $(ALL_OBJS_1) $(TARGET).lds $(KERNEL)
-	$(call Q,LD, $(CC) $(LDFLAGS) -T $(TARGET).lds $(ALL_OBJS_1) -o $@, $@)
+	$(call Q,LD, $(CC) $(LDFLAGS_FINAL) -o $@ -T $(TARGET).lds $(ALL_OBJS_1), $@)
 
 asm/real_map.o : $(TARGET).tmp.map
 
 $(TARGET).elf: $(ALL_OBJS_2) $(TARGET).lds $(KERNEL)
-	$(call Q,LD, $(CC) $(LDFLAGS) -T $(TARGET).lds $(ALL_OBJS_2) -o $@, $@)
+	$(call Q,LD, $(CC) $(LDFLAGS_FINAL) -o $@ -T $(TARGET).lds $(ALL_OBJS_2), $@)
 
 $(SUBDIRS):
 	$(call Q,MKDIR,mkdir -p $@, $@)
diff --git a/Makefile.rules b/Makefile.rules
index 80121c3..e5f6dfc 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -67,8 +67,9 @@ endif
 %.i : %.c
 	$(call Q,CC, $(CC) $(call cook_cflags,$@) -E -c $< -o $@, $@)
 
-%built-in.o :
-	$(call Q,LD, $(LD) $(LDRFLAGS) -r $^ -o $@, $@)
+%built-in.a :
+	@rm -f $@
+	$(call Q,AR, $(AR) rcSTPD $@ $^, $@)
 
 %.lds : %.lds.S
 	$(call Q,CC, $(CC) $(CPPFLAGS) -P -E $< -o $@, $@)
diff --git a/asm/Makefile.inc b/asm/Makefile.inc
index 2828caf..343abc2 100644
--- a/asm/Makefile.inc
+++ b/asm/Makefile.inc
@@ -2,7 +2,7 @@
 
 SUBDIRS += asm 
 ASM_OBJS = head.o misc.o kernel-wrapper.o cvc_entry.o
-ASM=asm/built-in.o
+ASM=asm/built-in.a
 
 # Add extra dependency to the kernel wrapper
 kernel_wrapper.o : $(KERNEL)
diff --git a/ccan/Makefile.inc b/ccan/Makefile.inc
index 1a89b2e..36e7577 100644
--- a/ccan/Makefile.inc
+++ b/ccan/Makefile.inc
@@ -2,7 +2,7 @@
 
 SUBDIRS += ccan ccan/list ccan/str
 CCAN_OBJS = list/list.o str/str.o
-CCAN=ccan/built-in.o
+CCAN=ccan/built-in.a
 
 $(CCAN): $(CCAN_OBJS:%=ccan/%)
 
diff --git a/core/Makefile.inc b/core/Makefile.inc
index 5c12056..d363505 100644
--- a/core/Makefile.inc
+++ b/core/Makefile.inc
@@ -15,7 +15,7 @@ ifeq ($(SKIBOOT_GCOV),1)
 CORE_OBJS += gcov-profiling.o
 endif
 
-CORE=core/built-in.o
+CORE=core/built-in.a
 
 CFLAGS_SKIP_core/relocate.o = -pg -fstack-protector-all
 CFLAGS_SKIP_core/relocate.o += -fstack-protector -fstack-protector-strong
diff --git a/hdata/Makefile.inc b/hdata/Makefile.inc
index c17b04f..6f47314 100644
--- a/hdata/Makefile.inc
+++ b/hdata/Makefile.inc
@@ -3,6 +3,6 @@
 SUBDIRS += hdata
 HDATA_OBJS = spira.o paca.o pcia.o hdif.o memory.o fsp.o iohub.o vpd.o slca.o
 HDATA_OBJS += cpu-common.o vpd-common.o hostservices.o i2c.o tpmrel.o
-DEVSRC_OBJ = hdata/built-in.o
+DEVSRC_OBJ = hdata/built-in.a
 
 $(DEVSRC_OBJ): $(HDATA_OBJS:%=hdata/%)
diff --git a/hw/Makefile.inc b/hw/Makefile.inc
index 04cacd1..2dc3cc0 100644
--- a/hw/Makefile.inc
+++ b/hw/Makefile.inc
@@ -8,7 +8,7 @@ HW_OBJS += phb3.o sfc-ctrl.o fake-rtc.o bt.o p8-i2c.o prd.o
 HW_OBJS += dts.o lpc-rtc.o npu.o npu-hw-procedures.o xive.o phb4.o
 HW_OBJS += fake-nvram.o lpc-mbox.o npu2.o npu2-hw-procedures.o
 HW_OBJS += phys-map.o sbe-p9.o capp.o occ-sensor.o vas.o
-HW=hw/built-in.o
+HW=hw/built-in.a
 
 # FIXME hack this for now
 CFLAGS_hw/phb4.o = -Wno-unused-value -Wno-unused-parameter
diff --git a/hw/ast-bmc/Makefile.inc b/hw/ast-bmc/Makefile.inc
index a97c0db..29e7a35 100644
--- a/hw/ast-bmc/Makefile.inc
+++ b/hw/ast-bmc/Makefile.inc
@@ -1,5 +1,5 @@
 SUBDIRS += hw/ast-bmc
 
 AST_BMC_OBJS  = ast-io.o ast-sf-ctrl.o
-AST_BMC = hw/ast-bmc/built-in.o
+AST_BMC = hw/ast-bmc/built-in.a
 $(AST_BMC): $(AST_BMC_OBJS:%=hw/ast-bmc/%)
diff --git a/hw/ec/Makefile.inc b/hw/ec/Makefile.inc
index 09c9c84..f944d4d 100644
--- a/hw/ec/Makefile.inc
+++ b/hw/ec/Makefile.inc
@@ -3,6 +3,6 @@
 
 SUBDIRS += hw/ec
 EC_OBJS = gpio.o
-EC=hw/ec/built-in.o
+EC=hw/ec/built-in.a
 
 $(EC): $(EC_OBJS:%=hw/ec/%)
diff --git a/hw/fsp/Makefile.inc b/hw/fsp/Makefile.inc
index 7169095..7a477db 100644
--- a/hw/fsp/Makefile.inc
+++ b/hw/fsp/Makefile.inc
@@ -6,5 +6,5 @@ FSP_OBJS += fsp-diag.o fsp-leds.o fsp-mem-err.o fsp-op-panel.o
 FSP_OBJS += fsp-elog-read.o fsp-elog-write.o fsp-epow.o fsp-dpo.o
 FSP_OBJS += fsp-dump.o fsp-mdst-table.o fsp-chiptod.o fsp-ipmi.o
 FSP_OBJS += fsp-attn.o
-FSP = hw/fsp/built-in.o
+FSP = hw/fsp/built-in.a
 $(FSP): $(FSP_OBJS:%=hw/fsp/%)
diff --git a/hw/ipmi/Makefile.inc b/hw/ipmi/Makefile.inc
index a54602c..34d6bd3 100644
--- a/hw/ipmi/Makefile.inc
+++ b/hw/ipmi/Makefile.inc
@@ -3,5 +3,5 @@ SUBDIRS += hw/ipmi
 IPMI_OBJS  = ipmi-rtc.o ipmi-power.o ipmi-fru.o ipmi-sel.o
 IPMI_OBJS += ipmi-watchdog.o ipmi-sensor.o ipmi-attn.o
 
-IPMI = hw/ipmi/built-in.o
+IPMI = hw/ipmi/built-in.a
 $(IPMI): $(IPMI_OBJS:%=hw/ipmi/%)
diff --git a/libc/Makefile.inc b/libc/Makefile.inc
index 66ce4ab..13f8034 100644
--- a/libc/Makefile.inc
+++ b/libc/Makefile.inc
@@ -1,7 +1,7 @@
 LIBCDIR = libc
 
 SUBDIRS += $(LIBCDIR)
-LIBC = $(LIBCDIR)/built-in.o $(LIBCDIR)/time.o
+LIBC = $(LIBCDIR)/built-in.a $(LIBCDIR)/time.o
 
 include $(SRC)/$(LIBCDIR)/string/Makefile.inc
 include $(SRC)/$(LIBCDIR)/ctype/Makefile.inc
diff --git a/libc/ctype/Makefile.inc b/libc/ctype/Makefile.inc
index da78c98..c183a54 100644
--- a/libc/ctype/Makefile.inc
+++ b/libc/ctype/Makefile.inc
@@ -14,6 +14,6 @@ SUBDIRS += $(LIBCDIR)/ctype
 
 CTYPE_OBJS = isdigit.o isprint.o isspace.o isxdigit.o tolower.o toupper.o
 
-CTYPE = $(LIBCDIR)/ctype/built-in.o
+CTYPE = $(LIBCDIR)/ctype/built-in.a
 $(CTYPE): $(CTYPE_OBJS:%=$(LIBCDIR)/ctype/%)
 
diff --git a/libc/stdio/Makefile.inc b/libc/stdio/Makefile.inc
index d2aee0f..a5436d7 100644
--- a/libc/stdio/Makefile.inc
+++ b/libc/stdio/Makefile.inc
@@ -17,5 +17,5 @@ STDIO_OBJS = vfprintf.o vsnprintf.o fprintf.o \
 	     setvbuf.o fputc.o puts.o fputs.o putchar.o \
 	     stdchnls.o fileno.o snprintf.o
 
-STDIO = $(LIBCDIR)/stdio/built-in.o
+STDIO = $(LIBCDIR)/stdio/built-in.a
 $(STDIO): $(STDIO_OBJS:%=$(LIBCDIR)/stdio/%)
diff --git a/libc/stdlib/Makefile.inc b/libc/stdlib/Makefile.inc
index 22417df..8a78d17 100644
--- a/libc/stdlib/Makefile.inc
+++ b/libc/stdlib/Makefile.inc
@@ -15,6 +15,6 @@ SUBDIRS += $(LIBCDIR)/stdlib
 STDLIB_OBJS = error.o atoi.o atol.o strtol.o strtoul.o \
 	      rand.o labs.o
 
-STDLIB = $(LIBCDIR)/stdlib/built-in.o
+STDLIB = $(LIBCDIR)/stdlib/built-in.a
 $(STDLIB): $(STDLIB_OBJS:%=$(LIBCDIR)/stdlib/%)
 
diff --git a/libc/string/Makefile.inc b/libc/string/Makefile.inc
index fb2f037..122f5da 100644
--- a/libc/string/Makefile.inc
+++ b/libc/string/Makefile.inc
@@ -16,6 +16,6 @@ STRING_OBJS = strcat.o strchr.o strcmp.o strcpy.o strlen.o \
 	      strncmp.o strncpy.o strstr.o memset.o memcpy.o memcpy_from_ci.o \
 	      memmove.o memchr.o memcmp.o strcasecmp.o strncasecmp.o \
 	      strtok.o strdup.o
-STRING = $(LIBCDIR)/string/built-in.o
+STRING = $(LIBCDIR)/string/built-in.a
 $(STRING): $(STRING_OBJS:%=$(LIBCDIR)/string/%)
 
diff --git a/libfdt/Makefile.inc b/libfdt/Makefile.inc
index e477d7c..63c9d38 100644
--- a/libfdt/Makefile.inc
+++ b/libfdt/Makefile.inc
@@ -12,7 +12,7 @@ LIBFDT_OBJS = $(LIBFDT_SRCS:%.c=%.o)
 CFLAGS_SKIP_libfdt/fdt_sw.o = -Wstack-usage=4096
 
 SUBDIRS += libfdt
-LIBFDT = libfdt/built-in.o
+LIBFDT = libfdt/built-in.a
 
 $(LIBFDT): $(LIBFDT_OBJS:%=libfdt/%)
 
diff --git a/libflash/Makefile.inc b/libflash/Makefile.inc
index ea64eb4..2474abf 100644
--- a/libflash/Makefile.inc
+++ b/libflash/Makefile.inc
@@ -2,6 +2,6 @@ LIBFLASH_SRCS = libflash.c libffs.c ecc.c blocklevel.c mbox-flash.c
 LIBFLASH_OBJS = $(LIBFLASH_SRCS:%.c=%.o)
 
 SUBDIRS += libflash
-LIBFLASH = libflash/built-in.o
+LIBFLASH = libflash/built-in.a
 
 $(LIBFLASH): $(LIBFLASH_OBJS:%=libflash/%)
diff --git a/libpore/Makefile.inc b/libpore/Makefile.inc
index cc89127..1060a04 100644
--- a/libpore/Makefile.inc
+++ b/libpore/Makefile.inc
@@ -3,7 +3,7 @@ LIBPORE_SRCS += p8_pore_table_static_data.c sbe_xip_image.c pore_inline_assemble
 LIBPORE_OBJS_1 = $(LIBPORE_SRCS:%.c=%.o)
 LIBPORE_OBJS = $(LIBPORE_OBJS_1:%.C=%.o)
 SUBDIRS += libpore
-LIBPORE = libpore/built-in.o
+LIBPORE = libpore/built-in.a
 
 CFLAGS_SKIP_libpore/pore_inline_assembler.o=-Wsuggest-attribute=const
 
diff --git a/libstb/Makefile.inc b/libstb/Makefile.inc
index 3ea530a..6d54c5c 100644
--- a/libstb/Makefile.inc
+++ b/libstb/Makefile.inc
@@ -6,7 +6,7 @@ SUBDIRS += $(LIBSTB_DIR)
 
 LIBSTB_SRCS = container.c tpm_chip.c cvc.c secureboot.c trustedboot.c
 LIBSTB_OBJS = $(LIBSTB_SRCS:%.c=%.o)
-LIBSTB = $(LIBSTB_DIR)/built-in.o
+LIBSTB = $(LIBSTB_DIR)/built-in.a
 
 include $(SRC)/$(LIBSTB_DIR)/mbedtls/Makefile.inc
 include $(SRC)/$(LIBSTB_DIR)/drivers/Makefile.inc
diff --git a/libstb/drivers/Makefile.inc b/libstb/drivers/Makefile.inc
index 3b8ed0f..80356eb 100644
--- a/libstb/drivers/Makefile.inc
+++ b/libstb/drivers/Makefile.inc
@@ -6,6 +6,6 @@ SUBDIRS += $(DRIVERS_DIR)
 
 DRIVERS_SRCS = tpm_i2c_interface.c tpm_i2c_nuvoton.c
 DRIVERS_OBJS = $(DRIVERS_SRCS:%.c=%.o)
-DRIVERS = $(DRIVERS_DIR)/built-in.o
+DRIVERS = $(DRIVERS_DIR)/built-in.a
 
 $(DRIVERS): $(DRIVERS_OBJS:%=$(DRIVERS_DIR)/%)
diff --git a/libstb/mbedtls/Makefile.inc b/libstb/mbedtls/Makefile.inc
index 07aa26a..deacd26 100644
--- a/libstb/mbedtls/Makefile.inc
+++ b/libstb/mbedtls/Makefile.inc
@@ -6,6 +6,6 @@ SUBDIRS += $(MBEDTLS_DIR)
 
 MBEDTLS_SRCS = sha512.c
 MBEDTLS_OBJS = $(MBEDTLS_SRCS:%.c=%.o)
-MBEDTLS = $(MBEDTLS_DIR)/built-in.o
+MBEDTLS = $(MBEDTLS_DIR)/built-in.a
 
 $(MBEDTLS): $(MBEDTLS_OBJS:%=$(MBEDTLS_DIR)/%)
diff --git a/libstb/tss/Makefile.inc b/libstb/tss/Makefile.inc
index 2b5c3b9..ed5154d 100644
--- a/libstb/tss/Makefile.inc
+++ b/libstb/tss/Makefile.inc
@@ -7,7 +7,7 @@ SUBDIRS += $(TSS_DIR)
 TSS_SRCS = trustedbootCmds.C trustedTypes.C trustedbootUtils.C \
 	   tpmLogMgr.C
 TSS_OBJS = $(TSS_SRCS:%.C=%.o)
-TSS = $(TSS_DIR)/built-in.o
+TSS = $(TSS_DIR)/built-in.a
 
 $(TSS): $(TSS_OBJS:%=$(TSS_DIR)/%)
 
diff --git a/libxz/Makefile.inc b/libxz/Makefile.inc
index 2987328..4fe7c3e 100644
--- a/libxz/Makefile.inc
+++ b/libxz/Makefile.inc
@@ -2,6 +2,6 @@ LIBXZ_SRCS = xz_dec_stream.c xz_dec_lzma2.c xz_crc32.c
 LIBXZ_OBJS = $(LIBXZ_SRCS:%.c=%.o)
 
 SUBDIRS += libxz
-LIBXZ = libxz/built-in.o
+LIBXZ = libxz/built-in.a
 
 $(LIBXZ): $(LIBXZ_OBJS:%=libxz/%)
diff --git a/platforms/Makefile.inc b/platforms/Makefile.inc
index 90cd0f1..3269532 100644
--- a/platforms/Makefile.inc
+++ b/platforms/Makefile.inc
@@ -1,7 +1,7 @@
 PLATDIR = platforms
 
 SUBDIRS += $(PLATDIR)
-PLATFORMS = $(PLATDIR)/built-in.o
+PLATFORMS = $(PLATDIR)/built-in.a
 
 include $(SRC)/$(PLATDIR)/ibm-fsp/Makefile.inc
 include $(SRC)/$(PLATDIR)/rhesus/Makefile.inc
diff --git a/platforms/astbmc/Makefile.inc b/platforms/astbmc/Makefile.inc
index 49292c1..d996536 100644
--- a/platforms/astbmc/Makefile.inc
+++ b/platforms/astbmc/Makefile.inc
@@ -6,6 +6,6 @@ ASTBMC_OBJS = pnor.o common.o slots.o \
 	      garrison.o barreleye.o \
 	      witherspoon.o zaius.o romulus.o p9dsu.o
 
-ASTBMC = $(PLATDIR)/astbmc/built-in.o
+ASTBMC = $(PLATDIR)/astbmc/built-in.a
 $(ASTBMC): $(ASTBMC_OBJS:%=$(PLATDIR)/astbmc/%)
 
diff --git a/platforms/ibm-fsp/Makefile.inc b/platforms/ibm-fsp/Makefile.inc
index e9daab2..c4b55a3 100644
--- a/platforms/ibm-fsp/Makefile.inc
+++ b/platforms/ibm-fsp/Makefile.inc
@@ -2,6 +2,6 @@ SUBDIRS += $(PLATDIR)/ibm-fsp
 
 IBM_FSP_OBJS = common.o lxvpd.o apollo.o apollo-pci.o \
 	       firenze.o firenze-pci.o zz.o
-IBM_FSP = $(PLATDIR)/ibm-fsp/built-in.o
+IBM_FSP = $(PLATDIR)/ibm-fsp/built-in.a
 $(IBM_FSP): $(IBM_FSP_OBJS:%=$(PLATDIR)/ibm-fsp/%)
 
diff --git a/platforms/mambo/Makefile.inc b/platforms/mambo/Makefile.inc
index f3023ef..b0e6b0c 100644
--- a/platforms/mambo/Makefile.inc
+++ b/platforms/mambo/Makefile.inc
@@ -1,6 +1,6 @@
 SUBDIRS += $(PLATDIR)/mambo
 
 MAMBO_OBJS = mambo.o console.o
-MAMBO = $(PLATDIR)/mambo/built-in.o
+MAMBO = $(PLATDIR)/mambo/built-in.a
 $(MAMBO): $(MAMBO_OBJS:%=$(PLATDIR)/mambo/%)
 
diff --git a/platforms/qemu/Makefile.inc b/platforms/qemu/Makefile.inc
index 11a44db..d4f988e 100644
--- a/platforms/qemu/Makefile.inc
+++ b/platforms/qemu/Makefile.inc
@@ -1,6 +1,6 @@
 SUBDIRS += $(PLATDIR)/qemu
 
 QEMU_OBJS = qemu.o
-QEMU = $(PLATDIR)/qemu/built-in.o
+QEMU = $(PLATDIR)/qemu/built-in.a
 $(QEMU): $(QEMU_OBJS:%=$(PLATDIR)/qemu/%)
 
diff --git a/platforms/rhesus/Makefile.inc b/platforms/rhesus/Makefile.inc
index 5899ca2..3a3fd87 100644
--- a/platforms/rhesus/Makefile.inc
+++ b/platforms/rhesus/Makefile.inc
@@ -1,6 +1,6 @@
 SUBDIRS += $(PLATDIR)/rhesus
 
 RHESUS_OBJS = rhesus.o
-RHESUS = $(PLATDIR)/rhesus/built-in.o
+RHESUS = $(PLATDIR)/rhesus/built-in.a
 $(RHESUS): $(RHESUS_OBJS:%=$(PLATDIR)/rhesus/%)