From 0253e0a89dfaf31a740927ce8f03e83efe4f1318 Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Tue, 17 Jan 2017 05:36:07 +0000
Subject: [PATCH] firmware: remove false dependency from runtime to ksupport.

This significantly speeds up no-change builds.
---
 artiq/firmware/runtime/kernel.rs | 12 +++++++++---
 artiq/runtime/Makefile           | 12 ++++++------
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/artiq/firmware/runtime/kernel.rs b/artiq/firmware/runtime/kernel.rs
index 5096badc1..dc36dfacc 100644
--- a/artiq/firmware/runtime/kernel.rs
+++ b/artiq/firmware/runtime/kernel.rs
@@ -12,9 +12,15 @@ pub unsafe fn start() {
 
     stop();
 
-    let ksupport_image = include_bytes!(concat!(env!("CARGO_TARGET_DIR"), "/../ksupport.elf"));
-    let ksupport_addr = (KERNELCPU_EXEC_ADDRESS - KSUPPORT_HEADER_SIZE) as *mut u8;
-    ptr::copy_nonoverlapping(ksupport_image.as_ptr(), ksupport_addr, ksupport_image.len());
+    extern {
+        static _binary_ksupport_elf_start: u8;
+        static _binary_ksupport_elf_end: u8;
+    }
+    let ksupport_start = &_binary_ksupport_elf_start as *const _;
+    let ksupport_end   = &_binary_ksupport_elf_end as *const _;
+    ptr::copy_nonoverlapping(ksupport_start,
+                             (KERNELCPU_EXEC_ADDRESS - KSUPPORT_HEADER_SIZE) as *mut u8,
+                             ksupport_end as usize - ksupport_start as usize);
 
     csr::kernel_cpu::reset_write(0);
 
diff --git a/artiq/runtime/Makefile b/artiq/runtime/Makefile
index 602774e83..1b6b09833 100644
--- a/artiq/runtime/Makefile
+++ b/artiq/runtime/Makefile
@@ -3,9 +3,6 @@ include $(MISOC_DIRECTORY)/software/common.mak
 
 PYTHON ?= python3.5
 
-OBJECTS := flash_storage.o main.o
-OBJECTS_KSUPPORT := ksupport_glue.o artiq_personality.o
-
 RUSTOUT := cargo/or1k-unknown-none/debug
 RUSTOUT_KSUPPORT := cargo-ksupport/or1k-unknown-none/debug
 
@@ -31,13 +28,13 @@ LDFLAGS += --gc-sections \
 all: runtime.bin runtime.fbi
 
 .PHONY: $(RUSTOUT)/libruntime.a
-$(RUSTOUT)/libruntime.a: ksupport.elf
+$(RUSTOUT)/libruntime.a:
 	RUSTFLAGS="-C target-feature=+mul,+div,+ffl1,+cmov,+addc -C opt-level=s -Cpanic=abort" \
 	CARGO_TARGET_DIR=$(realpath .)/cargo \
 		cargo build --target=or1k-unknown-none \
 			--manifest-path $(realpath $(RUNTIME_DIRECTORY)/../firmware/runtime/Cargo.toml)
 
-runtime.elf: $(OBJECTS) $(RUSTOUT)/libruntime.a
+runtime.elf: $(RUSTOUT)/libruntime.a flash_storage.o main.o ksupport_data.o
 	$(LD) $(LDFLAGS) \
 		-T $(RUNTIME_DIRECTORY)/runtime.ld \
 		-o $@ \
@@ -52,7 +49,7 @@ $(RUSTOUT_KSUPPORT)/libksupport.a:
 		cargo build --target=or1k-unknown-none \
 			--manifest-path $(realpath $(RUNTIME_DIRECTORY)/../firmware/libksupport/Cargo.toml)
 
-ksupport.elf: $(OBJECTS_KSUPPORT) $(RUSTOUT_KSUPPORT)/libksupport.a
+ksupport.elf: $(RUSTOUT_KSUPPORT)/libksupport.a ksupport_glue.o artiq_personality.o
 	$(LD) $(LDFLAGS) \
 		--eh-frame-hdr \
 		-T $(RUNTIME_DIRECTORY)/ksupport.ld \
@@ -68,6 +65,9 @@ ksupport.elf: $(OBJECTS_KSUPPORT) $(RUSTOUT_KSUPPORT)/libksupport.a
 	$(OBJCOPY) -O binary $< $@
 	@chmod -x $@
 
+%_data.o: %.elf
+	$(LD) -r -b binary -o $@ $<
+
 %.fbi: %.bin
 	@echo " MSCIMG  " $@ && $(PYTHON) -m misoc.tools.mkmscimg -f -o $@ $<