make hello_world relocatable with BOOT_INIT_BASE define

diff --git a/hello_world/Makefile b/hello_world/Makefile
index 230b2652dcede608962db2df889dc28a20f62bac..180f7b923106fe3e6b0df5e2918881e05fad472d 100644 (file)
--- a/hello_world/Makefile
+++ b/hello_world/Makefile
@@ -5,21 +5,33 @@ ifneq ("$(ARCH)", "ppc64le")
 endif
 endif
 
+BOOT_INIT_BASE ?= 0xf0000000 # at QSPI address
+# BOOT_INIT_BASE ?= 0xff000000   # at ROM hi address (with coldboot firmware)
+# BOOT_INIT_BASE ?= 0x0        # start at zero (usual)
+
 CC = $(CROSS_COMPILE)gcc
 LD = $(CROSS_COMPILE)ld
 OBJCOPY = $(CROSS_COMPILE)objcopy
 
-CFLAGS = -Os -g -Wall -std=c99 -mabi=elfv2 -msoft-float -mno-string -mno-multiple -mno-vsx -mno-altivec -mlittle-endian -fno-stack-protector -mstrict-align -ffreestanding -fdata-sections -ffunction-sections -I../include
+CFLAGS = -Os -g -Wall -std=c99 -mabi=elfv2 -msoft-float -mno-string \
+                -mno-multiple -mno-vsx -mno-altivec -mlittle-endian \
+                -fno-stack-protector -mstrict-align -ffreestanding \
+                -fdata-sections -ffunction-sections -I../include \
+            -DBOOT_INIT_BASE=$(BOOT_INIT_BASE) 
+
 ASFLAGS = $(CFLAGS)
-LDFLAGS = -T powerpc.lds
+LDFLAGS = -static -nostdlib -T powerpc.lds --gc-sections
 
 all: hello_world.hex
 
+powerpc.lds: powerpc.lds.S
+       $(CC) $(CFLAGS) -P -E powerpc.lds.S -o powerpc.lds
+
 console.o: ../lib/console.c
        $(CC) $(CPPFLAGS) $(CFLAGS) -c $< -o $@
 
-hello_world.elf: hello_world.o head.o console.o
-       $(LD) $(LDFLAGS) -o $@ $^
+hello_world.elf: hello_world.o head.o console.o powerpc.lds
+       $(LD) $(LDFLAGS) -o $@ hello_world.o head.o console.o 
 
 hello_world.bin: hello_world.elf
        $(OBJCOPY) -O binary $^ $@

diff --git a/hello_world/powerpc.lds.S b/hello_world/powerpc.lds.S
new file mode 100644 (file)
index 0000000..06cae4c
--- /dev/null
+++ b/hello_world/powerpc.lds.S
@@ -0,0 +1,16 @@
+SECTIONS
+{
+       . = BOOT_INIT_BASE;
+       _start = .;
+       start = _start;
+       . = BOOT_INIT_BASE;
+       .head : {
+               KEEP(*(.head))
+       }
+       . = BOOT_INIT_BASE + 0x1000;
+       .text : { *(.text) }
+       . = BOOT_INIT_BASE + 0x1800;
+       .data : { *(.data) }
+       .bss : { *(.bss) }
+}
+