From 21b21d3d5c7feb1ece4c8ea3d495e03c502450ea Mon Sep 17 00:00:00 2001
From: hackbard <hackbard@staubsauger.localdomain>
Date: Fri, 31 Aug 2007 10:06:14 +0200
Subject: [PATCH] added initial linker script and tartup asm code

---
 betty/Makefile       | 37 ++++++++++++++++++++++------------
 betty/lpc2220_ram.ld | 29 +++++++++++++++++++++++++++
 betty/lpc2220_rom.ld | 43 ++++++++++++++++++++++++++++++++++++++++
 betty/startup.s      | 47 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 143 insertions(+), 13 deletions(-)
 create mode 100644 betty/lpc2220_ram.ld
 create mode 100644 betty/lpc2220_rom.ld
 create mode 100644 betty/startup.s

diff --git a/betty/Makefile b/betty/Makefile
index b5b6a5f..dfd3fee 100644
--- a/betty/Makefile
+++ b/betty/Makefile
@@ -5,12 +5,18 @@ CFLAGS = -Wall
 # cross build
 ARCH = arm-elf
 CROSS_CC = $(ARCH)-gcc
+CROSS_AS = $(ARCH)-as
+CROSS_LD = $(ARCH)-ld
 CROSS_OBJCOPY = $(ARCH)-objcopy
-CROSS_CFLAGS = -Wall -Os -mcpu=arm7tdmi-s -nostartfiles -nostdlib
+CROSS_OPTS = -mcpu=arm7tdmi-s
+CROSS_CFLAGS = $(CROSS_OPTS) -Wall -Os
+CROSS_ASLAGS = $(CROSS_OPTS) --gstabs
+CROSS_RAM_LDFLAGS = -Tlpc2220_ram.ld -nostartfiles -nostdlib
+CROSS_ROM_LDFLAGS = -Tlpc2220_rom.ld -nostartfiles -nostdlib
 
 # build objects
 HOST_TARGET = lpcload fwdump
-CROSS_TARGET = fwbc.hex fwflash.hex
+CROSS_TARGET = fwbc.hex fwflash.hex fwflash.elf # debug: .elf for objdump
 
 # all projects
 all: $(HOST_TARGET) $(CROSS_TARGET)
@@ -18,22 +24,27 @@ all: $(HOST_TARGET) $(CROSS_TARGET)
 # arm code
 arm: arm_clean $(CROSS_TARGET)
 
-# fwbc
-fwbc:
-	$(CROSS_CC) $(CROSS_CFLAGS) -c fwbc.c -o fwbc
+# .o out of .c
+%.o: %.c
+	$(CROSS_CC) -c $(CROSS_CFLAGS) -o $@ $<
 
-fwbc.hex: fwbc
-	$(CROSS_OBJCOPY) -O ihex fwbc fwbc.hex
+# .o out of .s
+%.o: %.s
+	$(CROSS_AS) $(CROSS_ASLAGS) -o $@ $<
 
-# fwflash
-fwflash:
-	$(CROSS_CC) $(CROSS_CFLAGS) -c fwflash.c -o fwflash
+# .elf out of .o
+%.elf: %.o startup.o
+	$(CROSS_LD) $(CROSS_RAM_LDFLAGS) startup.o -o $@ $<
 
-fwflash.hex: fwflash
-	$(CROSS_OBJCOPY) -O ihex fwflash fwflash.hex
+# .hex out of .elf
+%.hex: %.elf
+	$(CROSS_OBJCOPY) -O ihex $< $@
 
+# host clean
 clean:
 	rm -f lpcload fwdump
 
+# arm clean
 arm_clean:
-	rm -f $(CROSS_TARGET) fwbc fwflash
+	rm -vf *.o *.hex *.elf
+
diff --git a/betty/lpc2220_ram.ld b/betty/lpc2220_ram.ld
new file mode 100644
index 0000000..c6fd14d
--- /dev/null
+++ b/betty/lpc2220_ram.ld
@@ -0,0 +1,29 @@
+/*
+ * lpc2220_ram.ld - linker script for the lpc2220 device (->ram)
+ *
+ * author: hackbard@hackdaworld.org
+ *
+ */
+
+SECTIONS {
+	. = 0x40000200;
+	.text . : {
+		startup.o(.text)	/* startup code */
+		*(.text)		/* all remaining code */
+		*(.glue_7)		/* glue code */
+		*(.glue_7t)		/* glue code */
+	}
+
+	. = ALIGN(4);
+
+	.rodata : { *(.rodata) }	/* read only data */
+
+	. = ALIGN(4);
+
+	.data : { *(.data) }		/* initialized data */
+
+	. = ALIGN(4);
+
+	.bss : { *(.bss) }		/* uninitialized data */
+}
+
diff --git a/betty/lpc2220_rom.ld b/betty/lpc2220_rom.ld
new file mode 100644
index 0000000..11fa38d
--- /dev/null
+++ b/betty/lpc2220_rom.ld
@@ -0,0 +1,43 @@
+/*
+ * lpc2220_rom.ld - linker script for the lpc2220 device (->rom)
+ *
+ * author: hackbard@hackdaworld.org
+ *
+ */
+
+/* memory definitions */
+
+MEMORY {
+	FLASH_BANK0 (rx) : ORIGIN=0x80000000, LENGTH=0x00100000
+	FLASH_BANK2 (rx) : ORIGIN=0x82000000, LENGTH=0x00100000
+	RAM (rw) : ORIGIN=0x40000000, LENGTH=0x00010000
+}
+
+/* section definitions */
+
+SECTIONS {
+	
+	/* startup and user code (.text) */
+	.text : {
+		startup.o(.text)	// startup code
+		*(.text)		// our code
+		*(.glue_7)		// glue code
+		*(.glue_7t)		// glue code
+	} > FLASH_BANK0
+
+	. = ALIGN(4)
+
+	/* read only data */
+	.rodata : { *(.rodata) } > FLASH_BANK0
+
+	. = ALIGN(4)
+
+	/* initialized data */
+	.data : { *(.data) } > RAM
+
+	. = ALIGN(4);
+
+	/* uninitialized data */
+	.bss : { *(.bss) } > RAM
+}
+
diff --git a/betty/startup.s b/betty/startup.s
new file mode 100644
index 0000000..bc4ff41
--- /dev/null
+++ b/betty/startup.s
@@ -0,0 +1,47 @@
+#
+# startup.s - starup code for the lpc2220
+#
+# author: hackbard@hackdaworld.org
+#
+
+#
+# some definitions
+#
+
+# sram
+
+.equ	sram_size,	(64*1024)
+.equ	sram_addr,	0x40000000
+.equ	sram_top,	(sram_addr+sram_size-4)
+
+# stack
+
+.equ	stack_size,	(2*1024)
+.equ	stack_top,	sram_top
+.equ	stack_limit,	(sram_top-stack_size)
+
+#
+# the startup code
+#
+
+.text
+.arm
+
+	# init stack pointer
+
+	ldr r0, =sram_top
+	mov sp, r0
+	ldr r0, =stack_limit
+	mov sl, r0
+
+	# jump to c code
+
+	adr lr, loop_forever
+	mov r0, #0
+	mov r1, #0
+	ldr r2, =main
+	bx r2
+
+loop_forever:
+	b loop_forever
+
-- 
2.20.1