atsamd: Use local linker script

Use a local linker script instead of the linker script provided by
Atmel.  This will allow Klipper to use dynamic memory allocation.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

3 files changed, 84 insertions, 9 deletions

diff --git a/src/atsamd/Kconfig b/src/atsamd/Kconfig
index c77f57bb..236a2a0e 100644
--- a/src/atsamd/Kconfig
+++ b/src/atsamd/Kconfig
@@ -53,6 +53,22 @@ config CLOCK_FREQ
     default 48000000 if MACH_SAMD21
     default 120000000 if MACH_SAMD51
 
+config FLASH_SIZE
+    hex
+    default 0x40000 if MACH_SAMD21G18
+    default 0x80000 if MACH_SAMD51G19 || MACH_SAMD51J19 || MACH_SAMD51N19
+    default 0x100000 if MACH_SAMD51P20
+
+config RAM_SIZE
+    hex
+    default 0x8000 if MACH_SAMD21G18
+    default 0x30000 if MACH_SAMD51G19 || MACH_SAMD51J19 || MACH_SAMD51N19
+    default 0x40000 if MACH_SAMD51P20
+
+config STACK_SIZE
+    int
+    default 512
+
 choice
     prompt "Clock Reference"
     config CLOCK_REF_X32K
diff --git a/src/atsamd/Makefile b/src/atsamd/Makefile
index 3b749d5d..0ef2aa91 100644
--- a/src/atsamd/Makefile
+++ b/src/atsamd/Makefile
@@ -37,17 +37,13 @@ src-$(CONFIG_MACH_SAMD51) += atsamd/samd51_clock.c generic/armcm_timer.c
 src-$(CONFIG_MACH_SAMD51) += ../lib/samd51/samd51a/gcc/gcc/startup_samd51.c
 
 # Support bootloader offset address
-target-y := $(OUT)samd.ld $(target-y)
+target-y := $(target-y)
 
-ldfile-$(CONFIG_MACH_SAMD21G18) := lib/samd21/samd21a/gcc/gcc/samd21g18a_flash.ld
-ldfile-$(CONFIG_MACH_SAMD51G19) := lib/samd51/samd51a/gcc/gcc/samd51g19a_flash.ld
-ldfile-$(CONFIG_MACH_SAMD51J19) := lib/samd51/samd51a/gcc/gcc/samd51j19a_flash.ld
-ldfile-$(CONFIG_MACH_SAMD51N19) := lib/samd51/samd51a/gcc/gcc/samd51n19a_flash.ld
-ldfile-$(CONFIG_MACH_SAMD51P20) := lib/samd51/samd51a/gcc/gcc/samd51p20a_flash.ld
-
-$(OUT)samd.ld: $(ldfile-y) $(OUT)board-link
+$(OUT)samd.ld: src/atsamd/samd.lds.S $(OUT)board-link
 	@echo "  Preprocessing $@"
-	$(Q)$(CPP) -P -MD -MT $@ -DFLASH_START=$(CONFIG_FLASH_START) $< -o $@
+	$(Q)$(CPP) -I$(OUT) -P -MD -MT $@ $< -o $@
+
+$(OUT)klipper.elf: $(OUT)samd.ld
 
 # Build the additional hex and bin output files
 target-y += $(OUT)klipper.bin $(OUT)klipper.elf.hex
diff --git a/src/atsamd/samd.lds.S b/src/atsamd/samd.lds.S
new file mode 100644
index 00000000..62e9d6ad
--- /dev/null
+++ b/src/atsamd/samd.lds.S
@@ -0,0 +1,63 @@
+/* Linker script for atsamd chips
+ *
+ * Copyright (C) 2019  Kevin O'Connor <kevin@koconnor.net>
+ *
+ * This file may be distributed under the terms of the GNU GPLv3 license.
+ */
+
+#include "autoconf.h"
+
+OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
+OUTPUT_ARCH(arm)
+
+MEMORY
+{
+  rom (rx) : ORIGIN = CONFIG_FLASH_START , LENGTH = CONFIG_FLASH_SIZE
+  ram (rwx) : ORIGIN = 0x20000000, LENGTH = CONFIG_RAM_SIZE
+}
+
+SECTIONS
+{
+    .text : {
+        . = ALIGN(4);
+        _sfixed = .;
+        KEEP(*(.vectors .vectors.*))
+        *(.text .text.*)
+        *(.rodata .rodata*)
+
+        . = ALIGN(4);
+        KEEP(*(.init))
+        . = ALIGN(4);
+        KEEP(*(.fini))
+    } > rom
+
+    . = ALIGN(4);
+    _etext = .;
+
+    .relocate : AT (_etext)
+    {
+        . = ALIGN(4);
+        _srelocate = .;
+        *(.ramfunc .ramfunc.*);
+        *(.data .data.*);
+        . = ALIGN(4);
+        _erelocate = .;
+    } > ram
+
+    .bss (NOLOAD) :
+    {
+        . = ALIGN(4);
+        _szero = .;
+        *(.bss .bss.*)
+        *(COMMON)
+        . = ALIGN(4);
+        _ezero = .;
+    } > ram
+
+    _sstack = 0x20000000 + CONFIG_RAM_SIZE - CONFIG_STACK_SIZE ;
+    .stack _sstack (NOLOAD) :
+    {
+        . = . + CONFIG_STACK_SIZE;
+        _estack = .;
+    } > ram
+}