linking: lay the groundwork for a unified linking approach

Though coreboot started as x86 only, the current approach to x86
linking is out of the norm with respect to other architectures.
To start alleviating that the way ramstage is linked is partially
unified. A new file, program.ld, was added to provide a common way
to link stages by deferring to per-stage architectural overrides.
The previous ramstage.ld is no longer required.

Note that this change doesn't handle RELOCATABLE_RAMSTAGE
because that is handled by rmodule.ld. Future convergence
can be achieved, but for the time being that's being left out.

BUG=chrome-os-partner:44827
BRANCH=None
TEST=Built a myriad of boards.

Change-Id: I5d689bfa7e0e9aff3a148178515ef241b5f70661
Signed-off-by: Aaron Durbin <adubin@chromium.org>
Reviewed-on: http://review.coreboot.org/11507
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>
Reviewed-by: Julius Werner <jwerner@chromium.org>

2 files changed, 61 insertions, 46 deletions

diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc
index 85976672a8..cd2b70a81f 100644
--- a/src/lib/Makefile.inc
+++ b/src/lib/Makefile.inc
@@ -197,7 +197,8 @@ ifneq ($(CONFIG_ARCH_X86),y)
 bootblock-y += bootblock.ld
 romstage-y += romstage.ld
 endif
-ramstage-y += ramstage.ld
+
+ramstage-y += program.ld
 
 ifeq ($(CONFIG_RELOCATABLE_MODULES),y)
 ramstage-y += rmodule.c
diff --git a/src/lib/ramstage.ld b/src/lib/program.ld
index b224827590..1346eafbf8 100644
--- a/src/lib/ramstage.ld
+++ b/src/lib/program.ld
@@ -1,7 +1,7 @@
 /*
  * This file is part of the coreboot project.
  *
- * Copyright 2014 Google Inc.
+ * Copyright 2015 Google Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -17,6 +17,8 @@
  * Foundation, Inc.
  */
 
+#include <memlayout.h>
+
 /* This file is included inside a SECTIONS block */
 
 /* First we place the code and read only data (typically const declared).
@@ -24,19 +26,40 @@
  */
 .text : {
 	_program = .;
-	_ramstage = .;
 	_text = .;
 	*(.text._start);
 	*(.text.stage_entry);
 	*(.text);
 	*(.text.*);
-	. = ALIGN(16);
+
+#if ENV_RAMSTAGE || ENV_ROMSTAGE
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
+	_cbmem_init_hooks = .;
+	KEEP(*(.rodata.cbmem_init_hooks));
+	_ecbmem_init_hooks = .;
+#endif
+
+#if ENV_RAMSTAGE
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
+	_pci_drivers = .;
+	KEEP(*(.rodata.pci_driver));
+	_epci_drivers = .;
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
+	_cpu_drivers = .;
+	KEEP(*(.rodata.cpu_driver));
+	_ecpu_drivers = .;
+#endif
+
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
+	*(.rodata);
+	*(.rodata.*);
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
 	_etext = .;
 } : to_load
 
-#if IS_ENABLED(CONFIG_COVERAGE)
+#if ENV_RAMSTAGE && IS_ENABLED(CONFIG_COVERAGE)
 .ctors : {
-	. = ALIGN(0x100);
+	. = ALIGN(0x100)
 	__CTOR_LIST__ = .;
 	KEEP(*(.ctors));
 	LONG(0);
@@ -45,71 +68,62 @@
 }
 #endif
 
-/* TODO: align data sections to cache lines? (is that really useful?) */
-.rodata : {
-	_rodata = .;
-	. = ALIGN(8);
+/* Include data, bss, and heap in that order. Not defined for all stages. */
+#if ARCH_STAGE_HAS_DATA_SECTION
+.data : {
+	. = ALIGN(ARCH_CACHELINE_ALIGN_SIZE);
+	_data = .;
+	*(.data);
+	*(.data.*);
 
-	/* If any changes are made to the driver start/symbols or the
-	 * section names the equivalent changes need to made to
-	 * rmodule.ld. */
-	_pci_drivers = . ;
-	KEEP(*(.rodata.pci_driver));
-	_epci_drivers = . ;
-	_cpu_drivers = . ;
-	KEEP(*(.rodata.cpu_driver));
-	_ecpu_drivers = . ;
+#ifdef __PRE_RAM__
+	PROVIDE(_preram_cbmem_console = .);
+	PROVIDE(_epreram_cbmem_console = _preram_cbmem_console);
+#elif ENV_RAMSTAGE
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
 	_bs_init_begin = .;
 	KEEP(*(.bs_init));
 	LONG(0);
 	LONG(0);
-	_bs_init_end = .;
-	_cbmem_init_hooks = .;
-	KEEP(*(.rodata.cbmem_init_hooks));
-	_ecbmem_init_hooks = .;
-
-	*(.rodata)
-	*(.rodata.*)
-	/* kevinh/Ispiri - Added an align, because the objcopy tool
-	 * incorrectly converts sections that are not long word aligned.
-	 */
-	 . = ALIGN(8);
-
-	_erodata = .;
-}
+	_ebs_init_begin = .;
+#endif
 
-.data : {
-	/* Move to different cache line to avoid false sharing with .rodata. */
-	. = ALIGN(64);	/* May not be actual line size, not that important. */
-	_data = .;
-	*(.data)
-	*(.data.*)
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
 	_edata = .;
 }
+#endif
 
-.bss . : {
+#if ARCH_STAGE_HAS_BSS_SECTION
+.bss : {
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
 	_bss = .;
 	*(.bss)
 	*(.bss.*)
 	*(.sbss)
 	*(.sbss.*)
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
 	_ebss = .;
 }
+#endif
 
-.heap . : {
+#if ARCH_STAGE_HAS_HEAP_SECTION
+.heap : {
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
 	_heap = .;
-	/* Reserve CONFIG_HEAP_SIZE bytes for the heap */
-	. += CONFIG_HEAP_SIZE ;
-	. = ALIGN(4);
+	. += CONFIG_HEAP_SIZE;
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
 	_eheap = .;
-	_eramstage = .;
-	_eprogram = .;
 }
+#endif
+
+_eprogram = .;
 
 /* Discard the sections we don't need/want */
 
 /DISCARD/ : {
 	*(.comment)
+	*(.comment.*)
 	*(.note)
 	*(.note.*)
+	*(.eh_frame);
 }