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>
diff --git a/src/lib/program.ld b/src/lib/program.ld
new file mode 100644
index 0000000..1346eaf
--- /dev/null
+++ b/src/lib/program.ld
@@ -0,0 +1,129 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * 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
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * 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).
+ * This could theoretically be placed in rom.
+ */
+.text : {
+	_program = .;
+	_text = .;
+	*(.text._start);
+	*(.text.stage_entry);
+	*(.text);
+	*(.text.*);
+
+#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 ENV_RAMSTAGE && IS_ENABLED(CONFIG_COVERAGE)
+.ctors : {
+	. = ALIGN(0x100)
+	__CTOR_LIST__ = .;
+	KEEP(*(.ctors));
+	LONG(0);
+	LONG(0);
+	__CTOR_END__ = .;
+}
+#endif
+
+/* 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.*);
+
+#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);
+	_ebs_init_begin = .;
+#endif
+
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
+	_edata = .;
+}
+#endif
+
+#if ARCH_STAGE_HAS_BSS_SECTION
+.bss : {
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
+	_bss = .;
+	*(.bss)
+	*(.bss.*)
+	*(.sbss)
+	*(.sbss.*)
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
+	_ebss = .;
+}
+#endif
+
+#if ARCH_STAGE_HAS_HEAP_SECTION
+.heap : {
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
+	_heap = .;
+	. += CONFIG_HEAP_SIZE;
+	. = ALIGN(ARCH_POINTER_ALIGN_SIZE);
+	_eheap = .;
+}
+#endif
+
+_eprogram = .;
+
+/* Discard the sections we don't need/want */
+
+/DISCARD/ : {
+	*(.comment)
+	*(.comment.*)
+	*(.note)
+	*(.note.*)
+	*(.eh_frame);
+}