ARC: Build system: Makefiles, Kconfig, Linker script

Arnd in his review pointed out that arch Kconfig organisation has several
deficiencies:

* Build time entries for things which can be runtime extracted from DT
  (e.g. SDRAM size, core clk frequency..)
* Not multi-platform-image-build friendly (choice .. endchoice constructs)
* cpu variants support (750/770) is exclusive.

The first 2 have been fixed in subsequent patches.
Due to the nature of the 750 and 770, it is not possible to build for
both together, w/o special runtime glue code which would hurt
performance.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

arch/arc/kernel/Makefile

@@ -0,0 +1,16 @@
+#
+# Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+obj-y	:= arcksyms.o setup.o irq.o time.o reset.o ptrace.o entry.o process.o
+obj-y	+= signal.o traps.o sys.o troubleshoot.o stacktrace.o clk.o
+
+obj-$(CONFIG_ARC_FPU_SAVE_RESTORE)	+= fpu.o
+CFLAGS_fpu.o   += -mdpfp
+
+obj-y += ctx_sw_asm.o
+
+extra-y := vmlinux.lds head.o

arch/arc/kernel/arcksyms.c

@@ -0,0 +1,56 @@
+/*
+ * arcksyms.c - Exporting symbols not exportable from their own sources
+ *
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+
+/* libgcc functions, not part of kernel sources */
+extern void __ashldi3(void);
+extern void __ashrdi3(void);
+extern void __divsi3(void);
+extern void __divsf3(void);
+extern void __lshrdi3(void);
+extern void __modsi3(void);
+extern void __muldi3(void);
+extern void __ucmpdi2(void);
+extern void __udivsi3(void);
+extern void __umodsi3(void);
+extern void __cmpdi2(void);
+extern void __fixunsdfsi(void);
+extern void __muldf3(void);
+extern void __divdf3(void);
+extern void __floatunsidf(void);
+extern void __floatunsisf(void);
+
+EXPORT_SYMBOL(__ashldi3);
+EXPORT_SYMBOL(__ashrdi3);
+EXPORT_SYMBOL(__divsi3);
+EXPORT_SYMBOL(__divsf3);
+EXPORT_SYMBOL(__lshrdi3);
+EXPORT_SYMBOL(__modsi3);
+EXPORT_SYMBOL(__muldi3);
+EXPORT_SYMBOL(__ucmpdi2);
+EXPORT_SYMBOL(__udivsi3);
+EXPORT_SYMBOL(__umodsi3);
+EXPORT_SYMBOL(__cmpdi2);
+EXPORT_SYMBOL(__fixunsdfsi);
+EXPORT_SYMBOL(__muldf3);
+EXPORT_SYMBOL(__divdf3);
+EXPORT_SYMBOL(__floatunsidf);
+EXPORT_SYMBOL(__floatunsisf);
+
+/* ARC optimised assembler routines */
+EXPORT_SYMBOL(memset);
+EXPORT_SYMBOL(memcpy);
+EXPORT_SYMBOL(memcmp);
+EXPORT_SYMBOL(strchr);
+EXPORT_SYMBOL(strcpy);
+EXPORT_SYMBOL(strcmp);
+EXPORT_SYMBOL(strlen);

arch/arc/kernel/asm-offsets.c

@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/thread_info.h>
+#include <linux/kbuild.h>
+#include <asm/hardirq.h>
+#include <asm/page.h>
+#include <asm/ptrace.h>
+
+int main(void)
+{
+	DEFINE(TASK_THREAD, offsetof(struct task_struct, thread));
+	DEFINE(TASK_THREAD_INFO, offsetof(struct task_struct, stack));
+
+	BLANK();
+
+	DEFINE(THREAD_KSP, offsetof(struct thread_struct, ksp));
+	DEFINE(THREAD_CALLEE_REG, offsetof(struct thread_struct, callee_reg));
+	DEFINE(THREAD_FAULT_ADDR,
+	       offsetof(struct thread_struct, fault_address));
+
+	BLANK();
+
+	DEFINE(THREAD_INFO_FLAGS, offsetof(struct thread_info, flags));
+	DEFINE(THREAD_INFO_PREEMPT_COUNT,
+	       offsetof(struct thread_info, preempt_count));
+
+	BLANK();
+
+	DEFINE(TASK_ACT_MM, offsetof(struct task_struct, active_mm));
+	DEFINE(TASK_TGID, offsetof(struct task_struct, tgid));
+
+	DEFINE(MM_CTXT, offsetof(struct mm_struct, context));
+	DEFINE(MM_PGD, offsetof(struct mm_struct, pgd));
+
+	DEFINE(MM_CTXT_ASID, offsetof(mm_context_t, asid));
+
+	BLANK();
+
+	DEFINE(PT_status32, offsetof(struct pt_regs, status32));
+	DEFINE(PT_orig_r8, offsetof(struct pt_regs, orig_r8));
+	DEFINE(PT_sp, offsetof(struct pt_regs, sp));
+	DEFINE(PT_r0, offsetof(struct pt_regs, r0));
+	DEFINE(PT_r1, offsetof(struct pt_regs, r1));
+	DEFINE(PT_r2, offsetof(struct pt_regs, r2));
+	DEFINE(PT_r3, offsetof(struct pt_regs, r3));
+	DEFINE(PT_r4, offsetof(struct pt_regs, r4));
+	DEFINE(PT_r5, offsetof(struct pt_regs, r5));
+	DEFINE(PT_r6, offsetof(struct pt_regs, r6));
+	DEFINE(PT_r7, offsetof(struct pt_regs, r7));
+
+	return 0;
+}

arch/arc/kernel/vmlinux.lds.S

@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <asm-generic/vmlinux.lds.h>
+#include <asm/cache.h>
+#include <asm/page.h>
+#include <asm/thread_info.h>
+#include <plat/memmap.h>
+
+OUTPUT_ARCH(arc)
+ENTRY(_stext)
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+jiffies = jiffies_64 + 4;
+#else
+jiffies = jiffies_64;
+#endif
+
+SECTIONS
+{
+	. = CONFIG_LINUX_LINK_BASE;
+
+	_int_vec_base_lds = .;
+	.vector : {
+		*(.vector)
+		. = ALIGN(PAGE_SIZE);
+	}
+
+	/*
+	 * The reason for having a seperate subsection .init.ramfs is to
+	 * prevent objump from including it in kernel dumps
+	 *
+	 * Reason for having .init.ramfs above .init is to make sure that the
+	 * binary blob is tucked away to one side, reducing the displacement
+	 * between .init.text and .text, avoiding any possible relocation
+	 * errors because of calls from .init.text to .text
+	 * Yes such calls do exist. e.g.
+	 *	decompress_inflate.c:gunzip( ) -> zlib_inflate_workspace( )
+	 */
+
+	__init_begin = .;
+
+	.init.ramfs : { INIT_RAM_FS }
+
+	. = ALIGN(PAGE_SIZE);
+	_stext = .;
+
+	HEAD_TEXT_SECTION
+	INIT_TEXT_SECTION(L1_CACHE_BYTES)
+
+	/* INIT_DATA_SECTION open-coded: special INIT_RAM_FS handling */
+	.init.data : {
+		INIT_DATA
+		INIT_SETUP(L1_CACHE_BYTES)
+		INIT_CALLS
+		CON_INITCALL
+		SECURITY_INITCALL
+	}
+
+	PERCPU_SECTION(L1_CACHE_BYTES)
+
+	/*
+	 * .exit.text is discard at runtime, not link time, to deal with
+	 * references from .debug_frame
+	 * It will be init freed, being inside [__init_start : __init_end]
+	 */
+	.exit.text : { EXIT_TEXT }
+	.exit.data : { EXIT_DATA }
+
+	. = ALIGN(PAGE_SIZE);
+	__init_end = .;
+
+	.text : {
+		_text = .;
+		TEXT_TEXT
+		SCHED_TEXT
+		LOCK_TEXT
+		KPROBES_TEXT
+		*(.fixup)
+		*(.gnu.warning)
+	}
+	EXCEPTION_TABLE(L1_CACHE_BYTES)
+	_etext = .;
+
+	_sdata = .;
+	RO_DATA_SECTION(PAGE_SIZE)
+
+	/*
+	 * 1. this is .data essentially
+	 * 2. THREAD_SIZE for init.task, must be kernel-stk sz aligned
+	 */
+	RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+
+	_edata = .;
+
+	BSS_SECTION(0, 0, 0)
+
+	NOTES
+
+	. = ALIGN(PAGE_SIZE);
+	_end = . ;
+
+	STABS_DEBUG
+	DWARF_DEBUG
+	DISCARDS
+
+	.arcextmap 0 : {
+		*(.gnu.linkonce.arcextmap.*)
+		*(.arcextmap.*)
+	}
+}