[ARM] nommu: start-up code

This patch adds nommu version start-up code head-nommu.S.
The common part of the start-up codes is moved to head-common.S.

Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 83 insertions, 0 deletions

diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
new file mode 100644
index 0000000..b093ab8
--- /dev/null
+++ b/arch/arm/kernel/head-nommu.S
@@ -0,0 +1,83 @@
+/*
+ *  linux/arch/arm/kernel/head-nommu.S
+ *
+ *  Copyright (C) 1994-2002 Russell King
+ *  Copyright (C) 2003-2006 Hyok S. Choi
+ *
+ * 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.
+ *
+ *  Common kernel startup code (non-paged MM)
+ *    for 32-bit CPUs which has a process ID register(CP15).
+ *
+ */
+#include <linux/config.h>
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+#include <asm/assembler.h>
+#include <asm/mach-types.h>
+#include <asm/procinfo.h>
+#include <asm/ptrace.h>
+#include <asm/constants.h>
+#include <asm/system.h>
+
+#define PROCINFO_INITFUNC       12
+
+/*
+ * Kernel startup entry point.
+ * ---------------------------
+ *
+ * This is normally called from the decompressor code.  The requirements
+ * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
+ * r1 = machine nr.
+ *
+ * See linux/arch/arm/tools/mach-types for the complete list of machine
+ * numbers for r1.
+ *
+ */
+	__INIT
+	.type	stext, %function
+ENTRY(stext)
+	msr	cpsr_c, #PSR_F_BIT | PSR_I_BIT | MODE_SVC @ ensure svc mode
+						@ and irqs disabled
+	mrc	p15, 0, r9, c0, c0		@ get processor id
+	bl	__lookup_processor_type		@ r5=procinfo r9=cpuid
+	movs	r10, r5				@ invalid processor (r5=0)?
+	beq	__error_p				@ yes, error 'p'
+	bl	__lookup_machine_type		@ r5=machinfo
+	movs	r8, r5				@ invalid machine (r5=0)?
+	beq	__error_a			@ yes, error 'a'
+
+	ldr	r13, __switch_data		@ address to jump to after
+						@ the initialization is done
+	adr	lr, __after_proc_init		@ return (PIC) address
+	add	pc, r10, #PROCINFO_INITFUNC
+
+/*
+ * Set the Control Register and Read the process ID.
+ */
+	.type	__after_proc_init, %function
+__after_proc_init:
+	mrc	p15, 0, r0, c1, c0, 0		@ read control reg
+#ifdef CONFIG_ALIGNMENT_TRAP
+	orr	r0, r0, #CR_A
+#else
+	bic	r0, r0, #CR_A
+#endif
+#ifdef CONFIG_CPU_DCACHE_DISABLE
+	bic	r0, r0, #CR_C
+#endif
+#ifdef CONFIG_CPU_BPREDICT_DISABLE
+	bic	r0, r0, #CR_Z
+#endif
+#ifdef CONFIG_CPU_ICACHE_DISABLE
+	bic	r0, r0, #CR_I
+#endif
+	mcr	p15, 0, r0, c1, c0, 0		@ write control reg
+
+	mov	pc, r13				@ clear the BSS and jump
+						@ to start_kernel
+
+#include "head-common.S"