[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 000000000000..b093ab8738b5
--- /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"