nios2: Kernel booting and initialization

This patch adds the kernel booting and the initial setup code.

Signed-off-by: Ley Foon Tan <lftan@altera.com>

1 files changed, 120 insertions, 0 deletions

diff --git a/arch/nios2/include/asm/entry.h b/arch/nios2/include/asm/entry.h
new file mode 100644
index 000000000000..cf37f55efbc2
--- /dev/null
+++ b/arch/nios2/include/asm/entry.h
@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
+ * Copyright (C) 2004 Microtronix Datacom Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef _ASM_NIOS2_ENTRY_H
+#define _ASM_NIOS2_ENTRY_H
+
+#ifdef __ASSEMBLY__
+
+#include <asm/processor.h>
+#include <asm/registers.h>
+#include <asm/asm-offsets.h>
+
+/*
+ * Standard Nios2 interrupt entry and exit macros.
+ * Must be called with interrupts disabled.
+ */
+.macro SAVE_ALL
+	rdctl	r24, estatus
+	andi	r24, r24, ESTATUS_EU
+	beq	r24, r0, 1f /* In supervisor mode, already on kernel stack */
+
+	movia	r24, _current_thread	/* Switch to current kernel stack */
+	ldw	r24, 0(r24)		/* using the thread_info */
+	addi	r24, r24, THREAD_SIZE-PT_REGS_SIZE
+	stw	sp, PT_SP(r24)		/* Save user stack before changing */
+	mov	sp, r24
+	br	2f
+
+1 :	mov	r24, sp
+	addi	sp, sp, -PT_REGS_SIZE	/* Backup the kernel stack pointer */
+	stw	r24, PT_SP(sp)
+2 :	stw	r1, PT_R1(sp)
+	stw	r2, PT_R2(sp)
+	stw	r3, PT_R3(sp)
+	stw	r4, PT_R4(sp)
+	stw	r5, PT_R5(sp)
+	stw	r6, PT_R6(sp)
+	stw	r7, PT_R7(sp)
+	stw	r8, PT_R8(sp)
+	stw	r9, PT_R9(sp)
+	stw	r10, PT_R10(sp)
+	stw	r11, PT_R11(sp)
+	stw	r12, PT_R12(sp)
+	stw	r13, PT_R13(sp)
+	stw	r14, PT_R14(sp)
+	stw	r15, PT_R15(sp)
+	stw	r2, PT_ORIG_R2(sp)
+	stw	r7, PT_ORIG_R7(sp)
+
+	stw	ra, PT_RA(sp)
+	stw	fp, PT_FP(sp)
+	stw	gp, PT_GP(sp)
+	rdctl	r24, estatus
+	stw	r24, PT_ESTATUS(sp)
+	stw	ea, PT_EA(sp)
+.endm
+
+.macro RESTORE_ALL
+	ldw	r1, PT_R1(sp)		/* Restore registers */
+	ldw	r2, PT_R2(sp)
+	ldw	r3, PT_R3(sp)
+	ldw	r4, PT_R4(sp)
+	ldw	r5, PT_R5(sp)
+	ldw	r6, PT_R6(sp)
+	ldw	r7, PT_R7(sp)
+	ldw	r8, PT_R8(sp)
+	ldw	r9, PT_R9(sp)
+	ldw	r10, PT_R10(sp)
+	ldw	r11, PT_R11(sp)
+	ldw	r12, PT_R12(sp)
+	ldw	r13, PT_R13(sp)
+	ldw	r14, PT_R14(sp)
+	ldw	r15, PT_R15(sp)
+	ldw	ra, PT_RA(sp)
+	ldw	fp, PT_FP(sp)
+	ldw	gp, PT_GP(sp)
+	ldw	r24, PT_ESTATUS(sp)
+	wrctl	estatus, r24
+	ldw	ea, PT_EA(sp)
+	ldw	sp, PT_SP(sp)		/* Restore sp last */
+.endm
+
+.macro	SAVE_SWITCH_STACK
+	addi	sp, sp, -SWITCH_STACK_SIZE
+	stw	r16, SW_R16(sp)
+	stw	r17, SW_R17(sp)
+	stw	r18, SW_R18(sp)
+	stw	r19, SW_R19(sp)
+	stw	r20, SW_R20(sp)
+	stw	r21, SW_R21(sp)
+	stw	r22, SW_R22(sp)
+	stw	r23, SW_R23(sp)
+	stw	fp, SW_FP(sp)
+	stw	gp, SW_GP(sp)
+	stw	ra, SW_RA(sp)
+.endm
+
+.macro	RESTORE_SWITCH_STACK
+	ldw	r16, SW_R16(sp)
+	ldw	r17, SW_R17(sp)
+	ldw	r18, SW_R18(sp)
+	ldw	r19, SW_R19(sp)
+	ldw	r20, SW_R20(sp)
+	ldw	r21, SW_R21(sp)
+	ldw	r22, SW_R22(sp)
+	ldw	r23, SW_R23(sp)
+	ldw	fp, SW_FP(sp)
+	ldw	gp, SW_GP(sp)
+	ldw	ra, SW_RA(sp)
+	addi	sp, sp, SWITCH_STACK_SIZE
+.endm
+
+#endif /* __ASSEMBLY__ */
+#endif /* _ASM_NIOS2_ENTRY_H */