GK SDK 源码库: XMIPCLinuxV100R005C00SPC030 (kernel/tools/open_source excluded)

2026-09-06 03:52:57 +08:00
commit b1928b41c0
21813 changed files with 4413081 additions and 0 deletions
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ *  armboot - Startup Code for ARM920 CPU-core
+ *
+ *  Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
+ *  Copyright (c) 2002	Alex Züpke <azu@sysgo.de>
+ *  Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
+ */
+
+#include <asm-offsets.h>
+#include <common.h>
+#include <config.h>
+
+/*
+ *************************************************************************
+ *
+ * Startup Code (called from the ARM reset exception vector)
+ *
+ * do important init only if we don't start from memory!
+ * relocate armboot to ram
+ * setup stack
+ * jump to second stage
+ *
+ *************************************************************************
+ */
+
+	.globl	reset
+
+reset:
+	/*
+	 * set the cpu to SVC32 mode
+	 */
+	mrs	r0, cpsr
+	bic	r0, r0, #0x1f
+	orr	r0, r0, #0xd3
+	msr	cpsr, r0
+
+#if	defined(CONFIG_AT91RM9200DK) || defined(CONFIG_AT91RM9200EK)
+	/*
+	 * relocate exception table
+	 */
+	ldr	r0, =_start
+	ldr	r1, =0x0
+	mov	r2, #16
+copyex:
+	subs	r2, r2, #1
+	ldr	r3, [r0], #4
+	str	r3, [r1], #4
+	bne	copyex
+#endif
+
+	/*
+	 * we do sys-critical inits only at reboot,
+	 * not when booting from ram!
+	 */
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+	bl	cpu_init_crit
+#endif
+
+	bl	_main
+
+/*------------------------------------------------------------------------------*/
+
+	.globl	c_runtime_cpu_setup
+c_runtime_cpu_setup:
+
+	mov	pc, lr
+
+/*
+ *************************************************************************
+ *
+ * CPU_init_critical registers
+ *
+ * setup important registers
+ * setup memory timing
+ *
+ *************************************************************************
+ */
+
+
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+cpu_init_crit:
+	/*
+	 * flush v4 I/D caches
+	 */
+	mov	r0, #0
+	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
+	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
+
+	/*
+	 * disable MMU stuff and caches
+	 */
+	mrc	p15, 0, r0, c1, c0, 0
+	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
+	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
+	orr	r0, r0, #0x00000002	@ set bit 1 (A) Align
+	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
+	mcr	p15, 0, r0, c1, c0, 0
+
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT_ONLY
+	/*
+	 * before relocating, we have to setup RAM timing
+	 * because memory timing is board-dependend, you will
+	 * find a lowlevel_init.S in your board directory.
+	 */
+	mov	ip, lr
+
+	bl	lowlevel_init
+	mov	lr, ip
+#endif
+	mov	pc, lr
+#endif /* CONFIG_SKIP_LOWLEVEL_INIT */