Add test tool to exercise SDRAM accesses in burst mode

(as standalone program, MPC8xx/PowerPC only)

1 files changed, 170 insertions, 0 deletions

diff --git a/examples/test_burst_lib.S b/examples/test_burst_lib.S
new file mode 100644
index 0000000..5bb4981
--- /dev/null
+++ b/examples/test_burst_lib.S
@@ -0,0 +1,170 @@
+/*
+ * (C) Copyright 2005
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <config.h>
+
+#include <ppc_asm.tmpl>
+#include <ppc_defs.h>
+#include <asm/cache.h>
+#include <asm/mmu.h>
+#include "test_burst.h"
+
+	.text
+/*
+ *	void mmu_init(void);
+ *
+ *	This function turns the MMU on
+ *
+ *	Three 8 MByte regions are mapped 1:1, uncached
+ *	- SDRAM lower 8 MByte
+ *	- SDRAM higher 8 MByte
+ *	- IMMR
+ */
+	.global mmu_init
+mmu_init:
+	tlbia			/* Invalidate all TLB entries */
+	li	r8, 0
+	mtspr	MI_CTR, r8	/* Set instruction control to zero */
+	lis	r8, MD_RESETVAL@h
+	mtspr	MD_CTR, r8	/* Set data TLB control */
+
+	/* Now map the lower 8 Meg into the TLBs.  For this quick hack,
+	 * we can load the instruction and data TLB registers with the
+	 * same values.
+	 */
+	li	r8, MI_EVALID		/* Create EPN for address 0 */
+	mtspr	MI_EPN, r8
+	mtspr	MD_EPN, r8
+	li	r8, MI_PS8MEG		/* Set 8M byte page */
+	ori	r8, r8, MI_SVALID	/* Make it valid */
+	mtspr	MI_TWC, r8
+	mtspr	MD_TWC, r8
+	li	r8, MI_BOOTINIT|0x2	/* Create RPN for address 0 */
+	mtspr	MI_RPN, r8		/* Store TLB entry */
+	mtspr	MD_RPN, r8
+	lis	r8, MI_Kp@h		/* Set the protection mode */
+	mtspr	MI_AP, r8
+	mtspr	MD_AP, r8
+
+	/* Now map the higher 8 Meg into the TLBs.  For this quick hack,
+	 * we can load the instruction and data TLB registers with the
+	 * same values.
+	 */
+	lwz	r9,20(r29)		/* gd->ram_size */
+	addis	r9,r9,-0x80
+
+	mr	r8, r9			/* Higher 8 Meg in SDRAM */
+	ori	r8, r8, MI_EVALID	/* Mark page valid */
+	mtspr	MI_EPN, r8
+	mtspr	MD_EPN, r8
+	li	r8, MI_PS8MEG		/* Set 8M byte page */
+	ori	r8, r8, MI_SVALID	/* Make it valid */
+	mtspr	MI_TWC, r8
+	mtspr	MD_TWC, r8
+	mr	r8, r9
+	ori	r8, r8, MI_BOOTINIT|0x2
+	mtspr	MI_RPN, r8		/* Store TLB entry */
+	mtspr	MD_RPN, r8
+	lis	r8, MI_Kp@h		/* Set the protection mode */
+	mtspr	MI_AP, r8
+	mtspr	MD_AP, r8
+
+	/* Map another 8 MByte at the IMMR to get the processor
+	 * internal registers (among other things).
+	 */
+	mfspr	r9, 638			/* Get current IMMR */
+	andis.	r9, r9, 0xff80		/* Get 8Mbyte boundary */
+
+	mr	r8, r9			/* Create vaddr for TLB */
+	ori	r8, r8, MD_EVALID	/* Mark it valid */
+	mtspr	MD_EPN, r8
+	li	r8, MD_PS8MEG		/* Set 8M byte page */
+	ori	r8, r8, MD_SVALID	/* Make it valid */
+	mtspr	MD_TWC, r8
+	mr	r8, r9			/* Create paddr for TLB */
+	ori	r8, r8, MI_BOOTINIT|0x2 /* Inhibit cache -- Cort */
+	mtspr	MD_RPN, r8
+
+	/* We now have the lower and higher 8 Meg mapped into TLB entries,
+	 * and the caches ready to work.
+	 */
+	mfmsr	r0
+	ori	r0,r0,MSR_DR|MSR_IR
+	mtspr	SRR1,r0
+	mflr	r0
+	mtspr	SRR0,r0
+	SYNC
+	rfi	/* enables MMU */
+
+/*
+ *	void caches_init(void);
+ */
+	.globl	caches_init
+caches_init:
+	sync
+
+	mfspr	r3, IC_CST		/* Clear error bits */
+	mfspr	r3, DC_CST
+
+	lis	r3, IDC_UNALL@h		/* Unlock all */
+	mtspr	IC_CST, r3
+	mtspr	DC_CST, r3
+
+	lis	r3, IDC_INVALL@h	/* Invalidate all */
+	mtspr	IC_CST, r3
+	mtspr	DC_CST, r3
+
+	lis	r3, IDC_ENABLE@h	/* Enable all */
+	mtspr	IC_CST, r3
+	mtspr	DC_CST, r3
+
+	blr
+
+/*
+ *	void flush_dcache_range(unsigned long start, unsigned long stop);
+ */
+	.global flush_dcache_range
+flush_dcache_range:
+	li	r5,CACHE_LINE_SIZE-1
+	andc	r3,r3,r5
+	subf	r4,r3,r4
+	add	r4,r4,r5
+	srwi.	r4,r4,LG_CACHE_LINE_SIZE
+	beqlr
+	mtctr	r4
+
+1:	dcbf	0,r3
+	addi	r3,r3,CACHE_LINE_SIZE
+	bdnz	1b
+	sync				/* wait for dcbf's to get to ram */
+	blr
+
+/*
+ *	void disable_interrupts(void);
+ */
+	.global disable_interrupts
+disable_interrupts:
+	mfmsr	r0
+	rlwinm	r0,r0,0,17,15
+	mtmsr	r0
+	blr