Patchwork [U-Boot,3/3] avr32: Add simple paging support

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Submitter Haavard Skinnemoen
Date Aug. 2, 2010, 12:06 p.m.
Message ID <1280750789-10359-4-git-send-email-haavard.skinnemoen@atmel.com>
Download mbox | patch
Permalink /patch/71804/
State Accepted
Commit 1f36f73fe70560a2bd286a7abc8530fdc93af9ae
Delegated to: Reinhard Meyer
Headers show

Comments

Haavard Skinnemoen - Aug. 2, 2010, 12:06 p.m.
Use the MMU hardware to set up 1:1 mappings between physical and virtual
addresses. This allows us to bypass the cache when accessing the flash
without having to do any physical-to-virtual address mapping in the CFI
driver.

The virtual memory mappings are defined at compile time through a sorted
array of virtual memory range objects. When a TLB miss exception
happens, the exception handler does a binary search through the array
until it finds a matching entry and loads it into the TLB. The u-boot
image itself is covered by a fixed TLB entry which is never replaced.

This makes the 'saveenv' command work again on ATNGW100 and other boards
using the CFI driver, hopefully without breaking any rules.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
---
 arch/avr32/cpu/at32ap700x/Makefile                 |    2 +-
 arch/avr32/cpu/at32ap700x/mmu.c                    |   78 ++++++++++++++++++++
 arch/avr32/cpu/start.S                             |   19 +++--
 arch/avr32/include/asm/arch-at32ap700x/addrspace.h |    5 +-
 arch/avr32/include/asm/arch-at32ap700x/mmu.h       |   66 +++++++++++++++++
 arch/avr32/lib/board.c                             |    4 +
 board/atmel/atngw100/atngw100.c                    |   15 ++++
 board/atmel/atstk1000/atstk1000.c                  |   15 ++++
 board/earthlcd/favr-32-ezkit/favr-32-ezkit.c       |   15 ++++
 board/mimc/mimc200/mimc200.c                       |   20 +++++
 board/miromico/hammerhead/hammerhead.c             |   15 ++++
 include/configs/atngw100.h                         |    3 +
 include/configs/atstk1002.h                        |    3 +
 include/configs/atstk1003.h                        |    3 +
 include/configs/atstk1004.h                        |    3 +
 include/configs/atstk1006.h                        |    3 +
 include/configs/favr-32-ezkit.h                    |    3 +
 include/configs/hammerhead.h                       |    3 +
 include/configs/mimc200.h                          |    3 +
 19 files changed, 267 insertions(+), 11 deletions(-)
 create mode 100644 arch/avr32/cpu/at32ap700x/mmu.c
 create mode 100644 arch/avr32/include/asm/arch-at32ap700x/mmu.h
Andreas Bießmann - Aug. 2, 2010, 2:13 p.m.
Dear Håvard Skinnemoen,

I have tested the simple TLB implementation on our own hardware and it
does work with CFI driver.
Thanks a lot for introducing this, we had to wait so long ...

Am 02.08.2010 14:06, schrieb Haavard Skinnemoen:
> Use the MMU hardware to set up 1:1 mappings between physical and virtual
> addresses. This allows us to bypass the cache when accessing the flash
> without having to do any physical-to-virtual address mapping in the CFI
> driver.
> 
> The virtual memory mappings are defined at compile time through a sorted
> array of virtual memory range objects. When a TLB miss exception
> happens, the exception handler does a binary search through the array
> until it finds a matching entry and loads it into the TLB. The u-boot
> image itself is covered by a fixed TLB entry which is never replaced.
> 
> This makes the 'saveenv' command work again on ATNGW100 and other boards
> using the CFI driver, hopefully without breaking any rules.
> 
> Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Tested-by: Andreas Bießmann <biessmann@corscience.de>
Wolfgang Denk - Aug. 7, 2010, 9:10 p.m.
Dear Haavard Skinnemoen,

In message <1280750789-10359-4-git-send-email-haavard.skinnemoen@atmel.com> you wrote:
> Use the MMU hardware to set up 1:1 mappings between physical and virtual
> addresses. This allows us to bypass the cache when accessing the flash
> without having to do any physical-to-virtual address mapping in the CFI
> driver.
> 
> The virtual memory mappings are defined at compile time through a sorted
> array of virtual memory range objects. When a TLB miss exception
> happens, the exception handler does a binary search through the array
> until it finds a matching entry and loads it into the TLB. The u-boot
> image itself is covered by a fixed TLB entry which is never replaced.
> 
> This makes the 'saveenv' command work again on ATNGW100 and other boards
> using the CFI driver, hopefully without breaking any rules.

Can you please try and rebase this code on top of Heiko's ARM rework
patches, i. e. with cache and relocation support?

See
http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/81825/focus=82142


My intention is that after -rc1 has been released (i. e. when we have
a "next" branch again), I will first apply the new environment code
patches, and then, probably with a week delay or so, Heiko's ARM
rework.  Your stuff will then have to fit on top of this.

Thanks.

Best regards,

Wolfgang Denk

Patch

diff --git a/arch/avr32/cpu/at32ap700x/Makefile b/arch/avr32/cpu/at32ap700x/Makefile
index 46e6ef6..30ea925 100644
--- a/arch/avr32/cpu/at32ap700x/Makefile
+++ b/arch/avr32/cpu/at32ap700x/Makefile
@@ -24,7 +24,7 @@  include $(TOPDIR)/config.mk
 
 LIB	:= $(obj)lib$(SOC).a
 
-COBJS	:= portmux.o clk.o
+COBJS	:= portmux.o clk.o mmu.o
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))
 
diff --git a/arch/avr32/cpu/at32ap700x/mmu.c b/arch/avr32/cpu/at32ap700x/mmu.c
new file mode 100644
index 0000000..c3a1b93
--- /dev/null
+++ b/arch/avr32/cpu/at32ap700x/mmu.c
@@ -0,0 +1,78 @@ 
+#include <common.h>
+#include <asm/arch/mmu.h>
+#include <asm/sysreg.h>
+
+void mmu_init_r(unsigned long dest_addr)
+{
+	uintptr_t	vmr_table_addr;
+
+	/* Round monitor address down to the nearest page boundary */
+	dest_addr &= PAGE_ADDR_MASK;
+
+	/* Initialize TLB entry 0 to cover the monitor, and lock it */
+	sysreg_write(TLBEHI, dest_addr | SYSREG_BIT(TLBEHI_V));
+	sysreg_write(TLBELO, dest_addr | MMU_VMR_CACHE_WRBACK);
+	sysreg_write(MMUCR, SYSREG_BF(DRP, 0) | SYSREG_BF(DLA, 1)
+			| SYSREG_BIT(MMUCR_S) | SYSREG_BIT(M));
+	__builtin_tlbw();
+
+	/*
+	 * Calculate the address of the VM range table in a PC-relative
+	 * manner to make sure we hit the SDRAM and not the flash.
+	 */
+	vmr_table_addr = (uintptr_t)&mmu_vmr_table;
+	sysreg_write(PTBR, vmr_table_addr);
+	printf("VMR table @ 0x%08x\n", vmr_table_addr);
+
+	/* Enable paging */
+	sysreg_write(MMUCR, SYSREG_BF(DRP, 1) | SYSREG_BF(DLA, 1)
+			| SYSREG_BIT(MMUCR_S) | SYSREG_BIT(M) | SYSREG_BIT(E));
+}
+
+int mmu_handle_tlb_miss(void)
+{
+	const struct mmu_vm_range *vmr_table;
+	const struct mmu_vm_range *vmr;
+	unsigned int fault_pgno;
+	int first, last;
+
+	fault_pgno = sysreg_read(TLBEAR) >> PAGE_SHIFT;
+	vmr_table = (const struct mmu_vm_range *)sysreg_read(PTBR);
+
+	/* Do a binary search through the VM ranges */
+	first = 0;
+	last = CONFIG_SYS_NR_VM_REGIONS;
+	while (first < last) {
+		unsigned int start;
+		int middle;
+
+		/* Pick the entry in the middle of the remaining range */
+		middle = (first + last) >> 1;
+		vmr = &vmr_table[middle];
+		start = vmr->virt_pgno;
+
+		/* Do the bisection thing */
+		if (fault_pgno < start) {
+			last = middle;
+		} else if (fault_pgno >= (start + vmr->nr_pages)) {
+			first = middle + 1;
+		} else {
+			/* Got it; let's slam it into the TLB */
+			uint32_t tlbelo;
+
+			tlbelo = vmr->phys & ~PAGE_ADDR_MASK;
+			tlbelo |= fault_pgno << PAGE_SHIFT;
+			sysreg_write(TLBELO, tlbelo);
+			__builtin_tlbw();
+
+			/* Zero means success */
+			return 0;
+		}
+	}
+
+	/*
+	 * Didn't find any matching entries. Return a nonzero value to
+	 * indicate that this should be treated as a fatal exception.
+	 */
+	return -1;
+}
diff --git a/arch/avr32/cpu/start.S b/arch/avr32/cpu/start.S
index d37a46e..c43b684 100644
--- a/arch/avr32/cpu/start.S
+++ b/arch/avr32/cpu/start.S
@@ -81,12 +81,19 @@  _evba:
 	.org	0x44
 	rjmp	unknown_exception	/* DTLB Modified */
 
-	.org	0x50
-	rjmp	unknown_exception	/* ITLB Miss */
-	.org	0x60
-	rjmp	unknown_exception	/* DTLB Miss (read) */
-	.org	0x70
-	rjmp	unknown_exception	/* DTLB Miss (write) */
+	.org	0x50			/* ITLB Miss */
+	pushm   r8-r12,lr
+	rjmp	1f
+	.org	0x60			/* DTLB Miss (read) */
+	pushm   r8-r12,lr
+	rjmp	1f
+	.org	0x70			/* DTLB Miss (write) */
+	pushm   r8-r12,lr
+1:	mov	r12, sp
+	rcall	mmu_handle_tlb_miss
+	popm	r8-r12,lr
+	brne	unknown_exception
+	rete
 
 	.size	_evba, . - _evba
 
diff --git a/arch/avr32/include/asm/arch-at32ap700x/addrspace.h b/arch/avr32/include/asm/arch-at32ap700x/addrspace.h
index 409eee3..4edc1bd 100644
--- a/arch/avr32/include/asm/arch-at32ap700x/addrspace.h
+++ b/arch/avr32/include/asm/arch-at32ap700x/addrspace.h
@@ -75,10 +75,7 @@  static inline void * phys_to_virt(unsigned long address)
 static inline void *
 map_physmem(phys_addr_t paddr, unsigned long len, unsigned long flags)
 {
-	if (flags == MAP_WRBACK)
-		return (void *)P1SEGADDR(paddr);
-	else
-		return (void *)P2SEGADDR(paddr);
+	return (void *)paddr;
 }
 
 #endif /* __ASM_AVR32_ADDRSPACE_H */
diff --git a/arch/avr32/include/asm/arch-at32ap700x/mmu.h b/arch/avr32/include/asm/arch-at32ap700x/mmu.h
new file mode 100644
index 0000000..fcd9a05
--- /dev/null
+++ b/arch/avr32/include/asm/arch-at32ap700x/mmu.h
@@ -0,0 +1,66 @@ 
+/*
+ * In order to deal with the hardcoded u-boot requirement that virtual
+ * addresses are always mapped 1:1 with physical addresses, we implement
+ * a small virtual memory manager so that we can use the MMU hardware in
+ * order to get the caching properties right.
+ *
+ * A few pages (or possibly just one) are locked in the TLB permanently
+ * in order to avoid recursive TLB misses, but most pages are faulted in
+ * on demand.
+ */
+#ifndef __ASM_ARCH_MMU_H
+#define __ASM_ARCH_MMU_H
+
+#include <asm/sysreg.h>
+
+#define PAGE_SHIFT	20
+#define PAGE_SIZE	(1UL << PAGE_SHIFT)
+#define PAGE_ADDR_MASK	(~(PAGE_SIZE - 1))
+
+#define MMU_VMR_CACHE_NONE						\
+	(SYSREG_BF(AP, 3) | SYSREG_BF(SZ, 3) | SYSREG_BIT(TLBELO_D))
+#define MMU_VMR_CACHE_WBUF						\
+	(MMU_VMR_CACHE_NONE | SYSREG_BIT(B))
+#define MMU_VMR_CACHE_WRTHRU						\
+	(MMU_VMR_CACHE_NONE | SYSREG_BIT(TLBELO_C) | SYSREG_BIT(W))
+#define MMU_VMR_CACHE_WRBACK						\
+	(MMU_VMR_CACHE_WBUF | SYSREG_BIT(TLBELO_C))
+
+/*
+ * This structure is used in our "page table". Instead of the usual
+ * x86-inspired radix tree, we let each entry cover an arbitrary-sized
+ * virtual address range and store them in a binary search tree. This is
+ * somewhat slower, but should use significantly less RAM, and we
+ * shouldn't get many TLB misses when using 1 MB pages anyway.
+ *
+ * With 1 MB pages, we need 12 bits to store the page number. In
+ * addition, we stick an Invalid bit in the high bit of virt_pgno (if
+ * set, it cannot possibly match any faulting page), and all the bits
+ * that need to be written to TLBELO in phys_pgno.
+ */
+struct mmu_vm_range {
+	uint16_t	virt_pgno;
+	uint16_t	nr_pages;
+	uint32_t	phys;
+};
+
+/*
+ * An array of mmu_vm_range objects describing all pageable addresses.
+ * The array is sorted by virt_pgno so that the TLB miss exception
+ * handler can do a binary search to find the correct entry.
+ */
+extern struct mmu_vm_range mmu_vmr_table[];
+
+/*
+ * Initialize the MMU. This will set up a fixed TLB entry for the static
+ * u-boot image at dest_addr and enable paging.
+ */
+void mmu_init_r(unsigned long dest_addr);
+
+/*
+ * Handle a TLB miss exception. This function is called directly from
+ * the exception vector table written in assembly.
+ */
+int mmu_handle_tlb_miss(void);
+
+#endif /* __ASM_ARCH_MMU_H */
diff --git a/arch/avr32/lib/board.c b/arch/avr32/lib/board.c
index 917ed6c..6754732 100644
--- a/arch/avr32/lib/board.c
+++ b/arch/avr32/lib/board.c
@@ -33,6 +33,7 @@ 
 
 #include <asm/initcalls.h>
 #include <asm/sections.h>
+#include <asm/arch/mmu.h>
 
 #ifndef CONFIG_IDENT_STRING
 #define CONFIG_IDENT_STRING ""
@@ -264,6 +265,9 @@  void board_init_r(gd_t *new_gd, ulong dest_addr)
 	gd->flags |= GD_FLG_RELOC;
 	gd->reloc_off = dest_addr - CONFIG_SYS_MONITOR_BASE;
 
+	/* Enable the MMU so that we can keep u-boot simple */
+	mmu_init_r(dest_addr);
+
 	board_early_init_r();
 
 	monitor_flash_len = _edata - _text;
diff --git a/board/atmel/atngw100/atngw100.c b/board/atmel/atngw100/atngw100.c
index 004d8da..978f0c8 100644
--- a/board/atmel/atngw100/atngw100.c
+++ b/board/atmel/atngw100/atngw100.c
@@ -26,11 +26,26 @@ 
 #include <asm/arch/clk.h>
 #include <asm/arch/gpio.h>
 #include <asm/arch/hmatrix.h>
+#include <asm/arch/mmu.h>
 #include <asm/arch/portmux.h>
 #include <netdev.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
+struct mmu_vm_range mmu_vmr_table[CONFIG_SYS_NR_VM_REGIONS] = {
+	{
+		.virt_pgno	= CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT,
+		.nr_pages	= CONFIG_SYS_FLASH_SIZE >> PAGE_SHIFT,
+		.phys		= (CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT)
+					| MMU_VMR_CACHE_NONE,
+	}, {
+		.virt_pgno	= CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT,
+		.nr_pages	= EBI_SDRAM_SIZE >> PAGE_SHIFT,
+		.phys		= (CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT)
+					| MMU_VMR_CACHE_WRBACK,
+	},
+};
+
 static const struct sdram_config sdram_config = {
 	.data_bits	= SDRAM_DATA_16BIT,
 	.row_bits	= 13,
diff --git a/board/atmel/atstk1000/atstk1000.c b/board/atmel/atstk1000/atstk1000.c
index c36cb57..9cda020 100644
--- a/board/atmel/atstk1000/atstk1000.c
+++ b/board/atmel/atstk1000/atstk1000.c
@@ -25,11 +25,26 @@ 
 #include <asm/sdram.h>
 #include <asm/arch/clk.h>
 #include <asm/arch/hmatrix.h>
+#include <asm/arch/mmu.h>
 #include <asm/arch/portmux.h>
 #include <netdev.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
+struct mmu_vm_range mmu_vmr_table[CONFIG_SYS_NR_VM_REGIONS] = {
+	{
+		.virt_pgno	= CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT,
+		.nr_pages	= CONFIG_SYS_FLASH_SIZE >> PAGE_SHIFT,
+		.phys		= (CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT)
+					| MMU_VMR_CACHE_NONE,
+	}, {
+		.virt_pgno	= CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT,
+		.nr_pages	= EBI_SDRAM_SIZE >> PAGE_SHIFT,
+		.phys		= (CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT)
+					| MMU_VMR_CACHE_WRBACK,
+	},
+};
+
 static const struct sdram_config sdram_config = {
 #if defined(CONFIG_ATSTK1006)
 	/* Dual MT48LC16M16A2-7E (64 MB) on daughterboard */
diff --git a/board/earthlcd/favr-32-ezkit/favr-32-ezkit.c b/board/earthlcd/favr-32-ezkit/favr-32-ezkit.c
index 8af680f..e1c5653 100644
--- a/board/earthlcd/favr-32-ezkit/favr-32-ezkit.c
+++ b/board/earthlcd/favr-32-ezkit/favr-32-ezkit.c
@@ -24,10 +24,25 @@ 
 #include <asm/sdram.h>
 #include <asm/arch/clk.h>
 #include <asm/arch/hmatrix.h>
+#include <asm/arch/mmu.h>
 #include <asm/arch/portmux.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
+struct mmu_vm_range mmu_vmr_table[CONFIG_SYS_NR_VM_REGIONS] = {
+	{
+		.virt_pgno	= CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT,
+		.nr_pages	= CONFIG_SYS_FLASH_SIZE >> PAGE_SHIFT,
+		.phys		= (CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT)
+					| MMU_VMR_CACHE_NONE,
+	}, {
+		.virt_pgno	= CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT,
+		.nr_pages	= EBI_SDRAM_SIZE >> PAGE_SHIFT,
+		.phys		= (CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT)
+					| MMU_VMR_CACHE_WRBACK,
+	},
+};
+
 static const struct sdram_config sdram_config = {
 	/* MT48LC4M32B2P-6 (16 MB) */
 	.data_bits	= SDRAM_DATA_32BIT,
diff --git a/board/mimc/mimc200/mimc200.c b/board/mimc/mimc200/mimc200.c
index cc0f137..ca7fc23 100644
--- a/board/mimc/mimc200/mimc200.c
+++ b/board/mimc/mimc200/mimc200.c
@@ -27,12 +27,32 @@ 
 #include <asm/arch/clk.h>
 #include <asm/arch/gpio.h>
 #include <asm/arch/hmatrix.h>
+#include <asm/arch/mmu.h>
 #include <asm/arch/portmux.h>
 #include <atmel_lcdc.h>
 #include <lcd.h>
 
 #include "../../../arch/avr32/cpu/hsmc3.h"
 
+struct mmu_vm_range mmu_vmr_table[CONFIG_SYS_NR_VM_REGIONS] = {
+	{
+		.virt_pgno	= CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT,
+		.nr_pages	= CONFIG_SYS_FLASH_SIZE >> PAGE_SHIFT,
+		.phys		= (CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT)
+					| MMU_VMR_CACHE_NONE,
+	}, {
+		.virt_pgno	= EBI_SRAM_CS2_BASE >> PAGE_SHIFT,
+		.nr_pages	= EBI_SRAM_CS2_SIZE >> PAGE_SHIFT,
+		.phys		= (EBI_SRAM_CS2_BASE >> PAGE_SHIFT)
+					| MMU_VMR_CACHE_NONE,
+	}, {
+		.virt_pgno	= CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT,
+		.nr_pages	= EBI_SDRAM_SIZE >> PAGE_SHIFT,
+		.phys		= (CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT)
+					| MMU_VMR_CACHE_WRBACK,
+	},
+};
+
 #if defined(CONFIG_LCD)
 /* 480x272x16 @ 72 Hz */
 vidinfo_t panel_info = {
diff --git a/board/miromico/hammerhead/hammerhead.c b/board/miromico/hammerhead/hammerhead.c
index 8b3e22c..6a6dc30 100644
--- a/board/miromico/hammerhead/hammerhead.c
+++ b/board/miromico/hammerhead/hammerhead.c
@@ -30,10 +30,25 @@ 
 #include <asm/arch/clk.h>
 #include <asm/arch/hmatrix.h>
 #include <asm/arch/memory-map.h>
+#include <asm/arch/mmu.h>
 #include <asm/arch/portmux.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
+struct mmu_vm_range mmu_vmr_table[CONFIG_SYS_NR_VM_REGIONS] = {
+	{
+		.virt_pgno	= CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT,
+		.nr_pages	= CONFIG_SYS_FLASH_SIZE >> PAGE_SHIFT,
+		.phys		= (CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT)
+					| MMU_VMR_CACHE_NONE,
+	}, {
+		.virt_pgno	= CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT,
+		.nr_pages	= EBI_SDRAM_SIZE >> PAGE_SHIFT,
+		.phys		= (CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT)
+					| MMU_VMR_CACHE_WRBACK,
+	},
+};
+
 static const struct sdram_config sdram_config = {
 	.data_bits	= SDRAM_DATA_32BIT,
 	.row_bits	= 13,
diff --git a/include/configs/atngw100.h b/include/configs/atngw100.h
index 4ed5514..83056b6 100644
--- a/include/configs/atngw100.h
+++ b/include/configs/atngw100.h
@@ -49,6 +49,9 @@ 
 #define CONFIG_SYS_CLKDIV_PBA			2
 #define CONFIG_SYS_CLKDIV_PBB			1
 
+/* Reserve VM regions for SDRAM and NOR flash */
+#define CONFIG_SYS_NR_VM_REGIONS		2
+
 /*
  * The PLLOPT register controls the PLL like this:
  *   icp = PLLOPT<2>
diff --git a/include/configs/atstk1002.h b/include/configs/atstk1002.h
index b258f2d..6416d17 100644
--- a/include/configs/atstk1002.h
+++ b/include/configs/atstk1002.h
@@ -73,6 +73,9 @@ 
  */
 #define CONFIG_SYS_CLKDIV_PBB			1
 
+/* Reserve VM regions for SDRAM and NOR flash */
+#define CONFIG_SYS_NR_VM_REGIONS		2
+
 /*
  * The PLLOPT register controls the PLL like this:
  *   icp = PLLOPT<2>
diff --git a/include/configs/atstk1003.h b/include/configs/atstk1003.h
index 2ef2552..a4d9b0b 100644
--- a/include/configs/atstk1003.h
+++ b/include/configs/atstk1003.h
@@ -73,6 +73,9 @@ 
  */
 #define CONFIG_SYS_CLKDIV_PBB			1
 
+/* Reserve VM regions for SDRAM and NOR flash */
+#define CONFIG_SYS_NR_VM_REGIONS		2
+
 /*
  * The PLLOPT register controls the PLL like this:
  *   icp = PLLOPT<2>
diff --git a/include/configs/atstk1004.h b/include/configs/atstk1004.h
index 195be82..06bb5da 100644
--- a/include/configs/atstk1004.h
+++ b/include/configs/atstk1004.h
@@ -73,6 +73,9 @@ 
  */
 #define CONFIG_SYS_CLKDIV_PBB			1
 
+/* Reserve VM regions for SDRAM and NOR flash */
+#define CONFIG_SYS_NR_VM_REGIONS		2
+
 /*
  * The PLLOPT register controls the PLL like this:
  *   icp = PLLOPT<2>
diff --git a/include/configs/atstk1006.h b/include/configs/atstk1006.h
index f93118e..d3cbee6 100644
--- a/include/configs/atstk1006.h
+++ b/include/configs/atstk1006.h
@@ -73,6 +73,9 @@ 
  */
 #define CONFIG_SYS_CLKDIV_PBB			1
 
+/* Reserve VM regions for SDRAM and NOR flash */
+#define CONFIG_SYS_NR_VM_REGIONS		2
+
 /*
  * The PLLOPT register controls the PLL like this:
  *   icp = PLLOPT<2>
diff --git a/include/configs/favr-32-ezkit.h b/include/configs/favr-32-ezkit.h
index 739ff0d..1c381c7 100644
--- a/include/configs/favr-32-ezkit.h
+++ b/include/configs/favr-32-ezkit.h
@@ -70,6 +70,9 @@ 
  */
 #define CONFIG_SYS_CLKDIV_PBB			1
 
+/* Reserve VM regions for SDRAM and NOR flash */
+#define CONFIG_SYS_NR_VM_REGIONS		2
+
 /*
  * The PLLOPT register controls the PLL like this:
  *   icp = PLLOPT<2>
diff --git a/include/configs/hammerhead.h b/include/configs/hammerhead.h
index 0c70af5..8ca04ea 100644
--- a/include/configs/hammerhead.h
+++ b/include/configs/hammerhead.h
@@ -47,6 +47,9 @@ 
 #define CONFIG_SYS_CLKDIV_PBA			2
 #define CONFIG_SYS_CLKDIV_PBB			1
 
+/* Reserve VM regions for SDRAM and NOR flash */
+#define CONFIG_SYS_NR_VM_REGIONS		2
+
 /*
  * The PLLOPT register controls the PLL like this:
  *   icp = PLLOPT<2>
diff --git a/include/configs/mimc200.h b/include/configs/mimc200.h
index 36488b3..6ed9e75 100644
--- a/include/configs/mimc200.h
+++ b/include/configs/mimc200.h
@@ -51,6 +51,9 @@ 
 #define CONFIG_SYS_CLKDIV_PBA			2
 #define CONFIG_SYS_CLKDIV_PBB			1
 
+/* Reserve VM regions for SDRAM, NOR flash and FRAM */
+#define CONFIG_SYS_NR_VM_REGIONS		3
+
 /*
  * The PLLOPT register controls the PLL like this:
  *   icp = PLLOPT<2>