New mechanism to define SRAM/memory map with automatic bounds checking

This patch creates a new mechanism to define the static memory layout
(primarily in SRAM) for a given board, superseding the brittle mass of
Kconfigs that we were using before. The core part is a memlayout.ld file
in the mainboard directory (although boards are expected to just include
the SoC default in most cases), which is the primary linker script for
all stages (though not rmodules for now). It uses preprocessor macros
from <memlayout.h> to form a different valid linker script for all
stages while looking like a declarative, boilerplate-free map of memory
addresses to the programmer. Linker asserts will automatically guarantee
that the defined regions cannot overlap. Stages are defined with a
maximum size that will be enforced by the linker. The file serves to
both define and document the memory layout, so that the documentation
cannot go missing or out of date.

The mechanism is implemented for all boards in the ARM, ARM64 and MIPS
architectures, and should be extended onto all systems using SRAM in the
future. The CAR/XIP environment on x86 has very different requirements
and the layout is generally not as static, so it will stay like it is
and be unaffected by this patch (save for aligning some symbol names for
consistency and sharing the new common ramstage linker script include).

BUG=None
TEST=Booted normally and in recovery mode, checked suspend/resume and
the CBMEM console on Falco, Blaze (both normal and vboot2), Pinky and
Pit. Compiled Ryu, Storm and Urara, manually compared the disassemblies
with ToT and looked for red flags.

Change-Id: Ifd2276417f2036cbe9c056f17e42f051bcd20e81
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: f1e2028e7ebceeb2d71ff366150a37564595e614
Original-Change-Id: I005506add4e8fcdb74db6d5e6cb2d4cb1bd3cda5
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/213370
Reviewed-on: http://review.coreboot.org/9283
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Tauner <stefan.tauner@gmx.at>
Reviewed-by: Aaron Durbin <adurbin@google.com>

49 files changed, 267 insertions, 176 deletions

diff --git a/src/mainboard/cubietech/cubieboard/Makefile.inc b/src/mainboard/cubietech/cubieboard/Makefile.inc
index 9bd017393c..f3a6de237d 100644
--- a/src/mainboard/cubietech/cubieboard/Makefile.inc
+++ b/src/mainboard/cubietech/cubieboard/Makefile.inc
@@ -1,2 +1,6 @@
 bootblock-y += bootblock.c
 romstage-y += romstage.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/cubietech/cubieboard/memlayout.ld b/src/mainboard/cubietech/cubieboard/memlayout.ld
new file mode 100644
index 0000000000..ee3674dab8
--- /dev/null
+++ b/src/mainboard/cubietech/cubieboard/memlayout.ld
@@ -0,0 +1,36 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2013  Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <memlayout.h>
+
+#include <arch/header.ld>
+
+SECTIONS
+{
+	SRAM_START(0x0)
+	/* eGON.BT0: 32 bytes */
+	BOOTBLOCK(0x20, 0x5fa0)
+	STACK(0x6000, 8K)
+	SRAM_END(0x8000)
+
+	DRAM_START(0x40000000)
+	RAMSTAGE(0x40000000, 16M)
+	ROMSTAGE(0x41000000, 108K)
+}
+
diff --git a/src/mainboard/emulation/qemu-armv7/Kconfig b/src/mainboard/emulation/qemu-armv7/Kconfig
index b275e88eed..c0e7095464 100644
--- a/src/mainboard/emulation/qemu-armv7/Kconfig
+++ b/src/mainboard/emulation/qemu-armv7/Kconfig
@@ -49,45 +49,10 @@ config MAINBOARD_VENDOR
 	string
 	default "ARM Ltd."
 
-config SYS_SDRAM_BASE
-	hex "SDRAM base address"
-	default 0x01000000
-
 config DRAM_SIZE_MB
 	int
 	default 1024
 
-# Memory map for qemu vexpress-a9:
-#
-# 0x0000_0000: jump instruction (by qemu)
-# 0x0001_0000: bootblock (entry of kernel / firmware)
-# 0x0002_0000: romstage, assume up to 128KB in size.
-# 0x0007_ff00: stack pointer
-# 0x0010_0000: CBFS header
-# 0x0011_0000: CBFS data
-# 0x0100_0000: reserved for ramstage
-# 0x1000_0000: I/O map address
-#
-config STACK_TOP
-	hex
-	default 0x00100000
-
-config STACK_BOTTOM
-	hex
-	default 0x0007FF00
-
-config BOOTBLOCK_BASE
-	hex
-	default 0x00010000
-
-config ROMSTAGE_BASE
-	hex
-	default 0x00020000
-
-config RAMSTAGE_BASE
-	hex
-	default SYS_SDRAM_BASE
-
 config BOOTBLOCK_ROM_OFFSET
 	hex
 	default 0x0
diff --git a/src/mainboard/emulation/qemu-armv7/Makefile.inc b/src/mainboard/emulation/qemu-armv7/Makefile.inc
index 4119f93285..d5742e1aad 100644
--- a/src/mainboard/emulation/qemu-armv7/Makefile.inc
+++ b/src/mainboard/emulation/qemu-armv7/Makefile.inc
@@ -28,3 +28,7 @@ ramstage-y += timer.c
 bootblock-y += mmio.c
 romstage-y += mmio.c
 ramstage-y += mmio.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/emulation/qemu-armv7/cbmem.c b/src/mainboard/emulation/qemu-armv7/cbmem.c
index 84f88cfa83..af662c039c 100644
--- a/src/mainboard/emulation/qemu-armv7/cbmem.c
+++ b/src/mainboard/emulation/qemu-armv7/cbmem.c
@@ -17,8 +17,9 @@
 
 #include <stddef.h>
 #include <cbmem.h>
+#include <symbols.h>
 
 void *cbmem_top(void)
 {
-	return (void *)CONFIG_SYS_SDRAM_BASE + (CONFIG_DRAM_SIZE_MB << 20);
+	return _dram + (CONFIG_DRAM_SIZE_MB << 20);
 }
diff --git a/src/mainboard/emulation/qemu-armv7/media.c b/src/mainboard/emulation/qemu-armv7/media.c
index 11688817ff..c3760ab033 100644
--- a/src/mainboard/emulation/qemu-armv7/media.c
+++ b/src/mainboard/emulation/qemu-armv7/media.c
@@ -14,6 +14,7 @@
  */
 #include <cbfs.h>
 #include <string.h>
+#include <symbols.h>
 #include <console/console.h>
 
 /* Simple memory-mapped ROM emulation. */
@@ -25,7 +26,7 @@ static int emu_rom_open(struct cbfs_media *media)
 
 static void *emu_rom_map(struct cbfs_media *media, size_t offset, size_t count)
 {
-        return (void*)(offset + CONFIG_BOOTBLOCK_BASE);
+        return (void*)offset;
 }
 
 static void *emu_rom_unmap(struct cbfs_media *media, const void *address)
diff --git a/src/mainboard/emulation/qemu-armv7/memlayout.ld b/src/mainboard/emulation/qemu-armv7/memlayout.ld
new file mode 100644
index 0000000000..14859894e6
--- /dev/null
+++ b/src/mainboard/emulation/qemu-armv7/memlayout.ld
@@ -0,0 +1,47 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2014 Google Inc.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <memlayout.h>
+
+#include <arch/header.ld>
+
+/*
+ * Memory map for qemu vexpress-a9:
+ *
+ * 0x0000_0000: jump instruction (by qemu)
+ * 0x0001_0000: bootblock (entry of kernel / firmware)
+ * 0x0002_0000: romstage, assume up to 128KB in size.
+ * 0x0007_ff00: stack pointer
+ * 0x0010_0000: CBFS header
+ * 0x0011_0000: CBFS data
+ * 0x0100_0000: reserved for ramstage
+ * 0x1000_0000: I/O map address
+ */
+
+SECTIONS
+{
+	/* TODO: does this thing emulate SRAM? */
+
+	BOOTBLOCK(0x10000, 64K)
+	ROMSTAGE(0x20000, 128K)
+	STACK(0x000FC000, 16K)
+
+	DRAM_START(0x01000000)
+	RAMSTAGE(0x01000000, 16M)
+}
diff --git a/src/mainboard/emulation/qemu-riscv/Kconfig b/src/mainboard/emulation/qemu-riscv/Kconfig
index d7d5cc984c..5425ca5cb0 100644
--- a/src/mainboard/emulation/qemu-riscv/Kconfig
+++ b/src/mainboard/emulation/qemu-riscv/Kconfig
@@ -54,18 +54,6 @@ config DRAM_SIZE_MB
 # 0x0011_0000: CBFS data
 # 0x0100_0000: reserved for ramstage
 
-config BOOTBLOCK_BASE
-	hex
-	default 0x00000000
-
-config ROMSTAGE_BASE
-	hex
-	default 0x00020000
-
-config RAMSTAGE_BASE
-	hex
-	default 0x100000
-
 config BOOTBLOCK_ROM_OFFSET
 	hex
 	default 0x0
@@ -82,16 +70,4 @@ config RAMTOP
 	hex
 	default 0x1000000
 
-config STACK_TOP
-	hex
-	default 0x0007ff00
-
-config STACK_BOTTOM
-	hex
-	default 0x00040000
-
-config STACK_SIZE
-	hex
-	default 0x0003ff00
-
 endif #  BOARD_EMULATION_QEMU_UCB_RISCV
diff --git a/src/mainboard/emulation/qemu-riscv/Makefile.inc b/src/mainboard/emulation/qemu-riscv/Makefile.inc
index bc01d2f6cf..e60e0c1051 100644
--- a/src/mainboard/emulation/qemu-riscv/Makefile.inc
+++ b/src/mainboard/emulation/qemu-riscv/Makefile.inc
@@ -17,3 +17,7 @@ bootblock-y += uart.c
 romstage-y += romstage.c
 romstage-y += uart.c
 ramstage-y += uart.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/emulation/qemu-riscv/memlayout.ld b/src/mainboard/emulation/qemu-riscv/memlayout.ld
new file mode 100644
index 0000000000..082ac8a2cd
--- /dev/null
+++ b/src/mainboard/emulation/qemu-riscv/memlayout.ld
@@ -0,0 +1,33 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2014 Google Inc.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <memlayout.h>
+
+#include <arch/header.ld>
+
+SECTIONS
+{
+	DRAM_START(0x0)
+	BOOTBLOCK(0x0, 64K)
+	ROMSTAGE(0x20000, 128K)
+	STACK(0x40000, 0x3ff00)
+	PRERAM_CBMEM_CONSOLE(0x80000, 8K)
+	RAMSTAGE(0x100000, 16M)
+}
+
diff --git a/src/mainboard/google/daisy/Makefile.inc b/src/mainboard/google/daisy/Makefile.inc
index df9b797367..1f041abc9e 100644
--- a/src/mainboard/google/daisy/Makefile.inc
+++ b/src/mainboard/google/daisy/Makefile.inc
@@ -26,3 +26,7 @@ romstage-y += chromeos.c
 
 ramstage-y += mainboard.c
 ramstage-y += chromeos.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/daisy/mainboard.c b/src/mainboard/google/daisy/mainboard.c
index 5840e51049..138e498de8 100644
--- a/src/mainboard/google/daisy/mainboard.c
+++ b/src/mainboard/google/daisy/mainboard.c
@@ -36,20 +36,17 @@
 #include <soc/samsung/exynos5250/dp.h>
 #include <soc/samsung/exynos5250/periph.h>
 #include <soc/samsung/exynos5250/usb.h>
+#include <symbols.h>
 
 #include "exynos5250.h"
 
 #define MMC0_GPIO_PIN	(58)
 
 /* convenient shorthand (in MB) */
-#define DRAM_START	(CONFIG_SYS_SDRAM_BASE >> 20)
+#define DRAM_START	((uintptr_t)_dram/MiB)
 #define DRAM_SIZE	CONFIG_DRAM_SIZE_MB
 #define DRAM_END	(DRAM_START + DRAM_SIZE)	/* plus one... */
 
-/* Arbitrary range of DMA memory for depthcharge's drivers */
-#define DMA_START	(0x77300000)
-#define DMA_SIZE	(0x00100000)
-
 static struct edid edid = {
 	.ha = 1366,
 	.va = 768,
@@ -333,7 +330,8 @@ static void mainboard_enable(device_t dev)
 	mmu_init();
 	mmu_config_range(0, DRAM_START, DCACHE_OFF);
 	mmu_config_range(DRAM_START, DRAM_SIZE, DCACHE_WRITEBACK);
-	mmu_config_range(DMA_START >> 20, DMA_SIZE >> 20, DCACHE_OFF);
+	mmu_config_range((uintptr_t)_dma_coherent/MiB,
+			 _dma_coherent_size/MiB, DCACHE_OFF);
 	mmu_config_range(DRAM_END, 4096 - DRAM_END, DCACHE_OFF);
 	dcache_mmu_enable();
 
@@ -359,6 +357,6 @@ void lb_board(struct lb_header *header)
 	dma = (struct lb_range *)lb_new_record(header);
 	dma->tag = LB_TAB_DMA;
 	dma->size = sizeof(*dma);
-	dma->range_start = (intptr_t)DMA_START;
-	dma->range_size = DMA_SIZE;
+	dma->range_start = (uintptr_t)_dma_coherent;
+	dma->range_size = _dma_coherent_size;
 }
diff --git a/src/mainboard/google/daisy/memlayout.ld b/src/mainboard/google/daisy/memlayout.ld
new file mode 100644
index 0000000000..72c018edd2
--- /dev/null
+++ b/src/mainboard/google/daisy/memlayout.ld
@@ -0,0 +1 @@
+#include <soc/samsung/exynos5250/memlayout.ld>
diff --git a/src/mainboard/google/nyan/Kconfig b/src/mainboard/google/nyan/Kconfig
index 864e577c3d..082985d211 100644
--- a/src/mainboard/google/nyan/Kconfig
+++ b/src/mainboard/google/nyan/Kconfig
@@ -42,14 +42,6 @@ config MAINBOARD_PART_NUMBER
 	string
 	default "Nyan"
 
-config DRAM_DMA_START
-	hex
-	default 0x90000000
-
-config DRAM_DMA_SIZE
-	hex
-	default 0x00200000
-
 choice
 	prompt "BCT boot media"
 	default NYAN_BCT_CFG_SPI
diff --git a/src/mainboard/google/nyan/Makefile.inc b/src/mainboard/google/nyan/Makefile.inc
index 7ac11e8a33..6506abaf6e 100644
--- a/src/mainboard/google/nyan/Makefile.inc
+++ b/src/mainboard/google/nyan/Makefile.inc
@@ -42,3 +42,7 @@ ramstage-y += reset.c
 ramstage-y += boardid.c
 ramstage-y += mainboard.c
 ramstage-$(CONFIG_CHROMEOS) += chromeos.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/nyan/mainboard.c b/src/mainboard/google/nyan/mainboard.c
index b534ea908d..e52db83d18 100644
--- a/src/mainboard/google/nyan/mainboard.c
+++ b/src/mainboard/google/nyan/mainboard.c
@@ -30,6 +30,7 @@
 #include <soc/nvidia/tegra124/pmc.h>
 #include <soc/nvidia/tegra124/spi.h>
 #include <soc/nvidia/tegra/usb.h>
+#include <symbols.h>
 #include <vendorcode/google/chromeos/chromeos.h>
 
 static struct clk_rst_ctlr *clk_rst = (void *)TEGRA_CLK_RST_BASE;
@@ -268,6 +269,6 @@ void lb_board(struct lb_header *header)
 	dma = (struct lb_range *)lb_new_record(header);
 	dma->tag = LB_TAB_DMA;
 	dma->size = sizeof(*dma);
-	dma->range_start = CONFIG_DRAM_DMA_START;
-	dma->range_size = CONFIG_DRAM_DMA_SIZE;
+	dma->range_start = (uintptr_t)_dma_coherent;
+	dma->range_size = _dma_coherent_size;
 }
diff --git a/src/mainboard/google/nyan/memlayout.ld b/src/mainboard/google/nyan/memlayout.ld
new file mode 100644
index 0000000000..33ce6446ad
--- /dev/null
+++ b/src/mainboard/google/nyan/memlayout.ld
@@ -0,0 +1 @@
+#include <soc/nvidia/tegra124/memlayout.ld>
diff --git a/src/mainboard/google/nyan/romstage.c b/src/mainboard/google/nyan/romstage.c
index 1ff500b5d3..f2077bbb27 100644
--- a/src/mainboard/google/nyan/romstage.c
+++ b/src/mainboard/google/nyan/romstage.c
@@ -39,6 +39,7 @@
 #include <soc/addressmap.h>
 #include <soc/clock.h>
 #include <soc/display.h>
+#include <symbols.h>
 #include <timestamp.h>
 
 static void __attribute__((noinline)) romstage(void)
@@ -52,24 +53,25 @@ static void __attribute__((noinline)) romstage(void)
 	sdram_init(get_sdram_config());
 
 	/* used for MMU and CBMEM setup, in MB */
-	u32 dram_start = (CONFIG_SYS_SDRAM_BASE >> 20);
-	u32 dram_end = sdram_max_addressable_mb();	/* plus one... */
-	u32 dram_size = dram_end - dram_start;
+	u32 dram_start_mb = (uintptr_t)_dram/MiB;
+	u32 dram_end_mb = sdram_max_addressable_mb();
+	u32 dram_size_mb = dram_end_mb - dram_start_mb;
 
 	configure_l2_cache();
 	mmu_init();
 	/* Device memory below DRAM is uncached. */
-	mmu_config_range(0, dram_start, DCACHE_OFF);
-	/* SRAM is cached. Round the size up to 2MB, the LPAE page size. */
-	mmu_config_range(0x40000000 >> 20, 2, DCACHE_WRITEBACK);
+	mmu_config_range(0, dram_start_mb, DCACHE_OFF);
+	/* SRAM is cached. MMU code will round size up to page size. */
+	mmu_config_range((uintptr_t)_sram/MiB, div_round_up(_sram_size, MiB),
+			 DCACHE_WRITEBACK);
 	/* DRAM is cached. */
-	mmu_config_range(dram_start, dram_size, DCACHE_WRITEBACK);
+	mmu_config_range(dram_start_mb, dram_size_mb, DCACHE_WRITEBACK);
 	/* A window for DMA is uncached. */
-	mmu_config_range(CONFIG_DRAM_DMA_START >> 20,
-			 CONFIG_DRAM_DMA_SIZE >> 20, DCACHE_OFF);
+	mmu_config_range((uintptr_t)_dma_coherent/MiB,
+			 _dma_coherent_size/MiB, DCACHE_OFF);
 	/* The space above DRAM is uncached. */
-	if (dram_end < 4096)
-		mmu_config_range(dram_end, 4096 - dram_end, DCACHE_OFF);
+	if (dram_end_mb < 4096)
+		mmu_config_range(dram_end_mb, 4096 - dram_end_mb, DCACHE_OFF);
 	mmu_disable_range(0, 1);
 	dcache_mmu_enable();
 
diff --git a/src/mainboard/google/nyan_big/Kconfig b/src/mainboard/google/nyan_big/Kconfig
index 2968b0142e..7334472e41 100644
--- a/src/mainboard/google/nyan_big/Kconfig
+++ b/src/mainboard/google/nyan_big/Kconfig
@@ -44,14 +44,6 @@ config MAINBOARD_PART_NUMBER
 	string
 	default "Nyan Big"
 
-config DRAM_DMA_START
-	hex
-	default 0x90000000
-
-config DRAM_DMA_SIZE
-	hex
-	default 0x00200000
-
 choice
 	prompt "BCT boot media"
 	default NYAN_BIG_BCT_CFG_SPI
diff --git a/src/mainboard/google/nyan_big/Makefile.inc b/src/mainboard/google/nyan_big/Makefile.inc
index 8ca495ce55..fddb44e0e1 100644
--- a/src/mainboard/google/nyan_big/Makefile.inc
+++ b/src/mainboard/google/nyan_big/Makefile.inc
@@ -41,3 +41,7 @@ ramstage-y += reset.c
 ramstage-y += boardid.c
 ramstage-y += mainboard.c
 ramstage-$(CONFIG_CHROMEOS) += chromeos.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/nyan_big/mainboard.c b/src/mainboard/google/nyan_big/mainboard.c
index 86d9fe3b37..05f6faeef1 100644
--- a/src/mainboard/google/nyan_big/mainboard.c
+++ b/src/mainboard/google/nyan_big/mainboard.c
@@ -30,6 +30,7 @@
 #include <soc/nvidia/tegra124/pmc.h>
 #include <soc/nvidia/tegra124/spi.h>
 #include <soc/nvidia/tegra/usb.h>
+#include <symbols.h>
 #include <vendorcode/google/chromeos/chromeos.h>
 
 static struct clk_rst_ctlr *clk_rst = (void *)TEGRA_CLK_RST_BASE;
@@ -266,6 +267,6 @@ void lb_board(struct lb_header *header)
 	dma = (struct lb_range *)lb_new_record(header);
 	dma->tag = LB_TAB_DMA;
 	dma->size = sizeof(*dma);
-	dma->range_start = CONFIG_DRAM_DMA_START;
-	dma->range_size = CONFIG_DRAM_DMA_SIZE;
+	dma->range_start = (uintptr_t)_dma_coherent;
+	dma->range_size = _dma_coherent_size;
 }
diff --git a/src/mainboard/google/nyan_big/memlayout.ld b/src/mainboard/google/nyan_big/memlayout.ld
new file mode 100644
index 0000000000..33ce6446ad
--- /dev/null
+++ b/src/mainboard/google/nyan_big/memlayout.ld
@@ -0,0 +1 @@
+#include <soc/nvidia/tegra124/memlayout.ld>
diff --git a/src/mainboard/google/nyan_big/romstage.c b/src/mainboard/google/nyan_big/romstage.c
index 1ff500b5d3..f2077bbb27 100644
--- a/src/mainboard/google/nyan_big/romstage.c
+++ b/src/mainboard/google/nyan_big/romstage.c
@@ -39,6 +39,7 @@
 #include <soc/addressmap.h>
 #include <soc/clock.h>
 #include <soc/display.h>
+#include <symbols.h>
 #include <timestamp.h>
 
 static void __attribute__((noinline)) romstage(void)
@@ -52,24 +53,25 @@ static void __attribute__((noinline)) romstage(void)
 	sdram_init(get_sdram_config());
 
 	/* used for MMU and CBMEM setup, in MB */
-	u32 dram_start = (CONFIG_SYS_SDRAM_BASE >> 20);
-	u32 dram_end = sdram_max_addressable_mb();	/* plus one... */
-	u32 dram_size = dram_end - dram_start;
+	u32 dram_start_mb = (uintptr_t)_dram/MiB;
+	u32 dram_end_mb = sdram_max_addressable_mb();
+	u32 dram_size_mb = dram_end_mb - dram_start_mb;
 
 	configure_l2_cache();
 	mmu_init();
 	/* Device memory below DRAM is uncached. */
-	mmu_config_range(0, dram_start, DCACHE_OFF);
-	/* SRAM is cached. Round the size up to 2MB, the LPAE page size. */
-	mmu_config_range(0x40000000 >> 20, 2, DCACHE_WRITEBACK);
+	mmu_config_range(0, dram_start_mb, DCACHE_OFF);
+	/* SRAM is cached. MMU code will round size up to page size. */
+	mmu_config_range((uintptr_t)_sram/MiB, div_round_up(_sram_size, MiB),
+			 DCACHE_WRITEBACK);
 	/* DRAM is cached. */
-	mmu_config_range(dram_start, dram_size, DCACHE_WRITEBACK);
+	mmu_config_range(dram_start_mb, dram_size_mb, DCACHE_WRITEBACK);
 	/* A window for DMA is uncached. */
-	mmu_config_range(CONFIG_DRAM_DMA_START >> 20,
-			 CONFIG_DRAM_DMA_SIZE >> 20, DCACHE_OFF);
+	mmu_config_range((uintptr_t)_dma_coherent/MiB,
+			 _dma_coherent_size/MiB, DCACHE_OFF);
 	/* The space above DRAM is uncached. */
-	if (dram_end < 4096)
-		mmu_config_range(dram_end, 4096 - dram_end, DCACHE_OFF);
+	if (dram_end_mb < 4096)
+		mmu_config_range(dram_end_mb, 4096 - dram_end_mb, DCACHE_OFF);
 	mmu_disable_range(0, 1);
 	dcache_mmu_enable();
 
diff --git a/src/mainboard/google/nyan_blaze/Kconfig b/src/mainboard/google/nyan_blaze/Kconfig
index 5938e7ee1c..34959199b3 100644
--- a/src/mainboard/google/nyan_blaze/Kconfig
+++ b/src/mainboard/google/nyan_blaze/Kconfig
@@ -45,14 +45,6 @@ config MAINBOARD_PART_NUMBER
 	string
 	default "Nyan Blaze"
 
-config DRAM_DMA_START
-	hex
-	default 0x90000000
-
-config DRAM_DMA_SIZE
-	hex
-	default 0x00200000
-
 choice
 	prompt "BCT boot media"
 	default NYAN_BLAZE_BCT_CFG_SPI
diff --git a/src/mainboard/google/nyan_blaze/Makefile.inc b/src/mainboard/google/nyan_blaze/Makefile.inc
index dc998d1c2d..343040994c 100644
--- a/src/mainboard/google/nyan_blaze/Makefile.inc
+++ b/src/mainboard/google/nyan_blaze/Makefile.inc
@@ -45,3 +45,8 @@ ramstage-y += reset.c
 ramstage-y += boardid.c
 ramstage-y += mainboard.c
 ramstage-$(CONFIG_CHROMEOS) += chromeos.c
+
+bootblock-y += memlayout.ld
+verstage-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/nyan_blaze/mainboard.c b/src/mainboard/google/nyan_blaze/mainboard.c
index ccbaf63f94..5f1cb49ceb 100644
--- a/src/mainboard/google/nyan_blaze/mainboard.c
+++ b/src/mainboard/google/nyan_blaze/mainboard.c
@@ -30,6 +30,7 @@
 #include <soc/nvidia/tegra124/pmc.h>
 #include <soc/nvidia/tegra124/spi.h>
 #include <soc/nvidia/tegra/usb.h>
+#include <symbols.h>
 #include <vendorcode/google/chromeos/chromeos.h>
 
 static struct clk_rst_ctlr *clk_rst = (void *)TEGRA_CLK_RST_BASE;
@@ -266,6 +267,6 @@ void lb_board(struct lb_header *header)
 	dma = (struct lb_range *)lb_new_record(header);
 	dma->tag = LB_TAB_DMA;
 	dma->size = sizeof(*dma);
-	dma->range_start = CONFIG_DRAM_DMA_START;
-	dma->range_size = CONFIG_DRAM_DMA_SIZE;
+	dma->range_start = (uintptr_t)_dma_coherent;
+	dma->range_size = _dma_coherent_size;
 }
diff --git a/src/mainboard/google/nyan_blaze/memlayout.ld b/src/mainboard/google/nyan_blaze/memlayout.ld
new file mode 100644
index 0000000000..33ce6446ad
--- /dev/null
+++ b/src/mainboard/google/nyan_blaze/memlayout.ld
@@ -0,0 +1 @@
+#include <soc/nvidia/tegra124/memlayout.ld>
diff --git a/src/mainboard/google/nyan_blaze/romstage.c b/src/mainboard/google/nyan_blaze/romstage.c
index fca705df03..fb1b9e2b77 100644
--- a/src/mainboard/google/nyan_blaze/romstage.c
+++ b/src/mainboard/google/nyan_blaze/romstage.c
@@ -39,6 +39,7 @@
 #include <soc/addressmap.h>
 #include <soc/clock.h>
 #include <soc/display.h>
+#include <symbols.h>
 #include <timestamp.h>
 
 static void __attribute__((noinline)) romstage(void)
@@ -52,29 +53,30 @@ static void __attribute__((noinline)) romstage(void)
 	sdram_init(get_sdram_config());
 
 	/* used for MMU and CBMEM setup, in MB */
-	u32 dram_start = (CONFIG_SYS_SDRAM_BASE >> 20);
-	u32 dram_end = sdram_max_addressable_mb();	/* plus one... */
-	u32 dram_size = dram_end - dram_start;
+	u32 dram_start_mb = (uintptr_t)_dram/MiB;
+	u32 dram_end_mb = sdram_max_addressable_mb();
+	u32 dram_size_mb = dram_end_mb - dram_start_mb;
 
 #if !CONFIG_VBOOT2_VERIFY_FIRMWARE
 	configure_l2_cache();
 	mmu_init();
 	/* Device memory below DRAM is uncached. */
-	mmu_config_range(0, dram_start, DCACHE_OFF);
-	/* SRAM is cached. Round the size up to 2MB, the LPAE page size. */
-	mmu_config_range(0x40000000 >> 20, 2, DCACHE_WRITEBACK);
+	mmu_config_range(0, dram_start_mb, DCACHE_OFF);
+	/* SRAM is cached. MMU code will round size up to page size. */
+	mmu_config_range((uintptr_t)_sram/MiB, div_round_up(_sram_size, MiB),
+			 DCACHE_WRITEBACK);
 	/* The space above DRAM is uncached. */
-	if (dram_end < 4096)
-		mmu_config_range(dram_end, 4096 - dram_end, DCACHE_OFF);
+	if (dram_end_mb < 4096)
+		mmu_config_range(dram_end_mb, 4096 - dram_end_mb, DCACHE_OFF);
 	mmu_disable_range(0, 1);
 	dcache_mmu_enable();
 #endif
 
 	/* DRAM is cached. */
-	mmu_config_range(dram_start, dram_size, DCACHE_WRITEBACK);
+	mmu_config_range(dram_start_mb, dram_size_mb, DCACHE_WRITEBACK);
 	/* A window for DMA is uncached. */
-	mmu_config_range(CONFIG_DRAM_DMA_START >> 20,
-			 CONFIG_DRAM_DMA_SIZE >> 20, DCACHE_OFF);
+	mmu_config_range((uintptr_t)_dma_coherent/MiB,
+			 _dma_coherent_size/MiB, DCACHE_OFF);
 
 	/*
 	 * A watchdog reset only resets part of the system so it ends up in
diff --git a/src/mainboard/google/peach_pit/Makefile.inc b/src/mainboard/google/peach_pit/Makefile.inc
index df9b797367..1f041abc9e 100644
--- a/src/mainboard/google/peach_pit/Makefile.inc
+++ b/src/mainboard/google/peach_pit/Makefile.inc
@@ -26,3 +26,7 @@ romstage-y += chromeos.c
 
 ramstage-y += mainboard.c
 ramstage-y += chromeos.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/peach_pit/mainboard.c b/src/mainboard/google/peach_pit/mainboard.c
index 1a15bd2347..b6f49e2942 100644
--- a/src/mainboard/google/peach_pit/mainboard.c
+++ b/src/mainboard/google/peach_pit/mainboard.c
@@ -40,15 +40,12 @@
 #include <drivers/parade/ps8625/ps8625.h>
 #include <ec/google/chromeec/ec.h>
 #include <stdlib.h>
+#include <symbols.h>
 
 /* convenient shorthand (in MB) */
-#define DRAM_START	(CONFIG_SYS_SDRAM_BASE >> 20)
+#define DRAM_START	((uintptr_t)_dram/MiB)
 #define DRAM_SIZE	CONFIG_DRAM_SIZE_MB
 
-/* Arbitrary range of DMA memory for depthcharge's drivers */
-#define DMA_START	(0x77300000)
-#define DMA_SIZE	(0x00100000)
-
 static struct edid edid = {
 	.ha = 1366,
 	.va = 768,
@@ -469,7 +466,8 @@ static void mainboard_enable(device_t dev)
 
 	/* set up caching for the DRAM */
 	mmu_config_range(DRAM_START, DRAM_SIZE, DCACHE_WRITEBACK);
-	mmu_config_range(DMA_START >> 20, DMA_SIZE >> 20, DCACHE_OFF);
+	mmu_config_range((uintptr_t)_dma_coherent/MiB,
+			 _dma_coherent_size/MiB, DCACHE_OFF);
 
 	const unsigned epll_hz = 192000000;
 	const unsigned sample_rate = 48000;
@@ -493,6 +491,6 @@ void lb_board(struct lb_header *header)
 	dma = (struct lb_range *)lb_new_record(header);
 	dma->tag = LB_TAB_DMA;
 	dma->size = sizeof(*dma);
-	dma->range_start = (intptr_t)DMA_START;
-	dma->range_size = DMA_SIZE;
+	dma->range_start = (uintptr_t)_dma_coherent;
+	dma->range_size = _dma_coherent_size;
 }
diff --git a/src/mainboard/google/peach_pit/memlayout.ld b/src/mainboard/google/peach_pit/memlayout.ld
new file mode 100644
index 0000000000..565ba89194
--- /dev/null
+++ b/src/mainboard/google/peach_pit/memlayout.ld
@@ -0,0 +1 @@
+#include <soc/samsung/exynos5420/memlayout.ld>
diff --git a/src/mainboard/google/rush/Makefile.inc b/src/mainboard/google/rush/Makefile.inc
index 2a1ce99527..e41745f1a1 100644
--- a/src/mainboard/google/rush/Makefile.inc
+++ b/src/mainboard/google/rush/Makefile.inc
@@ -40,3 +40,7 @@ ramstage-y += boardid.c
 ramstage-y += mainboard.c
 ramstage-y += reset.c
 ramstage-$(CONFIG_CHROMEOS) += chromeos.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/rush/memlayout.ld b/src/mainboard/google/rush/memlayout.ld
new file mode 100644
index 0000000000..b9def51e74
--- /dev/null
+++ b/src/mainboard/google/rush/memlayout.ld
@@ -0,0 +1 @@
+#include <soc/nvidia/tegra132/memlayout.ld>
diff --git a/src/mainboard/google/rush_ryu/Makefile.inc b/src/mainboard/google/rush_ryu/Makefile.inc
index 2fe12a4ea1..67a3facaba 100644
--- a/src/mainboard/google/rush_ryu/Makefile.inc
+++ b/src/mainboard/google/rush_ryu/Makefile.inc
@@ -41,3 +41,7 @@ ramstage-y += boardid.c
 ramstage-y += mainboard.c
 ramstage-y += reset.c
 ramstage-y += chromeos.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/rush_ryu/memlayout.ld b/src/mainboard/google/rush_ryu/memlayout.ld
new file mode 100644
index 0000000000..b9def51e74
--- /dev/null
+++ b/src/mainboard/google/rush_ryu/memlayout.ld
@@ -0,0 +1 @@
+#include <soc/nvidia/tegra132/memlayout.ld>
diff --git a/src/mainboard/google/storm/Kconfig b/src/mainboard/google/storm/Kconfig
index b0c064c919..3e1e0168bb 100644
--- a/src/mainboard/google/storm/Kconfig
+++ b/src/mainboard/google/storm/Kconfig
@@ -48,12 +48,4 @@ config DRAM_SIZE_MB
 	default 512 if BOARD_VARIANT_AP148
 	default 1024
 
-config DRAM_DMA_START
-	hex
-	default 0x5a000000
-
-config DRAM_DMA_SIZE
-	hex
-	default 0x00200000
-
 endif # BOARD_GOOGLE_STORM
diff --git a/src/mainboard/google/storm/Makefile.inc b/src/mainboard/google/storm/Makefile.inc
index 907638a3ef..6ee0841dc3 100644
--- a/src/mainboard/google/storm/Makefile.inc
+++ b/src/mainboard/google/storm/Makefile.inc
@@ -25,3 +25,7 @@ romstage-y += cdp.c
 ramstage-y += boardid.c
 ramstage-y += cdp.c
 ramstage-y += mainboard.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/storm/mainboard.c b/src/mainboard/google/storm/mainboard.c
index 3da6f905b2..478e2a8b8d 100644
--- a/src/mainboard/google/storm/mainboard.c
+++ b/src/mainboard/google/storm/mainboard.c
@@ -25,19 +25,20 @@
 #include <device/device.h>
 #include <gpiolib.h>
 #include <string.h>
+#include <symbols.h>
 
 #include <soc/qualcomm/ipq806x/include/clock.h>
 #include <soc/qualcomm/ipq806x/include/gpio.h>
 #include <soc/qualcomm/ipq806x/include/usb.h>
 
 /* convenient shorthand (in MB) */
-#define DRAM_START           (CONFIG_SYS_SDRAM_BASE / MiB)
+#define DRAM_START           ((uintptr_t)_dram / MiB)
 #define DRAM_SIZE            (CONFIG_DRAM_SIZE_MB)
 #define DRAM_END             (DRAM_START + DRAM_SIZE)
 
 /* DMA memory for drivers */
-#define DMA_START            (CONFIG_DRAM_DMA_START / MiB)
-#define DMA_SIZE             (CONFIG_DRAM_DMA_SIZE / MiB)
+#define DMA_START            ((uintptr_t)_dma_coherent / MiB)
+#define DMA_SIZE             (_dma_coherent_size / MiB)
 
 #define USB_ENABLE_GPIO		51
 
@@ -134,8 +135,8 @@ void lb_board(struct lb_header *header)
 	dma = (struct lb_range *)lb_new_record(header);
 	dma->tag = LB_TAB_DMA;
 	dma->size = sizeof(*dma);
-	dma->range_start = CONFIG_DRAM_DMA_START;
-	dma->range_size = CONFIG_DRAM_DMA_SIZE;
+	dma->range_start = (uintptr_t)_dma_coherent;
+	dma->range_size = _dma_coherent_size;
 }
 
 static int read_gpio(gpio_t gpio_num)
diff --git a/src/mainboard/google/storm/memlayout.ld b/src/mainboard/google/storm/memlayout.ld
new file mode 100644
index 0000000000..1735835321
--- /dev/null
+++ b/src/mainboard/google/storm/memlayout.ld
@@ -0,0 +1 @@
+#include <soc/qualcomm/ipq806x/memlayout.ld>
diff --git a/src/mainboard/google/urara/Kconfig b/src/mainboard/google/urara/Kconfig
index bde26d6524..a9363f969e 100644
--- a/src/mainboard/google/urara/Kconfig
+++ b/src/mainboard/google/urara/Kconfig
@@ -38,10 +38,6 @@ config MAINBOARD_PART_NUMBER
 	string
 	default "ImgTec Pistachio Virtual Platform"
 
-config SYS_SDRAM_BASE
-	hex "SDRAM base address"
-	default 0x80000000
-
 config DRAM_SIZE_MB
 	int
 	default 256
diff --git a/src/mainboard/google/urara/Makefile.inc b/src/mainboard/google/urara/Makefile.inc
index 4ce6398a2b..5a9dc0216f 100644
--- a/src/mainboard/google/urara/Makefile.inc
+++ b/src/mainboard/google/urara/Makefile.inc
@@ -21,3 +21,6 @@
 
 ramstage-y += mainboard.c
 
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/urara/memlayout.ld b/src/mainboard/google/urara/memlayout.ld
new file mode 100644
index 0000000000..ab0b4dd8ff
--- /dev/null
+++ b/src/mainboard/google/urara/memlayout.ld
@@ -0,0 +1 @@
+#include <soc/imgtec/pistachio/memlayout.ld>
diff --git a/src/mainboard/google/veyron_pinky/Kconfig b/src/mainboard/google/veyron_pinky/Kconfig
index 97a009730a..7c4f084a99 100644
--- a/src/mainboard/google/veyron_pinky/Kconfig
+++ b/src/mainboard/google/veyron_pinky/Kconfig
@@ -61,14 +61,6 @@ config BOOT_MEDIA_SPI_BUS
         int
         default 2
 
-config DRAM_DMA_START
-	hex
-	default 0x10000000
-
-config DRAM_DMA_SIZE
-	hex
-	default 0x00200000
-
 config DRAM_SIZE_MB
 	int
 	default 2048
diff --git a/src/mainboard/google/veyron_pinky/Makefile.inc b/src/mainboard/google/veyron_pinky/Makefile.inc
index c33cfa3166..0cc89d0222 100644
--- a/src/mainboard/google/veyron_pinky/Makefile.inc
+++ b/src/mainboard/google/veyron_pinky/Makefile.inc
@@ -35,3 +35,8 @@ ramstage-y += boardid.c
 ramstage-y += chromeos.c
 ramstage-y += mainboard.c
 ramstage-y += reset.c
+
+bootblock-y += memlayout.ld
+verstage-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/veyron_pinky/mainboard.c b/src/mainboard/google/veyron_pinky/mainboard.c
index 232010ddd9..19d66757ba 100644
--- a/src/mainboard/google/veyron_pinky/mainboard.c
+++ b/src/mainboard/google/veyron_pinky/mainboard.c
@@ -22,6 +22,7 @@
 #include <arch/cache.h>
 #include <delay.h>
 #include <edid.h>
+#include <symbols.h>
 #include <vbe.h>
 #include <boot/coreboot_tables.h>
 #include <device/i2c.h>
@@ -153,6 +154,6 @@ void lb_board(struct lb_header *header)
 	dma = (struct lb_range *)lb_new_record(header);
 	dma->tag = LB_TAB_DMA;
 	dma->size = sizeof(*dma);
-	dma->range_start = CONFIG_DRAM_DMA_START;
-	dma->range_size = CONFIG_DRAM_DMA_SIZE;
+	dma->range_start = (uintptr_t)_dma_coherent;
+	dma->range_size = _dma_coherent_size;
 }
diff --git a/src/mainboard/google/veyron_pinky/memlayout.ld b/src/mainboard/google/veyron_pinky/memlayout.ld
new file mode 100644
index 0000000000..a8b7465c5e
--- /dev/null
+++ b/src/mainboard/google/veyron_pinky/memlayout.ld
@@ -0,0 +1 @@
+#include <soc/rockchip/rk3288/memlayout.ld>
diff --git a/src/mainboard/google/veyron_pinky/romstage.c b/src/mainboard/google/veyron_pinky/romstage.c
index f972ee26c8..1d7812b3e0 100644
--- a/src/mainboard/google/veyron_pinky/romstage.c
+++ b/src/mainboard/google/veyron_pinky/romstage.c
@@ -35,6 +35,7 @@
 #include <soc/rockchip/rk3288/clock.h>
 #include <soc/rockchip/rk3288/pwm.h>
 #include <soc/rockchip/rk3288/grf.h>
+#include <symbols.h>
 #include "timer.h"
 
 static void regulate_vdd_log(unsigned int mv)
@@ -64,9 +65,9 @@ void main(void)
 	start_romstage_time = timestamp_get();
 #endif
 	/* used for MMU and CBMEM setup, in MB */
-	u32 dram_start = (CONFIG_SYS_SDRAM_BASE >> 20);
-	u32 dram_size = CONFIG_DRAM_SIZE_MB;
-	u32 dram_end = dram_start + dram_size;
+	u32 dram_start_mb = (uintptr_t)_dram/MiB;
+	u32 dram_size_mb = CONFIG_DRAM_SIZE_MB;
+	u32 dram_end_mb = dram_start_mb + dram_size_mb;
 
 	console_init();
 
@@ -81,15 +82,15 @@ void main(void)
 #endif
 	mmu_init();
 	/* Device memory below DRAM is uncached. */
-	mmu_config_range(0, dram_start, DCACHE_OFF);
+	mmu_config_range(0, dram_start_mb, DCACHE_OFF);
 	/* DRAM is cached. */
-	mmu_config_range(dram_start, dram_size, DCACHE_WRITEBACK);
+	mmu_config_range(dram_start_mb, dram_size_mb, DCACHE_WRITEBACK);
 	/* A window for DMA is uncached. */
-	mmu_config_range(CONFIG_DRAM_DMA_START >> 20,
-			 CONFIG_DRAM_DMA_SIZE >> 20, DCACHE_OFF);
+	mmu_config_range((uintptr_t)_dma_coherent/MiB,
+			 _dma_coherent_size/MiB, DCACHE_OFF);
 	/* The space above DRAM is uncached. */
-	if (dram_end < 4096)
-		mmu_config_range(dram_end, 4096 - dram_end, DCACHE_OFF);
+	if (dram_end_mb < 4096)
+		mmu_config_range(dram_end_mb, 4096 - dram_end_mb, DCACHE_OFF);
 	dcache_mmu_enable();
 
 	cbmem_initialize_empty();
diff --git a/src/mainboard/ti/beaglebone/Makefile.inc b/src/mainboard/ti/beaglebone/Makefile.inc
index 71d749df2b..1a2143f75c 100644
--- a/src/mainboard/ti/beaglebone/Makefile.inc
+++ b/src/mainboard/ti/beaglebone/Makefile.inc
@@ -21,3 +21,7 @@ bootblock-y += bootblock.c
 romstage-y += romstage.c
 
 #ramstage-y += ramstage.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/ti/beaglebone/memlayout.ld b/src/mainboard/ti/beaglebone/memlayout.ld
new file mode 100644
index 0000000000..ff79e70ed5
--- /dev/null
+++ b/src/mainboard/ti/beaglebone/memlayout.ld
@@ -0,0 +1 @@
+#include <cpu/ti/am335x/memlayout.ld>