+++ /dev/null
-Summary
-=======
-
-This document describes how to use U-Boot on the Broadcom 7445 SoC, as
-a third stage bootloader loaded by Broadcom's BOLT bootloader.
-
-BOLT loads U-Boot as a generic ELF binary. Some U-Boot features such
-as networking are not yet available but other important features are,
-including:
-
- - ext4 file system traversal
-
- - support for loading FIT images
-
- - advanced scripting
-
- - support for FIT-provided DTBs instead of relying on the
- BOLT-provided DTB
-
-A customized version of this port has been used in production. The
-same approach may work on other BCM7xxx boards, with some
-configuration adjustments and memory layout experimentation.
-
-Build
-=====
-
-make bcm7445_defconfig
-make
-${CROSS_COMPILE}strip u-boot
-
-Run
-===
-
-To tell U-Boot which serial port to use for its console, set the
-"stdout-path" property in the "/chosen" node of the BOLT-generated
-device tree. For example:
-
-BOLT> dt add prop chosen stdout-path s serial0:115200n8
-
-Flash the u-boot binary into board storage, then invoke it from BOLT.
-For example:
-
-BOLT> boot -bsu -elf flash0.u-boot1
-
-This port assumes that I-cache and D-cache are already enabled when
-U-Boot is entered.
-
-Flattened Image Tree Support
-============================
-
-What follows is an example FIT image source file. Build it with:
-
-mkimage -f image.its image.itb
-
-Booting the resulting image.itb was tested on BOLT v1.20, with the
-following kernels:
-
-https://github.com/Broadcom/stblinux-3.14
-https://github.com/Broadcom/stblinux-4.1
-https://github.com/Broadcom/stblinux-4.9
-
-and with a generic ARMv7 root file system.
-
-image.its:
-/dts-v1/;
-/ {
- description = "BCM7445 FIT";
- images {
- kernel@1 {
- description = "Linux kernel";
- /*
- * This kernel image output format can be
- * generated with:
- *
- * make vmlinux
- * ${CROSS_COMPILE}objcopy -O binary -S vmlinux vmlinux.bin
- * gzip -9 vmlinux.bin
- *
- * For stblinux-3.14, the specific Broadcom
- * board type should be configured in the
- * kernel, for example CONFIG_BCM7445D0=y.
- */
- data = /incbin/("<vmlinux.bin.gz>");
- type = "kernel";
- arch = "arm";
- os = "linux";
- compression = "gzip";
- load = <0x8000>;
- entry = <0x8000>;
- hash@1 {
- algo = "sha256";
- };
- };
- ramdisk@1 {
- description = "Initramfs root file system";
- data = /incbin/("<initramfs.cpio.gz>");
- type = "ramdisk";
- arch = "arm";
- os = "linux";
- compression = "gzip";
- /*
- * Set the environment variable initrd_high to
- * 0xffffffff, and set "load" and "entry" here
- * to 0x0 to keep initramfs in-place and to
- * accommodate stblinux bmem/CMA reservations.
- */
- load = <0x0>;
- entry = <0x0>;
- hash@1 {
- algo = "sha256";
- };
- };
- fdt@1 {
- description = "Device tree dumped from BOLT";
- /*
- * This DTB should be similar to the
- * BOLT-generated device tree, after BOLT has
- * done its runtime modifications to it. For
- * example, it can be dumped from within
- * U-Boot (at ${fdtcontroladdr}), after BOLT
- * has loaded U-Boot. The result can be added
- * to the Linux source tree as a .dts file.
- *
- * To support modifications to the device tree
- * in-place in U-Boot, add to Linux's
- * arch/arm/boot/dts/Makefile:
- *
- * DTC_FLAGS ?= -p 4096
- *
- * This will leave some padding in the DTB and
- * thus reserve room for node additions.
- *
- * Also, set the environment variable fdt_high
- * to 0xffffffff to keep the DTB in-place and
- * to accommodate stblinux bmem/CMA
- * reservations.
- */
- data = /incbin/("<bolt-<version>.dtb");
- type = "flat_dt";
- arch = "arm";
- compression = "none";
- hash@1 {
- algo = "sha256";
- };
- };
- };
- configurations {
- default = "conf@bcm7445";
- conf@bcm7445 {
- description = "BCM7445 configuration";
- kernel = "kernel@1";
- ramdisk = "ramdisk@1";
- fdt = "fdt@1";
- };
- };
-};
--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0+
+.. Copyright (C) 2018, 2023 Thomas Fitzsimmons <fitzsim@fitzsim.org>
+
+BCM7445 and BCM7260
+===================
+
+This document describes how to use U-Boot on the Broadcom 7445 and
+Broadcom 7260 SoC, as a third stage bootloader loaded by Broadcom's
+BOLT bootloader.
+
+BOLT loads U-Boot as a generic ELF binary. Some U-Boot features such
+as networking are not implemented but other important features are,
+including:
+
+* ext4 file system traversal
+* support for loading FIT images
+* advanced scripting
+* support for FIT-provided DTBs instead of relying on the BOLT-provided DTB
+
+A customized version of this port has been used in production. The
+same approach may work on other BCM7xxx boards, with some
+configuration adjustments and memory layout experimentation.
+
+Configure
+---------
+
+BCM7445
+^^^^^^^
+
+.. code-block:: console
+
+ $ make bcm7445_defconfig
+
+BCM7260
+^^^^^^^
+
+.. code-block:: console
+
+ $ make bcm7260_defconfig
+
+Build
+-----
+
+.. code-block:: console
+
+ $ make
+ $ ${CROSS_COMPILE}strip u-boot
+
+Run
+---
+
+To tell U-Boot which serial port to use for its console, set the
+``stdout-path`` property in the ``/chosen`` node of the BOLT-generated
+device tree. For example:
+
+::
+
+ BOLT> dt add prop chosen stdout-path s serial0:115200n8
+
+Flash the ``u-boot`` binary into board storage, then invoke it from
+BOLT. For example:
+
+::
+
+ BOLT> boot -bsu -elf flash0.u-boot1
+
+This port assumes that I-cache and D-cache are already enabled when
+U-Boot is entered.
+
+Flattened Image Tree Support
+----------------------------
+
+What follows is an example FIT image source file. Build it with:
+
+.. code-block:: console
+
+ $ mkimage -f image.its image.itb
+
+Booting the resulting ``image.itb`` was tested on BOLT v1.20, with the
+following kernels:
+
+* https://github.com/Broadcom/stblinux-3.14
+* https://github.com/Broadcom/stblinux-4.1
+* https://github.com/Broadcom/stblinux-4.9
+
+and with a generic ARMv7 root file system.
+
+**image.its**
+
+::
+
+ /dts-v1/;
+ / {
+ description = "BCM7445 FIT";
+ images {
+ kernel@1 {
+ description = "Linux kernel";
+ /*
+ * This kernel image output format can be
+ * generated with:
+ *
+ * make vmlinux
+ * ${CROSS_COMPILE}objcopy -O binary -S vmlinux vmlinux.bin
+ * gzip -9 vmlinux.bin
+ *
+ * For stblinux-3.14, the specific Broadcom
+ * board type should be configured in the
+ * kernel, for example CONFIG_BCM7445D0=y.
+ */
+ data = /incbin/("<vmlinux.bin.gz>");
+ type = "kernel";
+ arch = "arm";
+ os = "linux";
+ compression = "gzip";
+ load = <0x8000>;
+ entry = <0x8000>;
+ hash@1 {
+ algo = "sha256";
+ };
+ };
+ ramdisk@1 {
+ description = "Initramfs root file system";
+ data = /incbin/("<initramfs.cpio.gz>");
+ type = "ramdisk";
+ arch = "arm";
+ os = "linux";
+ compression = "gzip";
+ /*
+ * Set the environment variable initrd_high to
+ * 0xffffffff, and set "load" and "entry" here
+ * to 0x0 to keep initramfs in-place and to
+ * accommodate stblinux bmem/CMA reservations.
+ */
+ load = <0x0>;
+ entry = <0x0>;
+ hash@1 {
+ algo = "sha256";
+ };
+ };
+ fdt@1 {
+ description = "Device tree dumped from BOLT";
+ /*
+ * This DTB should be similar to the
+ * BOLT-generated device tree, after BOLT has
+ * done its runtime modifications to it. For
+ * example, it can be dumped from within
+ * U-Boot (at ${fdtcontroladdr}), after BOLT
+ * has loaded U-Boot. The result can be added
+ * to the Linux source tree as a .dts file.
+ *
+ * To support modifications to the device tree
+ * in-place in U-Boot, add to Linux's
+ * arch/arm/boot/dts/Makefile:
+ *
+ * DTC_FLAGS ?= -p 4096
+ *
+ * This will leave some padding in the DTB and
+ * thus reserve room for node additions.
+ *
+ * Also, set the environment variable fdt_high
+ * to 0xffffffff to keep the DTB in-place and
+ * to accommodate stblinux bmem/CMA
+ * reservations.
+ */
+ data = /incbin/("<bolt-<version>.dtb");
+ type = "flat_dt";
+ arch = "arm";
+ compression = "none";
+ hash@1 {
+ algo = "sha256";
+ };
+ };
+ };
+ configurations {
+ default = "conf@bcm7445";
+ conf@bcm7445 {
+ description = "BCM7445 configuration";
+ kernel = "kernel@1";
+ ramdisk = "ramdisk@1";
+ fdt = "fdt@1";
+ };
+ };
+ };
projects / u-boot.git / commitdiff
