X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=doc%2FREADME.distro;h=5076bebd1808672073067e048912f7407b498f8d;hb=0e2afc8368b632ffb195d588ec2315ffbbf0a7e9;hp=9e4722a86ee562fdc80b675f5be9d30e30e61597;hpb=28fd00b7770b70caa84fac186dcbb09b65eebe5a;p=oweals%2Fu-boot.git diff --git a/doc/README.distro b/doc/README.distro index 9e4722a86e..5076bebd18 100644 --- a/doc/README.distro +++ b/doc/README.distro @@ -1,9 +1,8 @@ +SPDX-License-Identifier: GPL-2.0+ /* * (C) Copyright 2014 Red Hat Inc. * Copyright (c) 2014-2015, NVIDIA CORPORATION. All rights reserved. * Copyright (C) 2015 K. Merker - * - * SPDX-License-Identifier: GPL-2.0+ */ Generic Distro Configuration Concept @@ -162,11 +161,15 @@ U-Boot Implementation Enabling the distro options --------------------------- +In your board's defconfig, enable the DISTRO_DEFAULTS option by adding +a line with "CONFIG_DISTRO_DEFAULTS=y". If you want to enable this +from Kconfig itself, for e.g. all boards using a specific SoC then +add a "imply DISTRO_DEFAULTS" to your SoC CONFIG option. + In your board configuration file, include the following: ------------------------------------------------------------ #ifndef CONFIG_SPL_BUILD -#include #include #endif ------------------------------------------------------------ @@ -182,7 +185,7 @@ Finally, a few options that are mostly relevant only when using U-Boot- specific boot.scr scripts are enabled. This enables distros to generate a U-Boot-specific boot.scr script rather than extlinux.conf as the boot configuration file. While doing so is fully supported, and - exposes enough parameterization to boot.scr to +CONFIG_DISTRO_DEFAULTS exposes enough parameterization to boot.scr to allow for board-agnostic boot.scr content, this document recommends that distros generate extlinux.conf rather than boot.scr. extlinux.conf is intended to work across multiple bootloaders, whereas boot.scr will only work with @@ -243,7 +246,19 @@ kernel_addr_r: A size of 16MB for the kernel is likely adequate. -pxe_addr_r: +kernel_comp_addr_r: + Optional. This is only required if user wants to boot Linux from a compressed + Image(.gz, .bz2, .lzma, .lzo) using booti command. It represents the location + in RAM where the compressed Image will be decompressed temporarily. Once the + decompression is complete, decompressed data will be moved kernel_addr_r for + booting. + +kernel_comp_size: + Optional. This is only required if user wants to boot Linux from a compressed + Image using booti command. It represents the size of the compressed file. The + size has to at least the size of loaded image for decompression to succeed. + +pxefile_addr_r: Mandatory. The location in RAM where extlinux.conf will be loaded to prior to processing. @@ -289,7 +304,7 @@ Each entry in the macro defines a single boot device (e.g. a specific eMMC device or SD card) or type of boot device (e.g. USB disk). The parameters to the func macro (passed in by the internal implementation of the header) are: -- Upper-case disk type (MMC, SATA, SCSI, IDE, USB, DHCP, PXE). +- Upper-case disk type (MMC, SATA, SCSI, IDE, USB, DHCP, PXE, VIRTIO). - Lower-case disk type (same options as above). - ID of the specific disk (MMC only) or ignored for other types. @@ -341,6 +356,21 @@ scan_dev_for_scripts: If you want to disable boot.scr on all disks, set the value to something innocuous, e.g. setenv scan_dev_for_scripts true. +boot_net_usb_start: + + If you want to prevent USB enumeration by distro boot commands which execute + network operations, set the value to something innocuous, e.g. setenv + boot_net_usb_start true. This would be useful if you know your Ethernet + device is not attached to USB, and you wish to increase boot speed by + avoiding unnecessary actions. + +boot_net_pci_enum: + + If you want to prevent PCI enumeration by distro boot commands which execute + network operations, set the value to something innocuous, e.g. setenv + boot_net_pci_enum true. This would be useful if you know your Ethernet + device is not attached to PCI, and you wish to increase boot speed by + avoiding unnecessary actions. Interactively booting from a specific device at the u-boot prompt ================================================================= @@ -380,6 +410,7 @@ The list of possible targets consists of: * scsi * ide * usb + * virtio Other *boot* variables than the ones defined above are only for internal use of the boot environment and are not guaranteed to exist or work in the same