diff options
Diffstat (limited to 'doc')
-rw-r--r-- | doc/android/avb2.txt (renamed from doc/README.avb2) | 0 | ||||
-rw-r--r-- | doc/android/bcb.txt | 89 | ||||
-rw-r--r-- | doc/android/fastboot.txt (renamed from doc/README.android-fastboot) | 0 | ||||
-rw-r--r-- | doc/device-tree-bindings/pci_endpoint/cdns,cdns-pcie-ep.txt | 18 | ||||
-rw-r--r-- | doc/uImage.FIT/signature.txt | 2 |
5 files changed, 108 insertions, 1 deletions
diff --git a/doc/README.avb2 b/doc/android/avb2.txt index a29cee1b6f..a29cee1b6f 100644 --- a/doc/README.avb2 +++ b/doc/android/avb2.txt diff --git a/doc/android/bcb.txt b/doc/android/bcb.txt new file mode 100644 index 0000000000..7b7177cacf --- /dev/null +++ b/doc/android/bcb.txt @@ -0,0 +1,89 @@ +Android Bootloader Control Block (BCB) + +The purpose behind this file is to: + - give an overview of BCB w/o duplicating public documentation + - describe the main BCB use-cases which concern U-Boot + - reflect current support status in U-Boot + - mention any relevant U-Boot build-time tunables + - precisely exemplify one or more use-cases + +Additions and fixes are welcome! + + +1. OVERVIEW +--------------------------------- +Bootloader Control Block (BCB) is a well established term/acronym in +the Android namespace which refers to a location in a dedicated raw +(i.e. FS-unaware) flash (e.g. eMMC) partition, usually called "misc", +which is used as media for exchanging messages between Android userspace +(particularly recovery [1]) and an Android-capable bootloader. + +On higher level, BCB provides a way to implement a subset of Android +Bootloader Requirements [2], amongst which are: + - Android-specific bootloader flow [3] + - Get the "reboot reason" (and act accordingly) [4] + - Get/pass a list of commands from/to recovery [1] + - TODO + + +2. 'BCB'. SHELL COMMAND OVERVIEW +----------------------------------- +The 'bcb' command provides a CLI to facilitate the development of the +requirements enumerated above. Below is the command's help message: + +=> bcb +bcb - Load/set/clear/test/dump/store Android BCB fields + +Usage: +bcb load <dev> <part> - load BCB from mmc <dev>:<part> +bcb set <field> <val> - set BCB <field> to <val> +bcb clear [<field>] - clear BCB <field> or all fields +bcb test <field> <op> <val> - test BCB <field> against <val> +bcb dump <field> - dump BCB <field> +bcb store - store BCB back to mmc + +Legend: +<dev> - MMC device index containing the BCB partition +<part> - MMC partition index or name containing the BCB +<field> - one of {command,status,recovery,stage,reserved} +<op> - the binary operator used in 'bcb test': + '=' returns true if <val> matches the string stored in <field> + '~' returns true if <val> matches a subset of <field>'s string +<val> - string/text provided as input to bcb {set,test} + NOTE: any ':' character in <val> will be replaced by line feed + during 'bcb set' and used as separator by upper layers + + +3. 'BCB'. EXAMPLE OF GETTING REBOOT REASON +----------------------------------- +if bcb load 1 misc; then + # valid BCB found + if bcb test command = bootonce-bootloader; then + bcb clear command; bcb store; + # do the equivalent of AOSP ${fastbootcmd} + # i.e. call fastboot + else if bcb test command = boot-recovery; then + bcb clear command; bcb store; + # do the equivalent of AOSP ${recoverycmd} + # i.e. do anything required for booting into recovery + else + # boot Android OS normally + fi +else + # corrupted/non-existent BCB + # report error or boot non-Android OS (platform-specific) +fi + + +4. ENABLE ON YOUR BOARD +----------------------------------- +The following Kconfig options must be enabled: +CONFIG_PARTITIONS=y +CONFIG_MMC=y +CONFIG_BCB=y + +[1] https://android.googlesource.com/platform/bootable/recovery +[2] https://source.android.com/devices/bootloader +[3] https://patchwork.ozlabs.org/patch/746835/ + ("[U-Boot,5/6] Initial support for the Android Bootloader flow") +[4] https://source.android.com/devices/bootloader/boot-reason diff --git a/doc/README.android-fastboot b/doc/android/fastboot.txt index 431191c473..431191c473 100644 --- a/doc/README.android-fastboot +++ b/doc/android/fastboot.txt diff --git a/doc/device-tree-bindings/pci_endpoint/cdns,cdns-pcie-ep.txt b/doc/device-tree-bindings/pci_endpoint/cdns,cdns-pcie-ep.txt new file mode 100644 index 0000000000..7705430559 --- /dev/null +++ b/doc/device-tree-bindings/pci_endpoint/cdns,cdns-pcie-ep.txt @@ -0,0 +1,18 @@ +* Cadence PCIe endpoint controller + +Required properties: +- compatible: Should contain "cdns,cdns-pcie-ep" to identify the IP used. +- reg: Should contain the controller register base address. + +Optional properties: +- max-functions: Maximum number of functions that can be configured (default 1). +- cdns,max-outbound-regions: Set to maximum number of outbound regions (default 8) + +Example: + +pcie_ep@fc000000 { + compatible = "cdns,cdns-pcie-ep"; + reg = <0x0 0xfc000000 0x0 0x01000000>; + cdns,max-outbound-regions = <16>; + max-functions = /bits/ 8 <8>; +}; diff --git a/doc/uImage.FIT/signature.txt b/doc/uImage.FIT/signature.txt index bfff6fdc73..78b59e7203 100644 --- a/doc/uImage.FIT/signature.txt +++ b/doc/uImage.FIT/signature.txt @@ -335,7 +335,7 @@ CONFIG_RSA - enable RSA algorithm for signing WARNING: When relying on signed FIT images with required signature check the legacy image format is default disabled by not defining -CONFIG_IMAGE_FORMAT_LEGACY +CONFIG_LEGACY_IMAGE_FORMAT Testing ------- |