Add documentation for the pre-reloc property in SPL and TPL device-tree: - u-boot,dm-pre-proper - u-boot,dm-pre-reloc - u-boot,dm-spl - u-boot,dm-tpl
Signed-off-by: Patrick Delaunay patrick.delaunay@st.com Reviewed-by: Simon Glass sjg@chromium.org ---
Changes in v2: - rebase on master
doc/README.SPL | 16 ++++++++++++++++ doc/README.TPL | 4 ++++ doc/driver-model/README.txt | 4 ++++ include/dm/ofnode.h | 6 ++++-- include/dm/util.h | 6 ++++-- 5 files changed, 32 insertions(+), 4 deletions(-)
diff --git a/doc/README.SPL b/doc/README.SPL index 7a30fef..6eed83f 100644 --- a/doc/README.SPL +++ b/doc/README.SPL @@ -66,6 +66,22 @@ CONFIG_SPL_SPI_LOAD (drivers/mtd/spi/spi_spl_load.o) CONFIG_SPL_RAM_DEVICE (common/spl/spl.c) CONFIG_SPL_WATCHDOG_SUPPORT (drivers/watchdog/libwatchdog.o)
+Device tree +----------- +The U-Boot device tree is filtered by the fdtgrep tools during the build +process to generate a much smaller device tree used in SPL (spl/u-boot-spl.dtb) +with: +- the mandatory nodes (/alias, /chosen, /config) +- the nodes with one pre-relocation property: + 'u-boot,dm-pre-reloc' or 'u-boot,dm-spl' + +ftgrep is also used to remove: +- the properties defined in CONFIG_OF_SPL_REMOVE_PROPS +- all the pre-relocation properties + ('u-boot,dm-pre-reloc', 'u-boot,dm-spl' and 'u-boot,dm-tpl') + +All the nodes remaining in the SPL devicetree are bound +(see driver-model/README.txt).
Debugging --------- diff --git a/doc/README.TPL b/doc/README.TPL index 980debe..c94129f 100644 --- a/doc/README.TPL +++ b/doc/README.TPL @@ -34,6 +34,10 @@ determine which SPL options to choose based on whether CONFIG_TPL_BUILD is set. Source files can be compiled for TPL with options choosed in the board config file.
+TPL use a small device tree (u-boot-tpl.dtb), containing only the nodes with +the pre-relocation properties: 'u-boot,dm-pre-reloc' and 'u-boot,dm-tpl' +(see README.SPL for details). + For example:
spl/Makefile: diff --git a/doc/driver-model/README.txt b/doc/driver-model/README.txt index 07b120d..532a771 100644 --- a/doc/driver-model/README.txt +++ b/doc/driver-model/README.txt @@ -849,6 +849,10 @@ in the device tree node. For U-Boot proper you can use 'u-boot,dm-pre-proper' which means that it will be processed (and a driver bound) in U-Boot proper prior to relocation, but will not be available in SPL or TPL.
+To reduce the size of SPL and TPL, only the nodes with pre-relocation properties +('u-boot,dm-pre-reloc', 'u-boot,dm-spl' or 'u-boot,dm-tpl') are keept in their +device trees (see README.SPL for details); the remaining nodes are always bound. + Then post relocation we throw that away and re-init driver model again. For drivers which require some sort of continuity between pre- and post-relocation devices, we can provide access to the pre-relocation diff --git a/include/dm/ofnode.h b/include/dm/ofnode.h index d206ee2..b45da5e 100644 --- a/include/dm/ofnode.h +++ b/include/dm/ofnode.h @@ -662,12 +662,14 @@ int ofnode_read_simple_size_cells(ofnode node); * After relocation and jumping into the real U-Boot binary it is possible to * determine if a node was bound in one of SPL/TPL stages. * - * There are 3 settings currently in use - * - + * There are 4 settings currently in use + * - u-boot,dm-pre-proper: U-Boot proper pre-relocation only * - u-boot,dm-pre-reloc: legacy and indicates any of TPL or SPL * Existing platforms only use it to indicate nodes needed in * SPL. Should probably be replaced by u-boot,dm-spl for * new platforms. + * - u-boot,dm-spl: SPL and U-Boot pre-relocation + * - u-boot,dm-tpl: TPL and U-Boot pre-relocation * * @node: node to check * @return true if node is needed in SPL/TL, false otherwise diff --git a/include/dm/util.h b/include/dm/util.h index 60d3b93..348c2ac 100644 --- a/include/dm/util.h +++ b/include/dm/util.h @@ -52,12 +52,14 @@ static inline void dm_dump_devres(void) * it is possible to determine if a node was bound in one of * SPL/TPL stages. * - * There are 3 settings currently in use - * - + * There are 4 settings currently in use + * - u-boot,dm-pre-proper: U-Boot proper pre-relocation only * - u-boot,dm-pre-reloc: legacy and indicates any of TPL or SPL * Existing platforms only use it to indicate nodes needed in * SPL. Should probably be replaced by u-boot,dm-spl for * existing platforms. + * - u-boot,dm-spl: SPL and U-Boot pre-relocation + * - u-boot,dm-tpl: TPL and U-Boot pre-relocation * @node: of node * * Returns true if node is needed in SPL/TL, false otherwise.