From a15a7aa47be25580413a49f9e8f33ba02a46ede7 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Mon, 1 Oct 2018 12:22:17 -0600 Subject: [PATCH] doc: Update docs for device tree in SPL, TPL Make a few small updates to indicate that device tree can be used in SPL and TPL. Signed-off-by: Simon Glass --- doc/README.fdt-control | 10 ++++++++++ doc/driver-model/README.txt | 3 ++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/doc/README.fdt-control b/doc/README.fdt-control index 88c0469..d6ab7bf 100644 --- a/doc/README.fdt-control +++ b/doc/README.fdt-control @@ -174,6 +174,16 @@ After board configuration is done, fdt supported u-boot can be build in two ways $ make DEVICE_TREE= +Relocation, SPL and TPL +----------------------- + +U-Boot can be divided into three phases: TPL, SPL and U-Boot proper. + +The full device tree is available to U-Boot proper, but normally only a subset +(or none at all) is available to TPL and SPL. See 'Pre-Relocation Support' and +'SPL Support' in doc/driver-model/README.txt for more details. + + Limitations ----------- diff --git a/doc/driver-model/README.txt b/doc/driver-model/README.txt index e949ff6..6085f92 100644 --- a/doc/driver-model/README.txt +++ b/doc/driver-model/README.txt @@ -832,7 +832,8 @@ Pre-Relocation Support For pre-relocation we simply call the driver model init function. Only drivers marked with DM_FLAG_PRE_RELOC or the device tree 'u-boot,dm-pre-reloc' flag are initialised prior to relocation. This helps -to reduce the driver model overhead. +to reduce the driver model overhead. This flag applies to SPL and TPL as +well, if device tree is enabled there. It is possible to limit this to specific relocation steps, by using the more specialized 'u-boot,dm-spl' and 'u-boot,dm-tpl' flags