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| author | Simon Glass <sjg@chromium.org> | 2018-10-01 12:22:17 -0600 |
|---|---|---|
| committer | Simon Glass <sjg@chromium.org> | 2018-10-09 04:40:27 -0600 |
| commit | a15a7aa47be25580413a49f9e8f33ba02a46ede7 (patch) | |
| tree | 403946143b2dacf22b36e4da3d05b16d486467c8 /doc | |
| parent | 343864afd7ca8c4f2d9d07a40929d897ec7c359c (diff) | |
| download | u-boot-a15a7aa47be25580413a49f9e8f33ba02a46ede7.tar.gz | |
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 <sjg@chromium.org>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.fdt-control | 10 | ||||
| -rw-r--r-- | doc/driver-model/README.txt | 3 |
2 files changed, 12 insertions, 1 deletions
diff --git a/doc/README.fdt-control b/doc/README.fdt-control index 88c04692f7..d6ab7bf570 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=<dts-file-name> +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 e949ff63ba..6085f927de 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 |