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authorSimon Glass <sjg@chromium.org>2018-10-01 12:22:17 -0600
committerSimon Glass <sjg@chromium.org>2018-10-09 04:40:27 -0600
commita15a7aa47be25580413a49f9e8f33ba02a46ede7 (patch)
tree403946143b2dacf22b36e4da3d05b16d486467c8
parent343864afd7ca8c4f2d9d07a40929d897ec7c359c (diff)
downloadu-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>
-rw-r--r--doc/README.fdt-control10
-rw-r--r--doc/driver-model/README.txt3
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