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authorTom Rini <trini@konsulko.com>2018-12-10 07:16:33 -0500
committerTom Rini <trini@konsulko.com>2018-12-10 07:16:33 -0500
commit7ff485c68b7e5573e5a4a877066e98398283a24f (patch)
tree8070ad8de0b18240ee67e1c8b847afc37bdb2d5d /doc/README.fdt-control
parent7504e9e75f76a5101b47cd32851ad7bd4ea8ff70 (diff)
parent19f8c4dfb6e744a31da59bdd23b24d144152f1dc (diff)
Merge branch 'master' of git://git.denx.de/u-boot-i2c
- DM_I2C_COMPAT removal for all ti platforms from Jean-Jacques Hiblot - Fix in i2c command help output from Chirstoph Muellner.
Diffstat (limited to 'doc/README.fdt-control')
-rw-r--r--doc/README.fdt-control18
1 files changed, 18 insertions, 0 deletions
diff --git a/doc/README.fdt-control b/doc/README.fdt-control
index d6ab7bf570..446401c9e9 100644
--- a/doc/README.fdt-control
+++ b/doc/README.fdt-control
@@ -184,6 +184,24 @@ The full device tree is available to U-Boot proper, but normally only a subset
'SPL Support' in doc/driver-model/README.txt for more details.
+Using several DTBs in the SPL (CONFIG_SPL_MULTI_DTB)
+----------------------------------------------------
+In some rare cases it is desirable to let SPL be able to select one DTB among
+many. This usually not very useful as the DTB for the SPL is small and usually
+fits several platforms. However the DTB sometimes include information that do
+work on several platforms (like IO tuning parameters).
+In this case it is possible to use CONFIG_SPL_MULTI_DTB. This option appends to
+the SPL a FIT image containing several DTBs listed in SPL_OF_LIST.
+board_fit_config_name_match() is called to select the right DTB.
+
+If board_fit_config_name_match() relies on DM (DM driver to access an EEPROM
+containing the board ID for example), it possible to start with a generic DTB
+and then switch over to the right DTB after the detection. For this purpose,
+the platform code must call fdtdec_resetup(). Based on the returned flag, the
+platform may have to re-initiliaze the DM subusystem using dm_uninit() and
+dm_init_and_scan().
+
+
Limitations
-----------