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author | Tom Rini <trini@konsulko.com> | 2018-12-10 07:16:33 -0500 |
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committer | Tom Rini <trini@konsulko.com> | 2018-12-10 07:16:33 -0500 |
commit | 7ff485c68b7e5573e5a4a877066e98398283a24f (patch) | |
tree | 8070ad8de0b18240ee67e1c8b847afc37bdb2d5d /doc | |
parent | 7504e9e75f76a5101b47cd32851ad7bd4ea8ff70 (diff) | |
parent | 19f8c4dfb6e744a31da59bdd23b24d144152f1dc (diff) | |
download | u-boot-7ff485c68b7e5573e5a4a877066e98398283a24f.zip u-boot-7ff485c68b7e5573e5a4a877066e98398283a24f.tar.gz u-boot-7ff485c68b7e5573e5a4a877066e98398283a24f.tar.bz2 |
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')
-rw-r--r-- | doc/README.fdt-control | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/doc/README.fdt-control b/doc/README.fdt-control index d6ab7bf..446401c 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 ----------- |