diff options
author | Tom Rini <trini@konsulko.com> | 2018-11-16 08:37:50 -0500 |
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committer | Tom Rini <trini@konsulko.com> | 2018-11-16 08:37:50 -0500 |
commit | 1d6edcbfed2af33c748f2beb399810a0441888da (patch) | |
tree | fe88d63e5ef1dbe1915f90e02429e8b6934859da /doc/driver-model | |
parent | f6206f8587fc7ec82a57dbbeb5de0f94b3c2ef49 (diff) | |
parent | 4c6e27f63c88d065a98f438085dfc36af47d3a23 (diff) |
Merge tag 'pull-14nov18' of git://git.denx.de/u-boot-dm
- virtio implementation and supporting patches
- DM_FLAG_PRE_RELOC fixes
- regmap improvements
- minor buildman and sandbox things
Diffstat (limited to 'doc/driver-model')
-rw-r--r-- | doc/driver-model/README.txt | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/doc/driver-model/README.txt b/doc/driver-model/README.txt index 36541630a2..07b120d512 100644 --- a/doc/driver-model/README.txt +++ b/doc/driver-model/README.txt @@ -830,10 +830,18 @@ 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. This flag applies to SPL and TPL as -well, if device tree is enabled there. +drivers marked with DM_FLAG_PRE_RELOC or the device tree 'u-boot,dm-pre-reloc' +property are initialised prior to relocation. This helps to reduce the driver +model overhead. This flag applies to SPL and TPL as well, if device tree is +enabled (CONFIG_OF_CONTROL) there. + +Note when device tree is enabled, the device tree 'u-boot,dm-pre-reloc' +property can provide better control granularity on which device is bound +before relocation. While with DM_FLAG_PRE_RELOC flag of the driver all +devices with the same driver are bound, which requires allocation a large +amount of memory. When device tree is not used, DM_FLAG_PRE_RELOC is the +only way for statically declared devices via U_BOOT_DEVICE() to be bound +prior to relocation. 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 |