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Diffstat (limited to 'scripts/upgrade/README')
| -rw-r--r-- | scripts/upgrade/README | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/scripts/upgrade/README b/scripts/upgrade/README new file mode 100644 index 0000000..51760ea --- /dev/null +++ b/scripts/upgrade/README @@ -0,0 +1,23 @@ +Upgrade scripts for specific versions of the config file. +Each script must define a function `upgrade` that can +assume `${opt}` and `${val}` variables set on input. On +output, if `${opt}` is unset - so will be the corresponding +option. + +One thing to keep in mind is that this script may be invoked +on full config - or on a defconfig. Do not assume that all +options will be present! If an option is not specified, use +the value it had as a default for the fallback; to check if +it has been specified, use `$selected_opts` associative +array to check if it has been present in the config file +(otherwise, you an option not being set after sourcing the +previous version of the config is ambiguous - it could be +that the option is called out as `# CT_FOO is not set` (i.e. +selected as false) or not present at all (i.e. selected as +default). + +If it is not possible to determine the settings of an option +because a different controlling option is not set, either +err out (see CT_LIBC_UCLIBC_CUSTOM in v0 for an example) +or select a sane default and issue a warning (see CT_GDB_CUSTOM +in v0 for an example). |