lualoader: allow the local module to filter out the BE listHEADmain

This allows something like the following local.lua to install a filter
to implement its own notion of hidden BEs using a naming convention of
a leading dot to hide them:

-- file: /boot/lua/local.lua
local core = require("core")

local function be_hide(be)
    if core.isSingleUserBoot() then
        -- All BEs are accepted for single-user
        return true
    end

    local name = be:match("/([^/]+)$")
    if not name then
        -- Accept malformed BEs, for whatever reason
        return true
    end

    return name:match("^%.") == nil
end

if core.bootenvFilter then
    -- Just in case we need to be compatible with older versions of
    -- core.lua without the filtering functionality.
    core.bootenvFilter(be_hide)
end
-- EOF

Requested by:	Marek Zarychta
Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D55359

0 files changed, 0 insertions, 0 deletions