old_contents: # Copyright 2017 Eficent Business and IT Consulting Services S.L.
  # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
  
  from odoo import fields, models
  
  
  class MrpBom(models.Model):
      _inherit = "mrp.bom"
  
      location_id = fields.Many2one(
          related='picking_type_id.default_location_dest_id',
          store=True,
      )
  
  
  class MrpBomLine(models.Model):
      _inherit = "mrp.bom.line"
  
      location_id = fields.Many2one(
          related='bom_id.picking_type_id.default_location_src_id',
          store=True,
      )
  
new_contents: # Copyright 2017 Eficent Business and IT Consulting Services S.L.
  # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
  
  from odoo import fields, models
  
  
  class MrpBom(models.Model):
      _inherit = "mrp.bom"
  
      location_id = fields.Many2one(
          related='picking_type_id.default_location_dest_id',
          readonly=True,
          store=True,
      )
  
  
  class MrpBomLine(models.Model):
      _inherit = "mrp.bom.line"
  
      location_id = fields.Many2one(
          related='bom_id.picking_type_id.default_location_src_id',
          readonly=True,
          store=True,
      )
  
subject: Make the related location readonly