[OE-core] [OE-CORE][krogoth][PATCH]] syslinux.bbclass: Added configurable SYSLINUX_ALLOWOPTIONS variable

[Davis, Michael]

The new variable allows for images to be created without an
editable boot line in syslinux.  Default behavior remains unchanged.

Backport from master (935578c139a260c18e437419be82d7fd7e8be81a)
---
 meta/classes/syslinux.bbclass | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/meta/classes/syslinux.bbclass b/meta/classes/syslinux.bbclass
index 4fcb0c5..52fb51f 100644
--- a/meta/classes/syslinux.bbclass
+++ b/meta/classes/syslinux.bbclass
@@ -30,6 +30,7 @@ SYSLINUX_SERIAL_TTY ?= "console=ttyS0,115200"
 SYSLINUX_PROMPT ?= "0"
 SYSLINUX_TIMEOUT ?= "50"
 AUTO_SYSLINUXMENU ?= "1"
+SYSLINUX_ALLOWOPTIONS ?= "1"
 SYSLINUX_ROOT ?= "${ROOT}"
 SYSLINUX_CFG_VM  ?= "${S}/syslinux_vm.cfg"
 SYSLINUX_CFG_LIVE ?= "${S}/syslinux_live.cfg"
@@ -114,7 +115,12 @@ python build_syslinux_cfg () {
         for opt in opts.split(';'):
             cfgfile.write('%s\n' % opt)
 
-    cfgfile.write('ALLOWOPTIONS 1\n');
+    allowoptions = d.getVar('SYSLINUX_ALLOWOPTIONS', True)
+    if allowoptions:
+        cfgfile.write('ALLOWOPTIONS %s\n' % allowoptions)
+    else:
+        cfgfile.write('ALLOWOPTIONS 1\n')
+
     syslinux_default_console = d.getVar('SYSLINUX_DEFAULT_CONSOLE', True)
     syslinux_serial_tty = d.getVar('SYSLINUX_SERIAL_TTY', True)
     syslinux_serial = d.getVar('SYSLINUX_SERIAL', True)
-- 
2.5.5