[PATCH rtems-lwip] wscript: Allow deeper lwIP configuration

[Kinsey Moore]

This adds a basic configuration mechanism in config.ini to control which
BSPs are enabled and to alter lwIP's define/macro-based configuration
directives. Existing builds using --rtems-bsps are unaffected if
config.ini is not used.
---
 README  | 14 ++++++++++++++
 wscript | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/README b/README
index 99800bf..a8cbc21 100644
--- a/README
+++ b/README
@@ -30,3 +30,17 @@ git submodule update
 
 More `waf` arguments can be found by using:
 `./waf --help`
+
+Further Build Information
+-------------------------
+
+The BSPs configured to build may be specified on the waf configure command line
+with --rtems-bsps or they may be configured in config.ini as in RTEMS. The
+command line option will override the BSPs configured in config.ini, but options
+in config.ini will still be applied for enabled BSPs. Any additional
+configuration options desired in lwipopts.h may be specified in config.ini under
+the appropriate section as key/value pairs like so:
+
+[aarch64/xilinx_zynqmp_lp64_zu3eg]
+LWIP_IGMP=1
+ZYNQMP_USE_SGMII=1
diff --git a/wscript b/wscript
index 1546a3d..f1b919e 100644
--- a/wscript
+++ b/wscript
@@ -1,3 +1,5 @@
+#!/usr/bin/env python
+
 #
 # RTEMS Project (https://www.rtems.org/)
 #
@@ -28,7 +30,13 @@
 from __future__ import print_function
 from rtems_waf import rtems
 
+try:
+    import configparser
+except:
+    import ConfigParser as configparser
+
 import lwip
+import os
 import sys
 top = '.'
 
@@ -48,8 +56,58 @@ def options(opt):
     rtems.options(opt)
 
 
+def no_unicode(value):
+    if sys.version_info[0] > 2:
+        return value
+    if isinstance(value, unicode):
+        return str(value)
+    return value
+
+
+def get_config():
+    cp = configparser.ConfigParser()
+    filename = "config.ini"
+    if filename not in cp.read([filename]):
+        return None
+    return cp
+
+
+def get_configured_bsps(cp):
+    if not cp:
+        return "all"
+    bsps = []
+    for raw_bsp in cp.sections():
+        bsps.append(no_unicode(raw_bsp))
+    return ",".join(bsps)
+
+
+def get_configured_bsp_options(cp, arch, bsp):
+    if not cp:
+        return {}
+    options = {}
+    for config_option in cp.items(os.path.join(arch, bsp)):
+        opt_name = config_option[0].upper()
+        options[opt_name] = config_option[1]
+    return options
+
+
+def bsp_configure(conf, arch_bsp):
+    cp = get_config()
+    arch = rtems.arch(arch_bsp)
+    bsp = rtems.bsp(arch_bsp)
+    config_options = get_configured_bsp_options(cp, arch, bsp)
+    for key, val in config_options.items():
+        flag = "-D"+key+"="+val
+        conf.env.CFLAGS.append(flag)
+        conf.env.CXXFLAGS.append(flag)
+    lwip.bsp_configure(conf, arch_bsp)
+
+
 def configure(conf):
-    rtems.configure(conf, lwip.bsp_configure)
+    cp = get_config()
+    if conf.options.rtems_bsps == "all":
+        conf.options.rtems_bsps = get_configured_bsps(cp)
+    rtems.configure(conf, bsp_configure)
 
 
 def build(bld):
-- 
2.30.2