From 2c4e689bc1ed4440d0d95b3b350ce872e7f75865 Mon Sep 17 00:00:00 2001
From: James Clarke <jrtc27@jrtc27.com>
Date: Mon, 3 Feb 2020 00:53:17 +0000
Subject: Support manually zeroing out BSS when booting (#188)

Some ELF loaders, in particular gdb's load command for dynamically
loading files into memory, which is often used to load binaries onto
FPGAs over JTAG, do not zero out BSS, leaving the memory in whatever
state it was previously in. Thus, introduce a new --enable-zero-bss
configure flag, which will include code to zero out BSS when booting.
---
 configure | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

(limited to 'configure')

diff --git a/configure b/configure
index 587f1f6..9d2c146 100755
--- a/configure
+++ b/configure
@@ -675,6 +675,7 @@ with_arch
 with_abi
 enable_print_device_tree
 with_mem_start
+enable_zero_bss
 enable_optional_subprojects
 enable_vm
 enable_logo
@@ -1314,6 +1315,7 @@ Optional Features:
   --enable-stow           Enable stow-based install
   --enable-print-device-tree
                           Print DTS when booting
+  --enable-zero-bss       Manually zero out BSS when booting
   --enable-optional-subprojects
                           Enable all optional subprojects
   --disable-vm            Disable virtual memory
@@ -4122,6 +4124,19 @@ else
 fi
 
 
+# Check whether --enable-zero-bss was given.
+if test "${enable_zero_bss+set}" = set; then :
+  enableval=$enable_zero_bss;
+fi
+
+if test "x$enable_zero_bss" = "xyes"; then :
+
+
+$as_echo "#define ZERO_BSS /**/" >>confdefs.h
+
+
+fi
+
 #-------------------------------------------------------------------------
 # MCPPBS subproject list
 #-------------------------------------------------------------------------
-- 
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