Add back missing comments to build-essential chunk morphs

These will have been lost in the automated chunks-in-definitions
transition.

1 files changed, 19 insertions, 0 deletions

diff --git a/strata/armv7lhf-cross-toolchain/armv7lhf-cross-gcc-nolibc.morph b/strata/armv7lhf-cross-toolchain/armv7lhf-cross-gcc-nolibc.morph
index 9f993bc0..d164a60b 100644
--- a/strata/armv7lhf-cross-toolchain/armv7lhf-cross-gcc-nolibc.morph
+++ b/strata/armv7lhf-cross-toolchain/armv7lhf-cross-gcc-nolibc.morph
@@ -1,7 +1,20 @@
 name: armv7lhf-cross-gcc-nolibc
 kind: chunk
+
 configure-commands:
 - mkdir o
+
+# Configure flag notes:
+#  1. Standard flags. See gcc.morph.
+#  2. Our binutils is for the final $TARGET, rather than the intermediate
+#     target our GCC is being built for, so we need to set
+#     with-build-time-tools to get it to find our binutils at
+#     build-time and with-as and with-ld so our temporary GCC uses
+#     the appropriate tools when it compiles our libc, rather than
+#     trying to use $TARGET_STAGE1-as when producing binaries.
+#  3. Disable stuff that doesn't work when building a cross compiler
+#     without an existing libc, and generally try to keep this build as
+#     simple as possible.
 - |
   export MORPH_ARCH=armv7lhf
   export TARGET=armv7lhf-baserock-linux-gnueabi
@@ -25,10 +38,16 @@ configure-commands:
             --disable-shared --disable-threads --disable-target-libiberty \
             --disable-target-zlib --without-headers --with-newlib \
             --with-system-zlib
+
 build-commands:
 - cd o && make
+
 install-commands:
 - cd o && make DESTDIR="$DESTDIR" install
+
+# The file libgcc_eh is required during eglibc's build, but is not created
+# because we built GCC with --disable-shared. This is a workaround for
+# eglibc's build system being slightly broken.
 - |
   export TARGET_STAGE1=armv7lhf-none-linux-gnueabi
   libgcc_filename="$("$DESTDIR$PREFIX/bin/$TARGET_STAGE1-gcc" -print-libgcc-file-name)"