[coreboot-gerrit] Patch set updated for coreboot: 103975f x86: Update the check for Forbidden global variables

[Patrick Georgi (pgeorgi@google.com)]

Patrick Georgi (pgeorgi at google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/7306

-gerrit

commit 103975f8b3f7a09ebf8b7683b45dc2285b637d59
Author: Furquan Shaikh <furquan at google.com>
Date:   Thu Oct 30 11:53:38 2014 -0700

    x86: Update the check for Forbidden global variables
    
    Add a section .illegal_globals to romstage and check that the section does not
    contain any variables while creating romstage.
    
    [pg: Handle individual AGESA special cases in the
    linker script instead of whitelisting everything
    remotely AGESA related in the Makefile.]
    
    Change-Id: I866681f51a44bc21770d32995c281b556a90c153
    Signed-off-by: Furquan Shaikh <furquan at google.com>
    Signed-off-by: Patrick Georgi <pgeorgi at google.com>
---
 src/arch/x86/Makefile.inc     |  5 +++--
 src/arch/x86/init/romstage.ld | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/arch/x86/Makefile.inc b/src/arch/x86/Makefile.inc
index f99ea15..55266f6 100644
--- a/src/arch/x86/Makefile.inc
+++ b/src/arch/x86/Makefile.inc
@@ -214,9 +214,10 @@ ifeq ($(CONFIG_COMPILER_LLVM_CLANG),y)
 else
 	$(CC_romstage) $(CFLAGS_romstage) -nostdlib -nostartfiles -static -o $@ -L$(obj) -T $(objgenerated)/romstage_null.ld -Wl,--wrap,__divdi3 -Wl,--wrap,__udivdi3 -Wl,--wrap,__moddi3 -Wl,--wrap,__umoddi3 -Wl,--start-group $(romstage-objs) $(romstage-libs) $(LIBGCC_FILE_NAME_romstage) -Wl,--end-group
 endif
-	$(NM_romstage) $@ | grep -q " [DdBb] "; if [ $$? -eq 0 ]; then \
+	$(OBJCOPY_romstage) --only-section .illegal_globals $(@) $(objcbfs)/romstage_null.offenders && \
+	$(NM_romstage) $(objcbfs)/romstage_null.offenders | grep -q ""; if [ $$? -eq 0 ]; then \
 		echo "Forbidden global variables in romstage:"; \
-		$(NM_romstage) $@ | grep " [DdBb] "; test "$(CONFIG_CPU_AMD_AGESA)" = y; \
+		$(NM_romstage) $(objcbfs)/romstage_null.offenders; false; \
 		else true; fi
 
 $(objcbfs)/romstage_xip.debug: $$(romstage-objs) $(objgenerated)/romstage_xip.ld $$(romstage-libs)
diff --git a/src/arch/x86/init/romstage.ld b/src/arch/x86/init/romstage.ld
index d6eb511..99bcc8e 100644
--- a/src/arch/x86/init/romstage.ld
+++ b/src/arch/x86/init/romstage.ld
@@ -65,5 +65,20 @@ SECTIONS
 		preram_cbmem_console = .;
 	}
 
+	/* Global variables are not allowed in romstage
+	 * This section is checked during stage creation to ensure
+	 * that there are no global variables present
+	 */
+
+	. = 0xffffff00;
+	.illegal_globals . : {
+		*(EXCLUDE_FILE (*/libagesa.*.a: */buildOpts.romstage.o */agesawrapper.romstage.o */cpu/amd/agesa/*.romstage.o */vendorcode/amd/agesa/* */vendorcode/amd/cimx/*) .data)
+		*(.data.*)
+		*(.bss)
+		*(.bss.*)
+		*(.sbss)
+		*(.sbss.*)
+	}
+
 	_bogus = ASSERT((SIZEOF(.car.data) + CONFIG_CONSOLE_PRERAM_BUFFER_SIZE <= CONFIG_DCACHE_RAM_SIZE), "Cache as RAM area is too full");
 }