Add and consistently use wrapper macro for romstage static variables
x86 systems run their romstage as execute-in-place from flash, which
prevents them from having writable data segments. In several code pieces
that get linked into both romstage and ramstage, this has been worked
around by using a local variable and having the 'static' storage class
guarded by #ifndef __PRE_RAM__.
However, x86 is the only architecture using execute-in-place (for now),
so it does not make sense to impose the restriction globally. Rather
than fixing the #ifdef at every occurrence, this should really be
wrapped in a way that makes it easier to modify in a single place. The
chromeos/cros_vpd.c file already had a nice approach for a wrapper
macro, but unfortunately restricted it to one file... this patch moves
it to stddef.h and employs it consistently throughout coreboot.
BRANCH=nyan
BUG=None
TEST=Measured boot time on Nyan_Big before and after, confirmed that it
gained 6ms from caching the FMAP in vboot_loader.c.
Original-Change-Id: Ia53b94ab9c6a303b979db7ff20b79e14bc51f9f8
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/203033
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
(cherry picked from commit c8127e4ac9811517f6147cf019ba6a948cdaa4a5)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Change-Id: I44dacc10214351992b775aca52d6b776a74ee922
Reviewed-on: http://review.coreboot.org/8055
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)
diff --git a/src/include/stddef.h b/src/include/stddef.h
index 3a030e1..60e3459 100644
--- a/src/include/stddef.h
+++ b/src/include/stddef.h
@@ -49,4 +49,11 @@
#define ROMSTAGE_CONST
#endif
+/* Work around non-writable data segment in execute-in-place romstage on x86. */
+#if defined(__PRE_RAM__) && CONFIG_ARCH_X86
+#define MAYBE_STATIC
+#else
+#define MAYBE_STATIC static
+#endif
+
#endif /* STDDEF_H */
diff --git a/src/lib/lzma.c b/src/lib/lzma.c
index ea5f15f..8efa1e6 100644
--- a/src/lib/lzma.c
+++ b/src/lib/lzma.c
@@ -24,12 +24,7 @@
int res;
CLzmaDecoderState state;
SizeT mallocneeds;
-#if !defined(__PRE_RAM__)
- /* in ramstage, this can go in BSS */
- static
-#endif
- /* in pre-ram, it must go on the stack */
- unsigned char scratchpad[15980];
+ MAYBE_STATIC unsigned char scratchpad[15980];
unsigned char *cp;
memcpy(properties, src, LZMA_PROPERTIES_SIZE);
diff --git a/src/vendorcode/google/chromeos/cros_vpd.c b/src/vendorcode/google/chromeos/cros_vpd.c
index 26b01ee..df2b5bf 100644
--- a/src/vendorcode/google/chromeos/cros_vpd.c
+++ b/src/vendorcode/google/chromeos/cros_vpd.c
@@ -15,16 +15,6 @@
#include "lib_vpd.h"
#include "vpd_tables.h"
-/*
- * Static variables are available in ramstage (all platforms), and romstage for
- * some platforms (ex, ARM, which uses SRAM).
- */
-#if defined(__PRE_RAM__) && CONFIG_ARCH_X86
-#define STATIC_VAR
-#else
-#define STATIC_VAR static
-#endif
-
/* Currently we only support Google VPD 2.0, which has a fixed offset. */
enum {
GOOGLE_VPD_2_0_OFFSET = 0x600,
@@ -39,10 +29,10 @@
static int cros_vpd_load(uint8_t **vpd_address, int32_t *vpd_size)
{
- STATIC_VAR int cached = 0;
- STATIC_VAR uint8_t *cached_address = NULL;
- STATIC_VAR int32_t cached_size = 0;
- STATIC_VAR int result = -1;
+ MAYBE_STATIC int cached = 0;
+ MAYBE_STATIC uint8_t *cached_address = NULL;
+ MAYBE_STATIC int32_t cached_size = 0;
+ MAYBE_STATIC int result = -1;
struct google_vpd_info info;
int32_t base;
diff --git a/src/vendorcode/google/chromeos/fmap.c b/src/vendorcode/google/chromeos/fmap.c
index d758f57..a8425c0 100644
--- a/src/vendorcode/google/chromeos/fmap.c
+++ b/src/vendorcode/google/chromeos/fmap.c
@@ -92,10 +92,7 @@
int find_fmap_entry(const char name[], void **pointer)
{
-#ifndef __PRE_RAM__
- static
-#endif
- const struct fmap *fmap = NULL;
+ MAYBE_STATIC const struct fmap *fmap = NULL;
const struct fmap_area *area;
void *base = NULL;