Stefan Reinauer (stefan.reinauer@coreboot.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/8055
-gerrit
commit 2cfae5490aced293a5351eea8b240f8bb80cc55b Author: Julius Werner jwerner@chromium.org Date: Fri Jun 6 16:10:56 2014 -0700
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 --- src/include/stddef.h | 7 +++++++ src/lib/lzma.c | 7 +------ src/vendorcode/google/chromeos/cros_vpd.c | 18 ++++-------------- src/vendorcode/google/chromeos/fmap.c | 5 +---- 4 files changed, 13 insertions(+), 24 deletions(-)
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 @@ typedef unsigned int wint_t; #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 @@ unsigned long ulzma(unsigned char * src, unsigned char * dst) 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 @@ struct vpd_gets_arg {
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 @@ const struct fmap_area *find_fmap_area(const struct fmap *fmap,
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;