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author | Julius Werner <jwerner@chromium.org> | 2015-01-27 15:40:47 -0800 |
---|---|---|
committer | Patrick Georgi <pgeorgi@google.com> | 2015-04-13 12:21:02 +0200 |
commit | 5d686229e8f808c65934c17da9313e758b4ef9e9 (patch) | |
tree | f5e19fe280e636ce9714e3c68df1ea32e8574fd0 /src/drivers | |
parent | b9d961550ce07951b472ae558281e288413ab445 (diff) | |
download | coreboot-staging-5d686229e8f808c65934c17da9313e758b4ef9e9.zip coreboot-staging-5d686229e8f808c65934c17da9313e758b4ef9e9.tar.gz |
elog: Correct behavior when FMAP section doesn't exist on ChromeOS
The elog driver has a really stupid bug that checks a result which is
stored in an unsigned variable for < 0. Surprisingly GCC does not catch
this nonsense right now, and I spent an hour trying out different
warning options without finding one that doesn't also bring a load of
stupid and unavoidable false positives (the biggest offender being
-Wtype-limits, which does exactly what we'd want except for flagging
things like if ((u8)var >= CONFIG_VAR_MIN) where the VAR_MIN Kconfig may
or may not be 0).
So, the only thing we can do is fix this one and wait for the next time
something like that blows up. -.- Also change some more code to make the
behavior more explicit (the old code already intended to work this way
since flash_base is statically initialized to 0, never assigned in the
error path and checked later in elog_init()... but there was an error
message that incorrectly claimed a different fallback behavior, and
explicitly assigning the values makes this easier to see). Finally, add
another state to the elog_initialized variable to avoid trying to
reinitialize a broken eventlog on every event (if it doesn't work the
first time, chances are that it won't work later on during the same boot
either).
BRANCH=None
BUG=chrome-os-partner:35940
TEST=Flashed Jerry with RO 6588.4 and RW 6588.23, observed how it now
cleanly enters recovery mode without blowing its bootblock away with
stray eventlog entries.
Change-Id: I0e5348ba961ce4835c30f7108a2453522095f2ee
Signed-off-by: Stefan Reinauer <reinauer@chromium.org>
Original-Commit-Id: f9798dbf0c2b2e337062ecd84d0f45434343c0d9
Original-Change-Id: I4d93f48d2d01d75a04550d419e023aa42ca95a7a
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/243671
Original-Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/9557
Tested-by: build bot (Jenkins)
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Diffstat (limited to 'src/drivers')
-rw-r--r-- | src/drivers/elog/elog.c | 38 |
1 files changed, 21 insertions, 17 deletions
diff --git a/src/drivers/elog/elog.c b/src/drivers/elog/elog.c index f6b0006..76e8cf7 100644 --- a/src/drivers/elog/elog.c +++ b/src/drivers/elog/elog.c @@ -75,9 +75,13 @@ static elog_event_buffer_state event_buffer_state; static u16 next_event_offset; static u16 event_count; -static int elog_initialized; static struct spi_flash *elog_spi; +static enum { + ELOG_UNINITIALIZED = 0, + ELOG_INITIALIZED, + ELOG_BROKEN, +} elog_initialized = ELOG_UNINITIALIZED; static inline u32 get_rom_size(void) { @@ -522,25 +526,18 @@ int elog_clear(void) static void elog_find_flash(void) { -#if CONFIG_CHROMEOS - u8 *flash_base_ptr; -#endif - elog_debug("elog_find_flash()\n"); #if CONFIG_CHROMEOS /* Find the ELOG base and size in FMAP */ - total_size = find_fmap_entry("RW_ELOG", (void **)&flash_base_ptr); - if (total_size < 0) { - printk(BIOS_WARNING, "ELOG: Unable to find RW_ELOG in FMAP, " - "using CONFIG_ELOG_FLASH_BASE instead\n"); - total_size = CONFIG_ELOG_AREA_SIZE; + u8 *flash_base_ptr; + int fmap_size = find_fmap_entry("RW_ELOG", (void **)&flash_base_ptr); + if (fmap_size < 0) { + printk(BIOS_WARNING, "ELOG: Unable to find RW_ELOG in FMAP\n"); + flash_base = total_size = 0; } else { flash_base = elog_flash_address_to_offset(flash_base_ptr); - - /* Use configured size if smaller than FMAP size */ - if (total_size > CONFIG_ELOG_AREA_SIZE) - total_size = CONFIG_ELOG_AREA_SIZE; + total_size = MIN(fmap_size, CONFIG_ELOG_AREA_SIZE); } #else flash_base = CONFIG_ELOG_FLASH_BASE; @@ -554,8 +551,15 @@ static void elog_find_flash(void) */ int elog_init(void) { - if (elog_initialized) + switch (elog_initialized) { + case ELOG_UNINITIALIZED: + break; + case ELOG_INITIALIZED: return 0; + case ELOG_BROKEN: + return -1; + } + elog_initialized = ELOG_BROKEN; elog_debug("elog_init()\n"); @@ -600,8 +604,6 @@ int elog_init(void) return -1; } - elog_initialized = 1; - printk(BIOS_INFO, "ELOG: FLASH @0x%p [SPI 0x%08x]\n", elog_area, flash_base); @@ -637,6 +639,8 @@ int elog_init(void) #endif #endif + elog_initialized = ELOG_INITIALIZED; + return 0; } |