diff options
| -rw-r--r-- | src/cpu/samsung/exynos5250/dmc.h | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/src/cpu/samsung/exynos5250/dmc.h b/src/cpu/samsung/exynos5250/dmc.h index d1dfbb162f..b778e099d8 100644 --- a/src/cpu/samsung/exynos5250/dmc.h +++ b/src/cpu/samsung/exynos5250/dmc.h @@ -152,12 +152,27 @@ enum ddr_mode { DDR_MODE_COUNT, }; +/* For reasons unknown, people are in the habit of taking a 32-bit + * field with 2 possible values and packing it with, say, 2 bits. A + * non-robust encoding, using only 2 bits of a 32-bit field, is + * incredibly difficult to deal with when things go wrong, because + * there are a lot of things that get expressed as 0, 1, or 2. If + * you're scanning with jtag or dumping memory it is really hard to + * tell when you've hit the beginning of the struct. So, let's be a + * bit smart here. First, while it's common to let the enum count + * entries for you, when there are two of them, we can do the + * counting. And, let's set the values to something we can easily scan + * for in memory. Since '1' and '2' are rather common, we pick + * something that's actually of some value when things go wrong. This + * setup motivated by a use case: something's going wrong and having a + * manuf name of '1' or '2' is completely useless! + */ enum mem_manuf { MEM_MANUF_AUTODETECT, - MEM_MANUF_ELPIDA, - MEM_MANUF_SAMSUNG, + MEM_MANUF_ELPIDA = 0xe7b1da, + MEM_MANUF_SAMSUNG = 0x5a5096, - MEM_MANUF_COUNT, + MEM_MANUF_COUNT = 2, // fancy that. }; /* CONCONTROL register fields */ |