diff options
| -rw-r--r-- | src/device/dram/ddr4.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/src/device/dram/ddr4.c b/src/device/dram/ddr4.c index 4f99ecc925..07f9decb74 100644 --- a/src/device/dram/ddr4.c +++ b/src/device/dram/ddr4.c @@ -111,17 +111,31 @@ int spd_decode_ddr4(dimm_attr *dimm, spd_raw_data spd) return SPD_STATUS_INVALID; } - spd_bytes_total = (spd[0] >> 4) & ((1 << 3) - 1); - spd_bytes_used = spd[0] & ((1 << 4) - 1); + spd_bytes_total = (spd[0] >> 4) & 0x7; + spd_bytes_used = spd[0] & 0xf; if (!spd_bytes_total || !spd_bytes_used) { printk(BIOS_ERR, "SPD failed basic sanity checks\n"); return SPD_STATUS_INVALID; } + if (spd_bytes_total >= 3) + printk(BIOS_WARNING, "SPD Bytes Total value is reserved\n"); + spd_bytes_total = 256 << (spd_bytes_total - 1); + + if (spd_bytes_used > 4) { + printk(BIOS_ERR, "SPD Bytes Used value is reserved\n"); + return SPD_STATUS_INVALID; + } + spd_bytes_used = spd_bytes_used_table[spd_bytes_used]; + if (spd_bytes_used > spd_bytes_total) { + printk(BIOS_ERR, "SPD Bytes Used is greater than SPD Bytes Total\n"); + return SPD_STATUS_INVALID; + } + /* Verify CRC of blocks that have them, do not step over 'used' length */ for (int i = 0; i < ARRAY_SIZE(spd_blocks); i++) { /* this block is not checksumed */ |