{
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-11-06",
  "slug": "emmc-pre-eol-information",
  "term": "eMMC PRE_EOL information",
  "aliases": [
    "PRE_EOL_INFO",
    "eMMC pre end-of-life information"
  ],
  "definition": "eMMC PRE_EOL_INFO is an EXT_CSD status field that classifies reserve-block condition as normal, warning or urgent.",
  "note": "EXT_CSD byte 267 encodes undefined as 0x00, normal as 0x01, warning as 0x02 and urgent as 0x03; 0x04-0xFF are reserved. Warning corresponds to 80% reserve-block consumption. [emmc-health-standard]\n\nGeneric eMMC 5.0 reporting separates this status from lifetime A/B estimates; device-specific diagnostics may provide more detail. A reserve-block status must not be substituted for endurance-used percentage. [toradex-health]\n\nNormal is not a guarantee against all failure modes, and an undefined or reserved code is not evidence of a healthy device. Keep the raw status, device identity and observation time when comparing reports.\n\nBKOPS_STATUS is separate: EXT_CSD byte 246, bits 1:0, reports background-operation urgency, with 0x02 indicating performance impact and 0x03 critical work. PRE_EOL 0x03 instead reports urgent reserve-block condition; the matching code does not make the states equivalent. [emmc-health-standard]",
  "related": [
    "emmc",
    "emmc-life-time-estimation",
    "bad-block-management"
  ],
  "citations": [
    {
      "id": "emmc-health-standard",
      "title": "JEDEC JESD84-B51 (February 2015), sections 7.4.22-7.4.24 and 7.4.33, pages 182-183 and 186; TI-hosted copy",
      "url": "https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/791/JESD84_2D00_B51-_2800_1_2900_.pdf",
      "accessed": "2026-11-06"
    },
    {
      "id": "toradex-health",
      "title": "Toradex: eMMC (Linux), generic and vendor-specific health status",
      "url": "https://developer.toradex.com/software/linux-resources/linux-features/emmc-linux/#health-status-as-defined-in-the-emmc-50-standard-onwards",
      "accessed": "2026-11-06"
    },
    {
      "id": "analysis",
      "title": "Hesela: eMMC, UFS and RPMB: interface, boot and security boundaries",
      "url": "https://hesela.com/analyses/emmc-ufs-rpmb-boundaries/",
      "accessed": "2026-11-06"
    }
  ],
  "provenance": [
    "Interpretation is scoped to the cited standard and implementation guidance; no device failure was observed or predicted.",
    "JESD84-B51 table 105 gives no numeric urgent threshold or strict/inclusive comparison; no additional numeric threshold is inferred. [emmc-health-standard]",
    "The limits on healthy-device conclusions are editorial inferences from the status definitions."
  ]
}