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Merge pull request #2148 from tlaurion/save_t420-hotp-maximized_once_more
config/coreboot-t420-maximized: align defconfig with cleaned defconfig pattern
2 parents 693ae77 + e3db198 commit 420d71e

3 files changed

Lines changed: 132 additions & 13 deletions

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‎config/coreboot-t420-maximized.config‎

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Original file line numberDiff line numberDiff line change
@@ -16,10 +16,9 @@ CONFIG_COMPILER_GCC=y
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# CONFIG_IWYU is not set
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# CONFIG_FMD_GENPARSER is not set
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# CONFIG_UTIL_GENPARSER is not set
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# CONFIG_OPTION_BACKEND_NONE is not set
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CONFIG_USE_OPTION_TABLE=y
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CONFIG_OPTION_BACKEND_NONE=y
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# CONFIG_USE_OPTION_TABLE is not set
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# CONFIG_USE_CBFS_FILE_OPTION_BACKEND is not set
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CONFIG_STATIC_OPTION_TABLE=y
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CONFIG_COMPRESS_RAMSTAGE_LZMA=y
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# CONFIG_COMPRESS_RAMSTAGE_LZ4 is not set
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CONFIG_SEPARATE_ROMSTAGE=y
@@ -348,7 +347,7 @@ CONFIG_NORTHBRIDGE_INTEL_SANDYBRIDGE=y
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# CONFIG_NATIVE_RAMINIT_IGNORE_XMP_MAX_DIMMS is not set
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# CONFIG_NATIVE_RAMINIT_IGNORE_XMP_REQUESTED_VOLTAGE is not set
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# CONFIG_RAMINIT_ALWAYS_ALLOW_DLL_OFF is not set
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CONFIG_RAMINIT_ENABLE_ECC=y
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# CONFIG_RAMINIT_ENABLE_ECC is not set
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CONFIG_IGD_DEFAULT_UMA_SIZE_32MB=y
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# CONFIG_IGD_DEFAULT_UMA_SIZE_64MB is not set
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# CONFIG_IGD_DEFAULT_UMA_SIZE_96MB is not set

‎config/coreboot-t420-maximized.config_defconfig‎

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Original file line numberDiff line numberDiff line change
@@ -1,5 +1,3 @@
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CONFIG_USE_OPTION_TABLE=y
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CONFIG_STATIC_OPTION_TABLE=y
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CONFIG_BOOTSPLASH_IMAGE=y
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CONFIG_BOOTSPLASH_FILE="@BRAND_DIR@/bootsplash.jpg"
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CONFIG_BOOTSPLASH_CONVERT=y
@@ -15,12 +13,14 @@ CONFIG_HAVE_IFD_BIN=y
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CONFIG_BOARD_LENOVO_T420=y
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CONFIG_TPM_MEASURED_BOOT=y
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CONFIG_LINUX_COMMAND_LINE="quiet loglevel=2"
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# CONFIG_RAMINIT_ENABLE_ECC is not set
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# CONFIG_INTEL_CHIPSET_LOCKDOWN is not set
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CONFIG_HAVE_ME_BIN=y
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CONFIG_HAVE_GBE_BIN=y
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CONFIG_GENERIC_LINEAR_FRAMEBUFFER=y
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CONFIG_BOOTSPLASH=y
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CONFIG_DRIVERS_PS2_KEYBOARD=y
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# CONFIG_USE_PC_CMOS_ALTCENTURY is not set
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# CONFIG_DRIVERS_MTK_WIFI is not set
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CONFIG_BOOTMEDIA_LOCK_CONTROLLER=y
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CONFIG_PAYLOAD_LINUX=y

‎doc/variation-to-defconfig.md‎

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@@ -1,16 +1,134 @@
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# Variation to defconfig (cleaned)
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3-
This file lists configuration items found to be inconsistent and/or removed when generating defconfig with `make BOARD=XYZ coreboot.save_in_defconfig_format_in_place` helper for different boards.
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This file lists coreboot Kconfig options found to be inconsistent across
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boards after regenerating defconfigs with `make BOARD=XYZ
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coreboot.save_in_defconfig_format_in_place`. The goal is to document
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which values are "intentional" per-board differences vs. stale defaults
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that should be uniform.
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## CMOS option backend: OPTION_BACKEND_NONE vs USE_OPTION_TABLE
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Coreboot can read configuration values (boot order, debug level, power-on
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behavior, etc.) from either compiled-in defaults or from CMOS NVRAM.
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```
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OPTION_BACKEND_NONE (default in Heads)
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USE_OPTION_TABLE (explicit CMOS option table)
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```
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`OPTION_BACKEND_NONE` means every value comes from the `.config` --
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Heads manages all runtime config through its initrd scripts and TPM
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measured boot, so the coreboot option table is redundant.
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`USE_OPTION_TABLE` means coreboot reads those values from CMOS and the
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cmos.layout / cmos.default files are used at runtime. It also affects
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defaults of related options:
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| Option | Default when OPTION_BACKEND_NONE | Default when USE_OPTION_TABLE=y |
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|---|---|---|
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| `USE_PC_CMOS_ALTCENTURY` | `y` | `n` |
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| `STATIC_OPTION_TABLE` | absent | depends on board |
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**Heads impact:** Neither breaks anything. `OPTION_BACKEND_NONE` is
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preferred since Heads does not rely on coreboot's CMOS option table.
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## Current state audit
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Options are listed with their current count across all
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`config/coreboot-*.config` files and the per-board breakdown.
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### CONFIG_USE_OPTION_TABLE
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Total: **12 `=y`**, **35 `not set`**
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`=y` boards (use CMOS option table):
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`kgpe-d16_server`, `kgpe-d16_server-whiptail`, `kgpe-d16_workstation`,
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`kgpe-d16_workstation-usb_keyboard`, `librem_mini`, `librem_mini_v2`,
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`t430-legacy`, `t430-maximized`, `t530-dgpu-maximized`,
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`w530-dgpu-K1000m-maximized`, `w530-dgpu-K2000m-maximized`,
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`w530-maximized`
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Notable: among Ivy Bridge ThinkPads, T430/T530/W530 use option table but
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x230 does not -- this appears to be a historical artifact, not a
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technical requirement.
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### CONFIG_STATIC_OPTION_TABLE
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Total: **6 `=y`**, **6 `not set`**, rest absent (irrelevant when `USE_OPTION_TABLE=n`)
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Only meaningful when `USE_OPTION_TABLE=y`. `=y` resets CMOS to defaults
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every boot. Present on: `t430-legacy`, `t430-maximized`,
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`t530-dgpu-maximized`, `w530-dgpu-K1000m-maximized`,
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`w530-dgpu-K2000m-maximized`, `w530-maximized`.
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### CONFIG_USE_PC_CMOS_ALTCENTURY
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Writes century byte to CMOS register `0x32` (`RTC_CLK_ALTCENTURY`) and
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reports it in ACPI FADT. Coreboot default is `y` when
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`!USE_OPTION_TABLE`. Help: "May be useful for legacy OSes that assume
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its presence." Heads boots Linux directly which handles century
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internally -- no functional impact either way.
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Total: **29 `=y`**, **18 `not set`**
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`=y` boards (using coreboot default, never explicitly disabled):
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`librem_11`, `librem_13v2`, `librem_13v4`, `librem_14`,
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`librem_15v3`, `librem_15v4`, `librem_l1um_v2`, `m900-maximized`,
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`msi_z690a_ddr4`, `msi_z690a_ddr5`, `msi_z790p_ddr4`,
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`msi_z790p_ddr5`, `optiplex-7019_9010-maximized`,
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`optiplex-7019_9010_TXT-maximized`, `p8z77-m_pro-tpm1`,
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`qemu-tpm1`, `qemu-tpm1-prod`, `qemu-tpm2`, `qemu-tpm2-prod`,
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`t420`, `t440p`, `t480-maximized`, `t480s-maximized`,
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`t520-maximized`, `w541`, `x220`, `x220-maximized`,
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`x230-maximized-fhd_edp`, `z220-cmt`
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`not set` boards (explicitly cleaned):
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`librem_mini`, `librem_mini_v2`, `nitropad-ns50`,
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`novacustom-nv4x_adl`, `novacustom-v540tu`, `novacustom-v560tu`,
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`t420-maximized` *(cleaned 2026-07-01)*, `t430-legacy`,
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`t430-legacy-flash`, `t430-maximized`, `t530-dgpu-maximized`,
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`t530-maximized`, `w530-dgpu-K1000m-maximized`,
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`w530-dgpu-K2000m-maximized`, `w530-maximized`, `x230-legacy`,
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`x230-legacy-flash`, `x230-maximized`
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Note: T430/T530/W530 are `not set` because their `USE_OPTION_TABLE=y`
95+
flips the default to `n` -- they were never explicitly set.
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### CONFIG_RAMINIT_ENABLE_ECC
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Only relevant on Sandy/Ivy Bridge boards using native raminit. Enables
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ECC memory initialization. Most laptop DIMMs are non-ECC, so this is
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typically harmless but useless.
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Total: **14 `=y`**, **7 `not set`**, **34 absent** (non-native-raminit boards)
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`=y` boards:
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`optiplex-7019_9010-maximized`, `optiplex-7019_9010_TXT-maximized`,
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`p8z77-m_pro-tpm1`, `t420`, `t430-maximized`, `t520-maximized`,
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`t530-dgpu-maximized`, `w530-dgpu-K1000m-maximized`,
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`w530-dgpu-K2000m-maximized`, `w530-maximized`, `x220`,
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`x220-maximized`, `x230-maximized-fhd_edp`, `z220-cmt`
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112+
`not set` boards:
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`t420-maximized` *(cleaned 2026-07-01)*, `t430-legacy`,
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`t430-legacy-flash`, `t530-maximized`, `x230-legacy`,
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`x230-legacy-flash`, `x230-maximized`
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### CONFIG_PCI_ALLOW_BUS_MASTER
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Total: nearly all `=y`. Only exception was `x230-maximized` which had
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`not set` -- listed below as a previously removed undesirable.
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## Questionable configs
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8-
These options are inconsistent across boards and should be reviewed.
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Options that appeared in the `make BOARD=XYZ
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coreboot.save_in_defconfig_format_in_place` output and were found to be
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inconsistent across boards.
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### Global
11129

12-
```text
13-
CONFIG_USE_OPTION_TABLE=y
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```
131+
CONFIG_USE_OPTION_TABLE=y # see CMOS option backend section above
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CONFIG_STATIC_OPTION_TABLE=y
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# CONFIG_USE_PC_CMOS_ALTCENTURY is not set
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# CONFIG_DRIVERS_MTK_WIFI is not set
@@ -24,15 +142,17 @@ CONFIG_PCI_ALLOW_BUS_MASTER=y
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#### T480
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27-
```text
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```
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CONFIG_USE_LEGACY_8254_TIMER=y
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```
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## Removed undesirables
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The following lines were removed from specific board defconfig variations. Filenames (when present) are listed above their removed fragments.
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The following lines were removed from specific board defconfig
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variations. Filenames (when present) are listed above their removed
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fragments.
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```text
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```
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config/coreboot-optiplex-7019_9010-maximized.config
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CONFIG_TIMESTAMPS_ON_CONSOLE=y
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config/coreboot-optiplex-7019_9010_TXT-maximized.config

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