Difference between revisions of "Boot-args (iBoot variable)"

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("rd=md0 nand-enable-reformat=1 -progress" is also used by update ramdisks)
m (rd/rootdev confusion; I don't backlight-level is a boot-arg, only an env variable)
 
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This variable is ignored in firmware >=2.0 when booting to NAND. See also [[Talk:Restore Mode]] These can be booted with a patched iBoot, redsn0w does this when you set custom bootargs.
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These are boot arguments that the iOS [[kernel]] accepts. These can be booted with a patched [[iBoot]]; untethered [[BootROM]] jailbreaks such as [[redsn0w]] and [[checkra1n]] do this when you set custom boot-args.
   
=Known Settings=
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= Known Boot Arguments =
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{| class="wikitable"
* "rd=md0 nand-enable-reformat=1 -progress" (Used in restore and update ramdisks)
 
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|-
* pmd= (used in the [[Ramdisk Hack]])
 
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! boot-arg
* 1 (?)
 
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! Values
* "-v" ([[Verbose boot]])
 
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! Description
* auto-boot (true/false. False does not try to boot the kernelcache)
 
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! Notes
* backlight-level (value from 1 to 128 for backlight level)
 
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|-
* debug=# (# can be replaced with 0x09 for kernel debugging)
 
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| debug=#
* serial=3 (same as [[Debug-uarts (iBoot variable)]])
 
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| <code>0x09</code>: Kernel debugging
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| Set kernel debug options
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|
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|-
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| nand-enable-reformat=#
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| <code>0</code>, <code>1</code>
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| Set whether or not to reformat [[NAND]] when restoring
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| Used when [[Restore Process|restoring]]
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|-
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| pmd=#.#
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| Start/end address of ramdisk
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| Specify a [[Ramdisk|ramdisk]] in memory to boot from
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| Used in the [[Ramdisk Hack]]
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|-
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| -progress
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| {{n/a}}
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| Enable progress bar when restoring
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| Used when [[Restore Process|restoring]]
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|-
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| rd=?
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| <code>'md#'</code>
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| Specify the root device to boot from
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| Used when [[Restore Process|restoring]]; same as <code>rootdev</code>
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|-
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| rootdev=?
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| <code>'md#'</code>
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| Specify the root device to boot from
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| Same as <code>rd</code>
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|-
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| serial=#
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| <code>3</code>: Debug output over serial
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| Set serial debug options
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| Same as <code>[[Debug-uarts (iBoot variable)|debug-uarts]]</code>
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|-
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| -v
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| {{n/a}}
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| Enable verbose booting
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|
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|-
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|}
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= See Also =
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* [[Talk:Restore Mode]]

Latest revision as of 21:15, 9 June 2020

These are boot arguments that the iOS kernel accepts. These can be booted with a patched iBoot; untethered BootROM jailbreaks such as redsn0w and checkra1n do this when you set custom boot-args.

Known Boot Arguments

boot-arg Values Description Notes
debug=# 0x09: Kernel debugging Set kernel debug options
nand-enable-reformat=# 0, 1 Set whether or not to reformat NAND when restoring Used when restoring
pmd=#.# Start/end address of ramdisk Specify a ramdisk in memory to boot from Used in the Ramdisk Hack
-progress N/A Enable progress bar when restoring Used when restoring
rd=? 'md#' Specify the root device to boot from Used when restoring; same as rootdev
rootdev=? 'md#' Specify the root device to boot from Same as rd
serial=# 3: Debug output over serial Set serial debug options Same as debug-uarts
-v N/A Enable verbose booting

See Also