Bootstrap - Revision history

Jnc: Clarify cross-compilation

2025-03-21T10:22:20Z

Clarify cross-compilation

← Older revision		Revision as of 10:22, 21 March 2025
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	To '''bootstrap''' (the term can also be used as a noun) means to start a computer-related system from nothing. It has two main meanings:		To '''bootstrap''' (the term can also be used as a noun) means to start a computer-related system from nothing. It has two main meanings:

	The most common is the process of starting a computer as it is powered on. The bootstap is the initial [[object code]] run by the computer, now always held in [[read-only memory\|Read-Only Memory]]. This code usually loads a '''secondary bootstrap''' from [[secondary storage]] into [[main memory]], which then loads and starts the [[operating system]]. Earlier methods for entering the bootstrap code into a blank memory, was special hardware for reading data off an external device such as [[paper tape]], or by manually [[~~Toggle~~ switch\|toggling]] instructions on the [[~~console~~]].		The most common is the process of starting a computer as it is powered on. The bootstap is the initial [[object code]] run by the computer; it is now always held in [[read-only memory\|Read-Only Memory]]. This code usually loads a '''secondary bootstrap''' from [[secondary storage]] into [[main memory]], which then loads and starts the [[operating system]]. Earlier methods for entering the bootstrap code into a blank memory, was special hardware for reading data off an external device such as [[paper tape]], or by manually [[toggle switch\|toggling]] instructions on the [[front panel]].

	The other, less-common meaning, refers to bringing up a [[compiler]] or similar software on a new machine. Given a compiler for language X for machine P, running on P, how do we get a compiler for X for machine Q, running on ~~machine~~ Q? The first step is to modify a copy of the compiler's [[source code]] to emit object code for Q. This is then run through the running compiler for P on P, producing a [[cross-compiler]] for X which runs on P, but produces object code for Q. The modified compiler source is then run through that, thereby producing object code for a compiler which runs on Q, producing object code for Q. This can then be moved to Q, and run there. The first language to pull this trick is reported to have been [[BCPL]].		The other, less-common, meaning refers to bringing up a [[compiler]] or similar software on a new machine. Given a compiler ''in'' language X, ''for'' language X, for machine P, and running on P, how do we get a compiler for X, for machine Q, running on Q? The first step is to modify a copy of the compiler's [[source code]] to emit object code for Q. This is then run through the running compiler for P on P, producing a [[cross-compiler]] for X which runs on P, but produces object code for Q. The modified compiler source is then run through that, thereby producing object code for a compiler which runs on Q, producing object code for Q. This can then be moved to Q, and run there.

			The first language to pull this trick is reported to have been [[BCPL]], which had a compiler written in itself. If the initial compiler is in some '''other'' language (perhaps [[assembly language]] for P), the process is more complicated, but similar.

	[[Category: Computer Basics]]		[[Category: Computer Basics]]

Larsbrinkhoff: Link for "toggling".

2023-08-11T07:08:26Z

Link for "toggling".

← Older revision		Revision as of 07:08, 11 August 2023
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	To '''bootstrap''' (the term can also be used as a noun) means to start a computer-related system from nothing. It has two main meanings:		To '''bootstrap''' (the term can also be used as a noun) means to start a computer-related system from nothing. It has two main meanings:

	The most common is the process of starting a computer as it is powered on. The bootstap is the initial [[object code]] run by the computer, now always held in [[read-only memory\|Read-Only Memory]]. This code usually loads a '''secondary bootstrap''' from [[secondary storage]] into [[main memory]], which then loads and starts the [[operating system]]. Earlier methods for entering the bootstrap code into a blank memory, was special hardware for reading data off an external device such as [[paper tape]], or by manually toggling instructions on the [[console]].		The most common is the process of starting a computer as it is powered on. The bootstap is the initial [[object code]] run by the computer, now always held in [[read-only memory\|Read-Only Memory]]. This code usually loads a '''secondary bootstrap''' from [[secondary storage]] into [[main memory]], which then loads and starts the [[operating system]]. Earlier methods for entering the bootstrap code into a blank memory, was special hardware for reading data off an external device such as [[paper tape]], or by manually [[Toggle switch\|toggling]] instructions on the [[console]].

	The other, less-common meaning, refers to bringing up a [[compiler]] or similar software on a new machine. Given a compiler for language X for machine P, running on P, how do we get a compiler for X for machine Q, running on machine Q? The first step is to modify a copy of the compiler's [[source code]] to emit object code for Q. This is then run through the running compiler for P on P, producing a [[cross-compiler]] for X which runs on P, but produces object code for Q. The modified compiler source is then run through that, thereby producing object code for a compiler which runs on Q, producing object code for Q. This can then be moved to Q, and run there. The first language to pull this trick is reported to have been [[BCPL]].		The other, less-common meaning, refers to bringing up a [[compiler]] or similar software on a new machine. Given a compiler for language X for machine P, running on P, how do we get a compiler for X for machine Q, running on machine Q? The first step is to modify a copy of the compiler's [[source code]] to emit object code for Q. This is then run through the running compiler for P on P, producing a [[cross-compiler]] for X which runs on P, but produces object code for Q. The modified compiler source is then run through that, thereby producing object code for a compiler which runs on Q, producing object code for Q. This can then be moved to Q, and run there. The first language to pull this trick is reported to have been [[BCPL]].

	[[Category: Computer Basics]]		[[Category: Computer Basics]]

Larsbrinkhoff: Bootstrap off paper tape or toggling.

2023-08-11T07:02:40Z

Bootstrap off paper tape or toggling.

← Older revision		Revision as of 07:02, 11 August 2023
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	To '''bootstrap''' (the term can also be used as a noun) means to start a computer-related system from nothing. It has two main meanings:		To '''bootstrap''' (the term can also be used as a noun) means to start a computer-related system from nothing. It has two main meanings:

	The most common is the process of starting a computer as it is powered on. The bootstap is the initial [[object code]] run by the computer, now always held in [[read-only memory\|Read-Only Memory]]. This code usually loads a '''secondary bootstrap''' from [[secondary storage]] into [[main memory]], which then loads and starts the [[operating system]].		The most common is the process of starting a computer as it is powered on. The bootstap is the initial [[object code]] run by the computer, now always held in [[read-only memory\|Read-Only Memory]]. This code usually loads a '''secondary bootstrap''' from [[secondary storage]] into [[main memory]], which then loads and starts the [[operating system]]. Earlier methods for entering the bootstrap code into a blank memory, was special hardware for reading data off an external device such as [[paper tape]], or by manually toggling instructions on the [[console]].

	The other, less-common meaning, refers to bringing up a [[compiler]] or similar software on a new machine. Given a compiler for language X for machine P, running on P, how do we get a compiler for X for machine Q, running on machine Q? The first step is to modify a copy of the compiler's [[source code]] to emit object code for Q. This is then run through the running compiler for P on P, producing a [[cross-compiler]] for X which runs on P, but produces object code for Q. The modified compiler source is then run through that, thereby producing object code for a compiler which runs on Q, producing object code for Q. This can then be moved to Q, and run there. The first language to pull this trick is reported to have been [[BCPL]].		The other, less-common meaning, refers to bringing up a [[compiler]] or similar software on a new machine. Given a compiler for language X for machine P, running on P, how do we get a compiler for X for machine Q, running on machine Q? The first step is to modify a copy of the compiler's [[source code]] to emit object code for Q. This is then run through the running compiler for P on P, producing a [[cross-compiler]] for X which runs on P, but produces object code for Q. The modified compiler source is then run through that, thereby producing object code for a compiler which runs on Q, producing object code for Q. This can then be moved to Q, and run there. The first language to pull this trick is reported to have been [[BCPL]].

	[[Category: Computer Basics]]		[[Category: Computer Basics]]

Jnc: +cat

2018-12-15T23:42:06Z

+cat

← Older revision		Revision as of 23:42, 15 December 2018
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	The other, less-common meaning, refers to bringing up a [[compiler]] or similar software on a new machine. Given a compiler for language X for machine P, running on P, how do we get a compiler for X for machine Q, running on machine Q? The first step is to modify a copy of the compiler's [[source code]] to emit object code for Q. This is then run through the running compiler for P on P, producing a [[cross-compiler]] for X which runs on P, but produces object code for Q. The modified compiler source is then run through that, thereby producing object code for a compiler which runs on Q, producing object code for Q. This can then be moved to Q, and run there. The first language to pull this trick is reported to have been [[BCPL]].		The other, less-common meaning, refers to bringing up a [[compiler]] or similar software on a new machine. Given a compiler for language X for machine P, running on P, how do we get a compiler for X for machine Q, running on machine Q? The first step is to modify a copy of the compiler's [[source code]] to emit object code for Q. This is then run through the running compiler for P on P, producing a [[cross-compiler]] for X which runs on P, but produces object code for Q. The modified compiler source is then run through that, thereby producing object code for a compiler which runs on Q, producing object code for Q. This can then be moved to Q, and run there. The first language to pull this trick is reported to have been [[BCPL]].

			[[Category: Computer Basics]]

Jnc: An OK start

2017-10-30T14:54:18Z

An OK start

New page

To '''bootstrap''' (the term can also be used as a noun) means to start a computer-related system from nothing. It has two main meanings:

The most common is the process of starting a computer as it is powered on. The bootstap is the initial [[object code]] run by the computer, now always held in [[read-only memory|Read-Only Memory]]. This code usually loads a '''secondary bootstrap''' from [[secondary storage]] into [[main memory]], which then loads and starts the [[operating system]].

The other, less-common meaning, refers to bringing up a [[compiler]] or similar software on a new machine. Given a compiler for language X for machine P, running on P, how do we get a compiler for X for machine Q, running on machine Q? The first step is to modify a copy of the compiler's [[source code]] to emit object code for Q. This is then run through the running compiler for P on P, producing a [[cross-compiler]] for X which runs on P, but produces object code for Q. The modified compiler source is then run through that, thereby producing object code for a compiler which runs on Q, producing object code for Q. This can then be moved to Q, and run there. The first language to pull this trick is reported to have been [[BCPL]].