25 lines
1.0 KiB
Markdown
25 lines
1.0 KiB
Markdown
SYNOPSIS
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System Five Import Libraries
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OVERVIEW
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Bell System Five is the umbrella term we use to describe Linux,
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FreeBSD, OpenBSD, and Mac OS X which all have nearly-identical
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application binary interfaces that stood the test of time, having
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definitions nearly the same as those of AT&T back in the 1980's.
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Cosmopolitan aims to help you build apps that can endure over the
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course of decades, just like these systems have: without needing to
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lift a finger for maintenance churn, broken builds, broken hearts.
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The challenge to System V binary compatibility basically boils down
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to numbers. All these systems agree on what services are provided,
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but tend to grant them wildly different numbers.
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We address this by putting all the numbers in a couple big shell
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scripts, ask the GNU Assembler to encode them into binaries using an
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efficient LEB128 encoding, unpacked by _init(), and ref'd via extern
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const. It gives us good debuggability, and any costs are gained back
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by fewer branches in wrapper functions.z
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