Comments on: Secret instruction sets about to make a come-back http://shape-of-code.coding-guidelines.com/2010/01/28/secret-instruction-sets-about-to-make-a-come-back/ Sun, 12 Feb 2012 22:01:48 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: The Shape of Code » Designing a processor for increased source portability costs http://shape-of-code.coding-guidelines.com/2010/01/28/secret-instruction-sets-about-to-make-a-come-back/comment-page-1/#comment-1448 The Shape of Code » Designing a processor for increased source portability costs Tue, 09 Feb 2010 02:29:16 +0000 http://shape-of-code.coding-guidelines.com/?p=173#comment-1448 [...] vendor make it difficult for developers to port open source applications to their proprietary cpu? Keeping the instruction set secret is one technique, another is to design a cpu that breaks often relied upon assumptions that [...] [...] vendor make it difficult for developers to port open source applications to their proprietary cpu? Keeping the instruction set secret is one technique, another is to design a cpu that breaks often relied upon assumptions that [...]

]]> By: Derek-Jones http://shape-of-code.coding-guidelines.com/2010/01/28/secret-instruction-sets-about-to-make-a-come-back/comment-page-1/#comment-1128 Derek-Jones Fri, 29 Jan 2010 12:26:34 +0000 http://shape-of-code.coding-guidelines.com/?p=173#comment-1128 I don't believe that the 'many eyes' theory of fault finding (or instruction reverse engineering) holds much water. Most people don' have the skill, inclination or time to get involved. Over time information on any secret instruction set will leak out. It only takes one skilled person with the inclination and time, or somebody to leak a confidential document. But once sufficient information is available who will write the code generator? Again given time I'm sure one or more people will write one. However, Apple's lawyers will ensure that getting hold of this compiler will be hard (assuming Apple want to keep the instruction set secret), so bugs will probably take ages to be fixed and the quality probably low. Any commercial company will not touch a 'black market' compiler and will have to strike a deal with Apple to port their application, which means Apple maintains control of the money making (the whole purpose of the exercise).. I don’t believe that the ‘many eyes’ theory of fault finding (or instruction reverse engineering) holds much water. Most people don’ have the skill, inclination or time to get involved.

Over time information on any secret instruction set will leak out. It only takes one skilled person with the inclination and time, or somebody to leak a confidential document. But once sufficient information is available who will write the code generator? Again given time I’m sure one or more people will write one. However, Apple’s lawyers will ensure that getting hold of this compiler will be hard (assuming Apple want to keep the instruction set secret), so bugs will probably take ages to be fixed and the quality probably low.

Any commercial company will not touch a ‘black market’ compiler and will have to strike a deal with Apple to port their application, which means Apple maintains control of the money making (the whole purpose of the exercise)..

]]> By: Stephen Parker http://shape-of-code.coding-guidelines.com/2010/01/28/secret-instruction-sets-about-to-make-a-come-back/comment-page-1/#comment-1126 Stephen Parker Fri, 29 Jan 2010 07:08:43 +0000 http://shape-of-code.coding-guidelines.com/?p=173#comment-1126 This seems unlikely. The A4 will be an ARM Cortex plus peripherals. There are too many iPhone OS developers out there for any specialised instruction set to remain secret. This seems unlikely. The A4 will be an ARM Cortex plus peripherals. There are too many iPhone OS developers out there for any specialised instruction set to remain secret.

]]> By: Twitter Trackbacks for The Shape of Code » Secret instruction sets about to make a come-back [coding-guidelines.com] on Topsy.com http://shape-of-code.coding-guidelines.com/2010/01/28/secret-instruction-sets-about-to-make-a-come-back/comment-page-1/#comment-1123 Twitter Trackbacks for The Shape of Code » Secret instruction sets about to make a come-back [coding-guidelines.com] on Topsy.com Fri, 29 Jan 2010 05:23:40 +0000 http://shape-of-code.coding-guidelines.com/?p=173#comment-1123 [...] The Shape of Code » Secret instruction sets about to make a come-back shape-of-code.coding-guidelines.com/2010/01/secret-instruction-sets-about-to-make-a-come-back – view page – cached Home > Uncategorized > Secret instruction sets about to make a come-back [...] [...] The Shape of Code » Secret instruction sets about to make a come-back shape-of-code.coding-guidelines.com/2010/01/secret-instruction-sets-about-to-make-a-come-back – view page – cached Home > Uncategorized > Secret instruction sets about to make a come-back [...]

]]> By: The Shape of Code » Minimum information needed for writing a code generator http://shape-of-code.coding-guidelines.com/2010/01/28/secret-instruction-sets-about-to-make-a-come-back/comment-page-1/#comment-1116 The Shape of Code » Minimum information needed for writing a code generator Fri, 29 Jan 2010 00:12:13 +0000 http://shape-of-code.coding-guidelines.com/?p=173#comment-1116 [...] a compiler writer is faced with writing a back-end for an undocumented processor, what is the minimum amount of information that needs to be reverse [...] [...] a compiler writer is faced with writing a back-end for an undocumented processor, what is the minimum amount of information that needs to be reverse [...]

]]> By: Derek-Jones http://shape-of-code.coding-guidelines.com/2010/01/28/secret-instruction-sets-about-to-make-a-come-back/comment-page-1/#comment-1107 Derek-Jones Thu, 28 Jan 2010 11:35:31 +0000 http://shape-of-code.coding-guidelines.com/?p=173#comment-1107 There are advantages for Apple to take an existing design and tweak it for their own requirement (e.g., lower cost, proven design). The A4 instruction set does not need to be completely unknown to meet a lock-out objective. The semiconductor company purchased by Apple a couple of years ago, PA Semi, used to specialised in low power POWER/PowerPC designs and I would think that this is a more likely choice if they go down a tweak an existing processor route. There are advantages for Apple to take an existing design and tweak it for their own requirement (e.g., lower cost, proven design). The A4 instruction set does not need to be completely unknown to meet a lock-out objective. The semiconductor company purchased by Apple a couple of years ago, PA Semi, used to specialised in low power POWER/PowerPC designs and I would think that this is a more likely choice if they go down a tweak an existing processor route.

]]> By: Tony Finch http://shape-of-code.coding-guidelines.com/2010/01/28/secret-instruction-sets-about-to-make-a-come-back/comment-page-1/#comment-1106 Tony Finch Thu, 28 Jan 2010 08:24:15 +0000 http://shape-of-code.coding-guidelines.com/?p=173#comment-1106 Most commentators think the A4 is an ARM system-on-chip. There's unlikely to be anythijng proprietory about the CPU instruction set. However the GPU is more likely to be kept proproietory - but this is also true for mainstream x86 desktops and laptops. Most commentators think the A4 is an ARM system-on-chip. There’s unlikely to be anythijng proprietory about the CPU instruction set. However the GPU is more likely to be kept proproietory – but this is also true for mainstream x86 desktops and laptops.

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