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| 1 | \chapter{Project} |
1 | \chapter{Project} |
| 2 | \label{project} |
2 | \label{project} |
| 3 | 3 | ||
| 4 | The HelenOS project was formed in late October 2004, when the six developers grouped and decided to |
4 | The HelenOS project was formed in late October 2004, when the six |
| - | 5 | developers grouped and decided to adopt previous work of {\JJ} on the |
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| 5 | adopt previous work of {\JJ} on the SPARTAN kernel\footnote{The SPARTAN kernel has been developed |
6 | SPARTAN kernel\footnote{The SPARTAN kernel has been developed by {\JJ} |
| 6 | by {\JJ} since 2001.} as a foundation for their new operating system. |
7 | since 2001.} as a foundation for their new operating system. |
| 7 | 8 | ||
| 8 | The team had then worked on a specification\cite{helenos-spec} until March 8, 2005. The specification |
9 | The team had then worked on a specification\cite{helenos-spec} until |
| - | 10 | March 8, 2005. The specification was based on \MD's draft and |
|
| 9 | was based on \MD's draft and incorporated many suggestions from other members of the team. |
11 | incorporated many suggestions from other members of the team. The |
| 10 | The biggest part of the discussion was concerned about how many and what processor architectures we will support. |
12 | biggest part of the discussion was concerned about how many and what |
| - | 13 | processor architectures we will support. At that time, the SPARTAN |
|
| 11 | At that time, the SPARTAN kernel supported ia32 and mips32 to the extent that kernel threads could be scheduled. |
14 | kernel supported ia32 and mips32 to the extent that kernel threads could |
| 12 | The ia32 port could do some very basic virtual memory operations and was capable of SMP |
15 | be scheduled. The ia32 port could do some very basic virtual memory |
| - | 16 | operations and was capable of SMP service. Moreover, the mips32 port ran |
|
| 13 | service. Moreover, the mips32 port ran only in the msim simulator. We realized the need to support at least |
17 | only in the msim simulator. None of them supported userspace threads. |
| - | 18 | ||
| - | 19 | We realized the need to support at least one 64-bit architecture and |
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| 14 | one 64-bit architecture and have long discussed whether it should be amd64 or ia64. We also considered ppc64. |
20 | have long discussed whether it should be amd64 or ia64. We also considered |
| 15 | At the end, we decided to declare support for three new architectures and five architectures in total, including |
21 | ppc64. At the end, we decided to declare support for three new architectures, |
| - | 22 | five architectures in total. Both amd64 and ia64 made it to the specifications, |
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| - | 23 | as well as PowerPC. As for PowerPC, the specification didn't say whether ppc32 |
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| - | 24 | or ppc64 or both will be supported.\footnote{This has later proven a bit problematic |
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| - | 25 | because it is not very clear what ppc32 should be (i.e. the 32-bit G4 processor is not |
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| 16 | both amd64 and ia64 and also ppc32. |
26 | compatible with the 32-bit mode of the G5 processor.} |
| - | 27 | ||
| - | 28 | It is worth noting that we wanted to be sure of access to respective hardware |
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| - | 29 | or at least simulator, prior to committing to support particular architecture. |
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| - | 30 | The decision to support almost all suggested architectures\footnote{Namely, we didn't declare |
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| - | 31 | support for sparc64, but it got supported anyway as part of \JJ's master thesis.} came after |
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| - | 32 | we had known for sure the above condition was satisfied. |
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| - | 33 | ||
| - | 34 | We constructed our specification so that it contained a well defined |
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| - | 35 | set of mandatory features of the kernel and the userspace layer |
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| - | 36 | that had to be implemented. Besides the mandatory features, there |
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| - | 37 | was also an optional part comprising of three research or experimental |
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| - | 38 | topics. We hoped to eventually find time to work on them. |
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| - | 39 | ||
| - | 40 | After adopting our specification, we started to meet regularily every two weeks |
|
| - | 41 | for the sake of consultations. The regular meetings were cancelled only during |
|
| - | 42 | the exam periods and summer holiday. The first meeting took place on April 28, |
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| - | 43 | April. There had been twenty project meetings before 1.0.0 release. |
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| - | 44 | ||
| - | 45 | The Faculty of Mathematics and Physics officially opened our project on June 10, |
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| - | 46 | 2005. |
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| 17 | 47 | ||