ZXNet эхоконференция «code.zx»

======================================================================== * Forwarded from ZX.SPECTRUM by Kirill Frolov (500:812/9.8). * Originally by: Stas Sergeev (2:5020/3456.28), 22 May 99 02:55. * Originally to: All. ======================================================================== Приветствую тебя, All. Помнится, недавно тут велись споры о существовании сабжа, и было решено, что его нет и быть не может. Так вот, смотрите и удивляйтесь: === Cut === [Logo] The Linux/Microcontroller Project ZILOG Z-80 Port uClinux ported to Z-80 There has been much work by various parties to extend the architectures supported by uClinux, and these have included the MC68EZ328 chipset (widely used in consumer PDAs), and Coldfire, Motorola's next-generation embedded processor line. However, we've been working on some internal projects that pave the way for uClinux to operate on systems with much tougher memory constraints. We're proud to announce the first screen shots of a port of uClinux to the venerable Z-80 processor. This processor, while not especially fast, has been used in a vast array of mass-produced computers, making it a valuable chip to support. Previously, it's been passed over by more mainstream operating systems as being too inefficient or difficult to support. We feel that it is important that Linux be usable whereever possible, so we've spent the time to port uClinux to support the Z-80 platform. We feel this will benefit a wide variety of people, both in the design of new and inexpensive computers, and as a way of providing a useful and stable OS to the many owners of computers already designed around this processor. A technical challenge There were many stumbling blocks for producing this port. The ZILOG Z-80 is relatively old, as processor designs go, and being an 8-bit design is nearly one fourth the speed of modern 32-bit processors. That, and the fact that Z-80 systems were designed back in the days when memory was quite expensive (even ROM, never mind RAM), makes for a very constrained system. We've had to use several innovative approaches, including overlayed kernel loading (using the XOR reduplication technique to store two code pages in every page of ROM) and apply data compression to RAM pages in order to get enough free memory to boot. Despite the challenge, we have succeeded, and would like to show you some of the progress we've made. [Здесь было про TRS-80 Model IV, так что skip] uClinux running on an emulated Sinclair Spectrum Here you can see the tail end of the boot screen of uClinux on an emulated Sinclair Spectrum, using the excellent xzx emulator. I apologize for there not being much detail visible, unfortunately the Spectrum's screen does not lend itself to displaying large amounts of information. Again, as with the TRS-80, there wasn't enough RAM available to start up init and a shell. Adding more RAM should be a bit easier then the TRS-80, although some of the problems unique to the Spectrum (such as the memory extension tending to wobble and fall off) may eventually limit the utility of this platform for running full-scale uClinux applications. [Тут был скриншот. КРУТО!] In times to come... Given the fact that these demonstrations were based on heavily modified emulators (to support the neccessarily large amount of emulated ROM), it will be some time before we can wrap up the changes into something useful that can be released. We estimate that a source code bundle of the Z-80 port will be ready by some time after March 31st, 2000. This planned release will include source patches, the requisite cross-compiler kits, and if the memory requirements are still larger then the average Z-80 systems support, a kit will be supplied including software patches for the common emulators, and designs for hardware modifications to allow booting uClinux on some particular hardware designs, probably including the TRS-80 Model III, and the Sinclair Spectrum/128K. We hope to have ported the Speccy classic Advanced Lawnmower Simulator over to the uClinux/Z-80 OS by then, so that the hardware capabilities of the Sprectrum can be fully appreciated. For more information If you wish to get in touch with the uClinux development team, please send mail to uclinux@RyeHam.ee.ryerson.ca. Kenneth Albanowski and Jeff Dionne are the technical leads, with Michael Durrant providing support. This announcement was written by the fourth member of the team (who, as Kenneth keeps pointing out, doesn't get nearly enough mention) and the only one that can be trusted to write a decent annoucment, Lirpa Loof. 4,155 й Copyright April 1, 1999 The uClinux team === Cut === Hу вот и все. Бывай, All. -+- + Origin: -= Sorry, permanently under construction. =- (2:5020/3456.28) ======================================================================== Hемедленно нажми на RESET, All ! Kirill Frolov. [ZX]