1*eeb7b415SFrans KaashoekNOTE: we have stopped maintaining the x86 version of xv6, and switched 2*eeb7b415SFrans Kaashoekour efforts to the RISC-V version 3*eeb7b415SFrans Kaashoek(https://github.com/mit-pdos/xv6-riscv.git) 4*eeb7b415SFrans Kaashoek 582537b71Srtmxv6 is a re-implementation of Dennis Ritchie's and Ken Thompson's Unix 682537b71SrtmVersion 6 (v6). xv6 loosely follows the structure and style of v6, 782537b71Srtmbut is implemented for a modern x86-based multiprocessor using ANSI C. 8b52151e0Skaashoek 9bc54fa39SrtmACKNOWLEDGMENTS 102e898063Skaashoek 11f0400600Srscxv6 is inspired by John Lions's Commentary on UNIX 6th Edition (Peer 1282537b71Srtmto Peer Communications; ISBN: 1-57398-013-7; 1st edition (June 14, 13b818915fSFrans Kaashoek2000)). See also https://pdos.csail.mit.edu/6.828/, which 1482537b71Srtmprovides pointers to on-line resources for v6. 15b52151e0Skaashoek 1682537b71Srtmxv6 borrows code from the following sources: 1782537b71Srtm JOS (asm.h, elf.h, mmu.h, bootasm.S, ide.c, console.c, and others) 1882bb0b56SAustin Clements Plan 9 (entryother.S, mp.h, mp.c, lapic.c) 19801affcdSkaashoek FreeBSD (ioapic.c) 2082537b71Srtm NetBSD (console.c) 21801affcdSkaashoek 225bf3fbeeSFrans KaashoekThe following people have made contributions: Russ Cox (context switching, 235bf3fbeeSFrans Kaashoeklocking), Cliff Frey (MP), Xiao Yu (MP), Nickolai Zeldovich, and Austin 245bf3fbeeSFrans KaashoekClements. 25801affcdSkaashoek 265bf3fbeeSFrans KaashoekWe are also grateful for the bug reports and patches contributed by Silas 27f3048879SFrans KaashoekBoyd-Wickizer, Anton Burtsev, Cody Cutler, Mike CAT, Tej Chajed, eyalz800, 28f3048879SFrans KaashoekNelson Elhage, Saar Ettinger, Alice Ferrazzi, Nathaniel Filardo, Peter 29f3048879SFrans KaashoekFroehlich, Yakir Goaron,Shivam Handa, Bryan Henry, Jim Huang, Alexander 30f3048879SFrans KaashoekKapshuk, Anders Kaseorg, kehao95, Wolfgang Keller, Eddie Kohler, Austin 31b818915fSFrans KaashoekLiew, Imbar Marinescu, Yandong Mao, Matan Shabtay, Hitoshi Mitake, Carmi 32f3048879SFrans KaashoekMerimovich, Mark Morrissey, mtasm, Joel Nider, Greg Price, Ayan Shafqat, 33f3048879SFrans KaashoekEldar Sehayek, Yongming Shen, Cam Tenny, tyfkda, Rafael Ubal, Warren 34f3048879SFrans KaashoekToomey, Stephen Tu, Pablo Ventura, Xi Wang, Keiichi Watanabe, Nicolas 35f3048879SFrans KaashoekWolovick, wxdao, Grant Wu, Jindong Zhang, Icenowy Zheng, and Zou Chang Wei. 367b814133SAustin Clements 37fa1b3410SrscThe code in the files that constitute xv6 is 38b2ca8e3eSFrans KaashoekCopyright 2006-2018 Frans Kaashoek, Robert Morris, and Russ Cox. 392e898063Skaashoek 402e898063SkaashoekERROR REPORTS 412e898063Skaashoek 42*eeb7b415SFrans KaashoekWe don't process error reports (see note on top of this file). 43641e29c5Skaashoek 44bc54fa39SrtmBUILDING AND RUNNING XV6 454d33ef86Srsc 464638cabfSRobert MorrisTo build xv6 on an x86 ELF machine (like Linux or FreeBSD), run 474638cabfSRobert Morris"make". On non-x86 or non-ELF machines (like OS X, even on x86), you 484638cabfSRobert Morriswill need to install a cross-compiler gcc suite capable of producing 49b818915fSFrans Kaashoekx86 ELF binaries (see https://pdos.csail.mit.edu/6.828/). 504638cabfSRobert MorrisThen run "make TOOLPREFIX=i386-jos-elf-". Now install the QEMU PC 514638cabfSRobert Morrissimulator and run "make qemu".