1 This is a rough guide to porting Valgrind to a new architecture, or a new 2 operating system. It's quite preliminary, but should get you started. 3 4 [29-May-2005: the stuff about the locations of files is now badly out of 5 date. --njn] 6 7 ----------------------------------------------------------------------------- 8 Porting Valgrind to a new architecture 9 ----------------------------------------------------------------------------- 10 Note that this implies both a new architecture, and a new platform (ie. arch/OS 11 combination). Please add to this list if it is missing anything. 12 13 To begin: 14 15 - Create necessary subdirs (copy x86/ and x86-linux/ subdirs). Yes, even the 16 test subdirectories. (You should make arch-specific tests later to be 17 thorough!) Put in Makefile.am files for them, edit them for the new 18 architecture name. 19 20 - Update configure.in (use x86 and x86-linux as a guide). 21 22 Once it configures ok, get it to compile: 23 24 - Create the Vex guest state type, VexGuest<ARCH>State 25 26 - Copy all the arch-specific and platform-specific files into the new 27 directories, eg. from x86 and x86-linux. Files like (this list is not 28 exhaustive!): 29 30 include/x86/core_arch.h 31 include/x86-linux/core_platform.h 32 coregrind/x86/core_arch.h 33 coregrind/x86-linux/core_platform.h 34 coregrind/x86-linux/vki_arch.h 35 coregrind/x86-linux/vki_arch_posixtypes.h 36 37 Edit obvious things like the file headers, and the #ifdef __X86_TOOL_ARCH_H 38 guards, so they refer to the new architecture, rather than x86. 39 40 Comment all their contents out. 41 42 - Try compiling. When it falls over on missing functions/types/constants, just 43 uncomment and fix up the copied ones. Just use stubs that fail (immediately 44 and obviously! -- use the "I_die_here" macro) for functions and macros to get 45 things compiling. 46 47 For the kernel types, you'll have to copy the types from the kernel source. 48 Use a recent kernel source, please. Don't just pull in all the 49 corresponding types/macros that x86 provides, otherwise you might end up 50 providing more types/macros than the core actually needs; only pull in types 51 as the compiler asks for them. You'll need a lot of the types in 52 vki_arch_posixtypes.h early on. 53 54 You'll need to update the Makefile.am files if you add/remove files. 55 56 Once it compiles ok, get it to run: 57 58 - Try running. When it falls over on stub function/macros, implement them 59 properly. The syscall table and syscall wrappers will be painful; do them 60 individually, on demand. 61 62 - A lot of the arch-specific stuff has been abstracted out of the core, but 63 there undoubtedly remains some arch-specific stuff in there. Abstract it out 64 as necessary, updating the other archs appropriately. 65 66 - If it crashes without telling you why, use lots of diagnostic printfs (or 67 OINKs) to track down the exact location of the crash. 68 69 Once it runs ok: 70 71 - Add the arch to the tests/arch_test.c file so the reg test script will work. 72 (Don't forget to add it to all_archs[].) Likewise for os_test.in and 73 platform_test. 74 75 - Ensure the regression tests work, and add some arch-specific tests to 76 none/tests directory. 77 78 - Add the relevant entries to valgrind.spec.in (copy the x86 and x86-linux 79 ones). 80 81 ----------------------------------------------------------------------------- 82 Porting Valgrind to a new OS 83 ----------------------------------------------------------------------------- 84 Similarly to above, this implies both a new OS, and a new platform. 85 86 - Create necessary subdirs (copy linux/ and x86-linux/ subdirs). 87 88 - Update configure.in (use linux and x86-linux as a guide). 89 90 - Implement all the necessary OS-specific and platform-specific types, 91 functions, and macros... use the following as templates: 92 93 include/linux/core_os.h 94 include/x86-linux/core_platform.h 95 coregrind/linux/core_os.h 96 coregrind/x86-linux/core_platform.h 97 98 - You'll need to copy appropriate kernel types into vki*.h. 99 You'll have to ensure that everywhere that vki_*/VKI_* types and constants 100 are used, that they are suitable for your new OS, otherwise factor their 101 usage out somehow. This will be painful. 102 103 - In particular, you'll need to implement the VGA_(syscall_table). You may be 104 able to reuse some of the generic (eg. POSIX) syscall wrappers, if the types 105 match. Otherwise, you'll have to write your own new wrappers. Do this 106 incrementally, as system calls are hit, otherwise you'll go crazy. 107 108 - Probably lots more things; this list should be added to! 109 110 111
