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author | Lukas Larsson <lukas@erlang-solutions.com> | 2012-05-23 16:44:25 +0200 |
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committer | Lukas Larsson <lukas@erlang-solutions.com> | 2012-07-19 12:24:40 +0200 |
commit | 6bb1cd1c9595413cdfd9a8875520e1c85e446833 (patch) | |
tree | f0edfcdf63e1f74bfddfb27a776e0f4805e6d97d /HOWTO/BOOTSTRAP.md | |
parent | 4ba364c5df2c574974fb3ec10fe03f2e6ad4f92f (diff) | |
download | otp-6bb1cd1c9595413cdfd9a8875520e1c85e446833.tar.gz otp-6bb1cd1c9595413cdfd9a8875520e1c85e446833.tar.bz2 otp-6bb1cd1c9595413cdfd9a8875520e1c85e446833.zip |
Move README and INSTALL to HOWTO folder
Diffstat (limited to 'HOWTO/BOOTSTRAP.md')
-rw-r--r-- | HOWTO/BOOTSTRAP.md | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/HOWTO/BOOTSTRAP.md b/HOWTO/BOOTSTRAP.md new file mode 100644 index 0000000000..59e31165cf --- /dev/null +++ b/HOWTO/BOOTSTRAP.md @@ -0,0 +1,61 @@ +Notes about prebuilt beam files under version control +===================================================== + +This information applies mostly to developers, some parts only +to developers of the main branch i.e. Ericsson and HiPE personel. + +There are two types of derived code under version control, namely: + +primary bootstrap - Resides in the `$ERL_TOP/bootstrap/{lib,bin}` directories. +preloaded code - Resides in the `$ERL_TOP/erts/preloaded` directory. + +Primary bootstrap +----------------- + +The two types of version controlled code are fundamentally +different. The primary bootstrap is code compiled from source files in +the lib/{kernel,stdlib,compiler} (and header files from +lib/orber/include. They are checked in in the version control system +to make it possible to build directly from the code base tree without +the need for an earlier version of the compiler. When a new version of +OTP is released, these files are updated manually (or rather, by using +the `$ERL_TOP/otp_build` script) and checked in. The files can also be +updated due to changes in the compiler during the development +process. The primary bootstrap is always updated as a separate +deliberate process, never during a normal development build. + +If a prebuilt open source version of erlang is used, the directory +bootstrap initially does not contain any beam files, the directory is +instead populated by copying beam files from the +`$ERL_TOP/lib/{kernel,stdlib,compiler}/ebin` directories. This +construction is to save space in the distribution, but the result +would be the same. Open source developers need not provide patches for +the precompiled beam files in the primary bootstrap, the bootstrap +update is always performed by the main developers. + +Preloaded code +-------------- + +The directory `$ERL_TOP/preloaded` contains both src and ebin +subdirectories. The preloaded code is compiled into the virtual +machine and always present. When compiling the virtual machine, those +beam files need to be present and they are considered a part of the +virtual machine rather than a part of the kernel application. When +preloaded files are to be updated, the source code is built using a +special Makefile in the `$ERL_TOP/preloaded/src` directory, which +creates beam files in the same directory. When they seem to compile +successfully, they can be used in an emulator build by being copied +to the ebin directory. `otp_build update_preloaded` can be used to +ease the process (there are also similar targets in the +`$ERL_TOP/preloaded/src/Makefile`). + +In prebuilt open source distributions, these beam files are also +present, but to update them one might need to change permission on the +`$ERL_TOP/preloaded/ebin` directory, then build and then manually copy +the beam files from the source directory to ../ebin. If patches are +created that involve the source files used to build preloaded code, +always note this specially as the preloaded/ebin directory needs +updating, or provide the new derived files in the patch or as complete +binaries. + +/Patrik, OTP |