cde947f5f5
Currently we configure uClibc to use kernel headers from "staging" folder with KERNEL_HEADERS="$(STAGING_DIR)/usr/include". This path is added to include search path of uClibc build system in Rules.mak "CFLAGS += -I$(KERNEL_HEADERS)". At the same time on uClibc installation to "staging" we point to the same location "$(STAGING_DIR)/usr" (headers effectively go in "usr/include"). So after every installation to "staging" dependences get touched (even though we copy the same headers every time) and so we may see lots of sources in uClibc get rebuilt. This has 2 consequences: 1. Longer build time - becase even on ordinary buildroot build uClibc is built twice. On "uclibc building" and on "uclibc installation to target". 2. Symbols in libuClibc built initially (that is later installed in "staging/sysroot") are situated with different offset compared to second build (later copied in "target"). This happens because as described above only part of sources get rebuilt and then on final linkage object files are linked in different order. And (2) leads to problems on remote rebugging: gdbserver reports offsets that correspond to pointless assembly in libuClibc on host. Here's how it looks like. Before this patch: $ cd ~/br2_output/i586/target/lib $ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill 423: 0000c42c 54 FUNC GLOBAL DEFAULT 7 kill $ cd ~/br2_output/i586/staging/lib $ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill 423: 0000b518 54 FUNC GLOBAL DEFAULT 7 kill After this patch: $ cd ~/br2_output/i586/target/lib $ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill 423: 0000b518 54 FUNC GLOBAL DEFAULT 7 kill $ cd ~/br2_output/i586/staging/lib $ i586-buildroot-linux-uclibc-readelf -s libuClibc-0.9.33.2.so | grep kill 423: 0000b518 54 FUNC GLOBAL DEFAULT 7 kill Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: Peter Korsgaard <peter@korsgaard.com> Cc: Noam Camus <noamc@ezchip.com> Signed-off-by: Peter Korsgaard <peter@korsgaard.com> |
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arch | ||
board | ||
boot | ||
configs | ||
docs | ||
fs | ||
linux | ||
package | ||
support | ||
system | ||
toolchain | ||
.defconfig | ||
.gitignore | ||
CHANGES | ||
Config.in | ||
Config.in.legacy | ||
COPYING | ||
Makefile | ||
Makefile.legacy | ||
README |
To build and use the buildroot stuff, do the following: 1) run 'make menuconfig' 2) select the packages you wish to compile 3) run 'make' 4) wait while it compiles 5) Use your shiny new root filesystem. Depending on which sort of root filesystem you selected, you may want to loop mount it, chroot into it, nfs mount it on your target device, burn it to flash, or whatever is appropriate for your target system. You do not need to be root to build or run buildroot. Have fun! Offline build: ============== In order to do an offline-build (not connected to the net), fetch all selected source by issuing a $ make source before you disconnect. If your build-host is never connected, then you have to copy buildroot and your toplevel .config to a machine that has an internet-connection and issue "make source" there, then copy the content of your dl/ dir to the build-host. Building out-of-tree: ===================== Buildroot supports building out of tree with a syntax similar to the Linux kernel. To use it, add O=<directory> to the make command line, E.G.: $ make O=/tmp/build And all the output files (including .config) will be located under /tmp/build. More finegrained configuration: =============================== You can specify a config-file for uClibc: $ make UCLIBC_CONFIG_FILE=/my/uClibc.config And you can specify a config-file for busybox: $ make BUSYBOX_CONFIG_FILE=/my/busybox.config To use a non-standard host-compiler (if you do not have 'gcc'), make sure that the compiler is in your PATH and that the library paths are setup properly, if your compiler is built dynamically: $ make HOSTCC=gcc-4.3.orig HOSTCXX=gcc-4.3-mine Depending on your configuration, there are some targets you can use to use menuconfig of certain packages. This includes: $ make HOSTCC=gcc-4.3 linux-menuconfig $ make HOSTCC=gcc-4.3 uclibc-menuconfig $ make HOSTCC=gcc-4.3 busybox-menuconfig Please feed suggestions, bug reports, insults, and bribes back to the buildroot mailing list: buildroot@buildroot.org