changeset 1460:876d4849afa1

New FAQ, "why don't your prebuilt binaries work in my ancient root filesystem". Which is more about ancient kernels not having new system calls, really...
author Rob Landley <>
date Thu, 20 Oct 2011 02:05:11 -0500
parents 5c29a091278a
children ad5303b6d35a
files www/FAQ.html
diffstat 1 files changed, 26 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/www/FAQ.html	Thu Oct 20 02:03:48 2011 -0500
+++ b/www/FAQ.html	Thu Oct 20 02:05:11 2011 -0500
@@ -47,6 +47,10 @@
 <li><p><a href=#impactlinux>Q: What happened to</a></p></li>
 <li><p><a href=#android>Q: What if I want to play with android?</a></p></li>
+<li><p><a href=#new_syscalls>Q: Why don't your prebuilt binaries
+work in my ancient system?</a></p></li>
@@ -434,7 +438,8 @@
   # Diff the two and write out the patch to sources/patches
   cd build/packages
-  diff -ruN $PACKAGE $PACKAGE.bak > ../../sources/patches/$PACKAGE-$NAME.patch
+  diff -ruN $PACKAGE $PACKAGE.bak > \
+    ../../sources/patches/$PACKAGE-$NAME.patch
   rm -rf $PACKAGE
   # Run a clean test build
@@ -734,5 +739,25 @@
 <p>You should be able to take it from there.</p>
+<hr /><a name=new_syscalls><h2>Q: Why don't your prebuilt binaries
+work in my ancient system?</h2>
+<p>Linux periodically adds new features, and binaries built using those
+new features may not run on old kernels.  (Linux continues to support old
+binaries, known as "backwards compatability", but does not promise that new
+programs will always run on old systems.)</p>
+<p>For example, powerpc Linux didn't used to have proper socket system calls
+but had to make do with more elaborate/indirect mechanisms.
+<a href=;a=commit;h=86250b9d12caa1>This got fixed</a> during the 2.6.36 development cycle, and
+binaries built against a C library using the newer kernel headers will use
+the new system() syscall as appropriate, resulting in an -ENOSYS error
+on older kernels that doesn't implement the new system call.</p>
+<p>You can use the alternate package mechanism to build against an older
+kernel (such as 2.6.35) and then run ./ static-tools.hdc in
+the resulting system-image-powerpc to get dropbearmulti and busybox binaries
+that restrict themselves to the old system calls.</p>
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