From 6581ceaad5ded8a721fb5758a70777f8310eb7e6 Mon Sep 17 00:00:00 2001 From: Rob Landley Date: Mon, 9 Jan 2023 01:08:41 -0600 Subject: [PATCH] Update FAQ a bit. --- www/faq.html | 44 +++++++++++++++++++++++++++++--------------- 1 file changed, 29 insertions(+), 15 deletions(-) diff --git a/www/faq.html b/www/faq.html index 742509c6..6026179a 100755 --- a/www/faq.html +++ b/www/faq.html @@ -548,17 +548,21 @@ export "PATH=~/musl-cross-make/ccc/m68k-linux-musl-cross/bin:$PATH"
LDFLAGS=--static CROSS_COMPILE=m68k-linux-musl- make distclean defconfig toybox

-

(Both of those examples use static linking so you can install just +

Both of those examples use static linking so you can install just the single file to target, or test them with "qemu-m68k toybox". Feel free to dynamically link instead if you prefer, mkroot offers a "dynamic" add-on to copy the compiler's shared libraries into the new root -filesystem.)

+filesystem.

+ +

Although you can individually override $CC and $STRIP and such, +providing the prefix twice applies it twice, ala +"CROSS_COMPILE=prefix- CC=prefix-cc" gives "prefix-prefix-cc".

Toybox's system builder can use a simpler $CROSS -variable to specify the target(s) to build for if you've installed +variable to specify the target name(s) to build for if you've installed compatible cross compilers under the "ccc" directory. -Behind the scenes this uses wildcard expansion to set $CROSS_COMPILER to -an appropriate path/prefix-.

+Behind the scenes this uses wildcard expansion to set $CROSS_COMPILE to +an appropriate "path/prefix-".

Q: What architectures does toybox support?

@@ -717,7 +721,9 @@ Pages.

Booting a simple system to a shell prompt requires a kernel to drive the hardware (such as Linux, or BSD with a Linux emulation layer), programs for the system to run (such as toybox's commands), and a C library ("libc") to connect them together.

Toybox has a policy of requiring no external dependencies other than the -kernel and C library (at least for defconfig builds). You can optionally enable support for +kernel and C library (at least for defconfig builds). Our "software bill +of materials" (SBOM) defaults to just "the C library", both at build time +and and runtime. You can optionally enable support for additional libraries in menuconfig (such as openssl, zlib, or selinux), but toybox either provides its own built-in versions of such functionality (which the libraries provide larger, more complex, often assembly optimized @@ -757,12 +763,16 @@ auditable version of the cmdline portion of that base.

root". To enter the resulting root filesystem, "sudo chroot root/host/fs /init". Type "exit" to get back out.

-

You can cross compile simple three package (toybox+libc+linux) -systems configured to boot to a shell prompt under the emulator -qemu -by specifying a target type with CROSS= -(or by setting CROSS_COMPILE= to a cross compiler prefix with optional absolute -path), and pointing the build at a Linux kernel source directory, ala:

+

Prebuilt binary versions of these system images, suitable for running +under the emulator qemu, are uploaded to +the website +each release if you'd like to try before building from source.

+ +

You can cross compile simple three package (toybox+libc+linux) systems +configured to boot to a shell prompt under qemu by setting CROSS_COMPILE= to a +cross compiler prefix (or by installing cross compilers +in the "ccc" subdirectory and specifying a target type with CROSS=) +and also pointing the build at a Linux kernel source directory, ala:

make root CROSS=sh4 LINUX=~/linux

@@ -778,11 +788,15 @@ this system because 1) you're in a toybox source directory, 2) your cross compiler has a libc built into it, 3) you tell it where to find a Linux kernel source directory with LINUX= on the command line. If you don't say LINUX=, it skips that part of the build and just produces a root filesystem directory -ala the first example in this FAQ answer.

+(root/$CROSS/fs or root/host/fs if no $CROSS target specified), which you +can chroot into if your architecture can run those binaries. (For PID other +than 1, the /init script at the top of the directory sets up and cleans up +the /proc mount points, so chroot root/i686/fs /init is a reasonable +"poke around and look at things" smoketest.)

The CROSS= shortcut expects a "ccc" symlink in the toybox source directory -pointing at a directory full of cross compilers. The ones I test this with are built from the musl-libc -maintainer's +pointing at a directory full of cross compilers. The ones I test this with are +built from the musl-libc maintainer's musl-cross-make project, built by running toybox's scripts/mcm-buildall.sh in a musl-cross-make checkout directory, -- 2.39.2