Ping
Ross & Richard, is there anything else I need to do for this patch?
Regards,
Qi
-----Original Message-----
From: Chen, Qi
Sent: Thursday, January 9, 2025 9:54 AM
To: Ross Burton <[email protected]>
Cc: [email protected]
Subject: RE: [OE-core][PATCH V2] lib32-64k-pagesize.inc: add conf for building
32bit binary with 64K alignment
Hi Ross,
The "./bsp/marvell-cn10xxx" exists in yocto-kernel-cache's origin/yocto-6.6
branch.
In its master branch, the marvell-cn96xx.cfg also enables
CONFIG_ARM64_64K_PAGES=y.
This patch was tested on pristine poky + qemuarm64. The test steps are in the
commit message. I didn't test all softwares in oe-core, but as
lib32-core-image-full-cmdline started well with no failed systemd service, I
assumed that most softwares should also behave well. I also tested
lib32-sysstat with core-image-minimal.
The help text for ARM64_64K_PAGES changed with this commit:
https://github.com/torvalds/linux/commit/db488be354bc85724d7b9523e94435fdaa761a35
So 32bit arm was not supported at first, but at some point, it was.
Regards,
Qi
-----Original Message-----
From: Ross Burton <[email protected]>
Sent: Thursday, January 9, 2025 1:02 AM
To: Chen, Qi <[email protected]>
Cc: [email protected]
Subject: Re: [OE-core][PATCH V2] lib32-64k-pagesize.inc: add conf for building
32bit binary with 64K alignment
On 25 Dec 2024, at 03:04, Chen Qi via lists.openembedded.org
<[email protected]> wrote:
When 64K page size is enabled, for 32bit multilib, we'll need to build
applications with 64K alignment, otherwise, we'll see errors like below at
runtime:
root@marvell-cn10xxx:~# /lib/ld-linux-armhf.so.3
Segmentation fault
marvell-cn10xxx in yocto-kernel-cache enables CONFIG_ARM64_4K_PAGES=y by
default.
And the issue was first discovered there.
Do you mean _64K_PAGES? Where is this marvell-cn100xxx? In yocto-kernel-cache
there are no users of arm64-64kb-pages and nothing called cn10xxx. Is this a
Wind River-specific fork of yocto-kernel-cache?
However, there's a kernel config fragment in yocto-kernel-cache which
enableds 64K page size for arm64: arch/arm/arm64-64kb-pages.scc. So
it's easy for other
arm64 BSPs to enable this. And when they do so, they'll have problem
with multilib. This patch adds a config file to help people a little
bit in such situation.
The max-page-size option is used to fix this issue. This option is
added to both CFLAGS and LDFLAGS for the purpose of covering as many
recipes as possible.
First, I should point out that changing the page size is an ABI break, and the
32-bit ABI was formalised long before 64kb pages were a thing, so things _will_
break. That said the loader should work, as a decade ago binutils 2.25 changed
the alignment to 64kb pages by default:
https://sourceware.org/git/?p=binutils-gdb.git;a=blobdiff;f=ld/emulparams/armelf_linux.sh;h=280db842208e06e3231ec3a8322369193630a07d;hp=35891f1fc91bddd03677aaefd7146ae5333e6cf0;hb=7572ca8989ead4c3425a1500bc241eaaeffa2c89;hpb=8335d6aa34b88ce31b62e1b578d54ab4aa364435
That won’t help specific pieces of software that eg assume the page size is a
built-time constant (and use the wrong constant), but helloworld should be
good. Can you replicate with pristine poky master and a minimal configuration
in a qemu?
Ross
