Hi, Vincent
On 2025/8/12 00:20, Vincent Li wrote:
Hi Youling,
On Mon, Aug 11, 2025 at 2:28 AM Youling Tang <youling.t...@linux.dev> wrote:
From: Youling Tang <tangyoul...@kylinos.cn>
This patchset implement kexec_file_load() support on LoongArch.
This patch series enables us to load the LoongArch vmlinuz.efi or
vmlinux.efi by specifying its file decriptor, instead of user-filled
buffer via kexec_load() syscall.
To use kexec_file_load() system call, instead of kexec_load(), at kexec
command, '-s' options must be specified. kexec-tools needs to apply the
corresponding patches. These patches can be found in repository [1] and
will be submitted to the kexec-tools community later.
The basic usage of kexec_file is:
1) Load second kernel image:
# kexec -s -l vmlinuz.efi --initrd=initrd.img --reuse-cmdline
2) Startup second kernel:
# kexec -e
For kdump:
1) Load capture kernel image:
# kexec -s -p vmlinuz.efi --initrd=initrd.img --reuse-cmdline
2) Do something to crash, like:
# echo c > /proc/sysrq-trigger
I am new to this feature but I am interested to test this feature, How
do I get the second kernel or capture image vmlinux.efi and
initrd.img, do I need to build them separately and how?
There is no need to build separately. The kernel images and
initrd of the first kernel and the second kernel can be the same
(because LoongArch is a PIE kernel when RELOCATABLE is enabled).
Thanks,
Youling.
Link:
[1] https://github.com/tangyouling/kexec-tools/commits/main/
Youling Tang (6):
LoongArch: Add struct loongarch_image_header for kernel image
LoongArch: Add kexec_file support
LoongArch/kexec_file: Add initrd loading
LoongArch/kexec_file: Add crash dump support
LoongArch/kexec_file: Add "mem" parameter to limit memory usage of
kdump kernel
LoongArch: Enable CONFIG_KEXEC_FILE
arch/loongarch/Kconfig | 8 +
arch/loongarch/configs/loongson3_defconfig | 1 +
arch/loongarch/include/asm/image.h | 58 +++++
arch/loongarch/include/asm/kexec.h | 12 ++
arch/loongarch/kernel/Makefile | 1 +
arch/loongarch/kernel/kexec_image.c | 112 ++++++++++
arch/loongarch/kernel/machine_kexec.c | 33 ++-
arch/loongarch/kernel/machine_kexec_file.c | 234 +++++++++++++++++++++
8 files changed, 448 insertions(+), 11 deletions(-)
create mode 100644 arch/loongarch/include/asm/image.h
create mode 100644 arch/loongarch/kernel/kexec_image.c
create mode 100644 arch/loongarch/kernel/machine_kexec_file.c
--
2.34.1
