From 97158fe10e6090a8b21629df130734bac53f87ee Mon Sep 17 00:00:00 2001
From: Hannu Nyman <hannu.nyman@iki.fi>
Date: Wed, 9 Feb 2022 23:54:47 +0200
Subject: kernel: package ramoops pstore-ram crash log storage

Package the ability to log kernel crashes to 'ramoops' pstore
files into RAM in /sys/fs/pstore

Reference to the ramoops admin guide in upstream Linux:
https://www.kernel.org/doc/html/v5.10/admin-guide/ramoops.html

The files in RAM survive a warm reboot, but not a cold reboot.

Note: kmod-ramoops selects kmod-pstore and kmod-reed-solomon.

The feature can be used by selecting the kmod-ramoops and
adding a ramoops reserved-memory definition to the device DTS.
Example from R7800:

       reserved-memory {
                rsvd@5fe00000 {
                        reg = <0x5fe00000 0x200000>;
                        reusable;
                };

                ramoops@42100000 {
                        compatible = "ramoops";
                        reg = <0x42100000 0x40000>;
                        record-size = <0x4000>;
                        console-size = <0x4000>;
                        ftrace-size = <0x4000>;
                        pmsg-size = <0x4000>;
                };
        };

If no definition has been made in DTS, no crash log is stored
for the device.

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
(added CONFIG_EFI_VARS_PSTORE disable)
---
 package/kernel/linux/modules/fs.mk    | 21 +++++++++++++++++++++
 package/kernel/linux/modules/other.mk | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

(limited to 'package/kernel')

diff --git a/package/kernel/linux/modules/fs.mk b/package/kernel/linux/modules/fs.mk
index b6d2a120d4..91cf1ea233 100644
--- a/package/kernel/linux/modules/fs.mk
+++ b/package/kernel/linux/modules/fs.mk
@@ -498,6 +498,27 @@ endef
 $(eval $(call KernelPackage,fs-ntfs))
 
 
+define KernelPackage/pstore
+  SUBMENU:=$(FS_MENU)
+  TITLE:=Pstore file system
+  DEFAULT:=m if ALL_KMODS
+  KCONFIG:= \
+	CONFIG_PSTORE \
+	CONFIG_PSTORE_COMPRESS=y \
+	CONFIG_PSTORE_COMPRESS_DEFAULT="deflate" \
+	CONFIG_PSTORE_DEFLATE_COMPRESS=y \
+	CONFIG_PSTORE_DEFLATE_COMPRESS_DEFAULT=y
+  FILES:= $(LINUX_DIR)/fs/pstore/pstore.ko
+  AUTOLOAD:=$(call AutoLoad,30,pstore,1)
+endef
+
+define KernelPackage/pstore/description
+ Kernel module for pstore filesystem support
+endef
+
+$(eval $(call KernelPackage,pstore))
+
+
 define KernelPackage/fs-reiserfs
   SUBMENU:=$(FS_MENU)
   TITLE:=ReiserFS filesystem support
diff --git a/package/kernel/linux/modules/other.mk b/package/kernel/linux/modules/other.mk
index f712c95c8e..5ccc860790 100644
--- a/package/kernel/linux/modules/other.mk
+++ b/package/kernel/linux/modules/other.mk
@@ -770,6 +770,41 @@ endef
 $(eval $(call KernelPackage,mtdram))
 
 
+define KernelPackage/ramoops
+  SUBMENU:=$(OTHER_MENU)
+  TITLE:=Ramoops (pstore-ram)
+  DEFAULT:=m if ALL_KMODS
+  KCONFIG:=CONFIG_PSTORE_RAM
+  DEPENDS:=+kmod-pstore +kmod-reed-solomon
+  FILES:= $(LINUX_DIR)/fs/pstore/ramoops.ko
+  AUTOLOAD:=$(call AutoLoad,30,ramoops,1)
+endef
+
+define KernelPackage/ramoops/description
+ Kernel module for pstore-ram (ramoops) crash log storage
+endef
+
+$(eval $(call KernelPackage,ramoops))
+
+
+define KernelPackage/reed-solomon
+  SUBMENU:=$(OTHER_MENU)
+  TITLE:=Reed-Solomon error correction
+  DEFAULT:=m if ALL_KMODS
+  KCONFIG:=CONFIG_REED_SOLOMON \
+	CONFIG_REED_SOLOMON_DEC8=y \
+	CONFIG_REED_SOLOMON_ENC8=y
+  FILES:= $(LINUX_DIR)/lib/reed_solomon/reed_solomon.ko
+  AUTOLOAD:=$(call AutoLoad,30,reed_solomon,1)
+endef
+
+define KernelPackage/reed-solomon/description
+ Kernel module for Reed-Solomon error correction
+endef
+
+$(eval $(call KernelPackage,reed-solomon))
+
+
 define KernelPackage/serial-8250
   SUBMENU:=$(OTHER_MENU)
   TITLE:=8250 UARTs
-- 
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