openwrt/target/linux/gemini/patches-4.19/0011-ARM-dts-Fix-up-SQ201-flash-access.patch
Linus Walleij dc451a4b24 gemini: Enable flash boot on reference design type
The flash layout on the Storlink reference design for Gemini
is using 2 MB flash for the kernel, and it also insists on
overwriting the partition table with default values on every
boot. The same is true for the SQ201. This poses a problem
on recent OpenWrt firmware as the base zImage is bigger
than 2 MB.

At the same time there is a ramdisk partition of 6 MB that we
don't really need. The partition table looks like this:

Creating 7 MTD partitions on "30000000.flash":
0x000000000000-0x000000016000 : "BOOT"
0x000000120000-0x000000320000 : "Kern"
0x000000320000-0x000000920000 : "Ramdisk"
0x000000920000-0x000000f20000 : "Application"
0x000000f20000-0x000000f40000 : "VCTL"
0x000000f40000-0x000000fe0000 : "CurConf"
0x000000fe0000-0x000001000000 : "FIS directory"

On boot the "Kern" partition is copied to RAM @0x01600000
and the "Ramdisk" partition is copied to RAM @0x00800000.
Then the kernel is executed.

The idea with this patch is to extend the "Kern" partition
with the "Ramdisk" partition to get a full 8 MB to use
for the kernel. Then we put the OpenWrt JFFS2 rootfs
inside the "Application" partition.

We create a small assembly loop that we prepend to the
"Kern" image that will copy the "Kern" from 0x0160000
and the "Ramdisk" from 0x00800000 and put them in
consecutive space at 0x00400000 and execute it from
there, using "Application" as rootfs.

We generate 3 main files:
- zImage - contains the assembly bootstrap loop and
  the first part of the generated kernel image
- rd.gz - contains the second part of the generated
  kernel image
- hddapp.tgz - contains the root filesystem

On the SQ201 I flash these manually using the native boot
loader PLATO, "Y" alternative for the zImage, "R" for
the rd.gz image and "A" for hddapp.tgz.

This works fine and I can now boot to prompt on the SQ201
with nothing but flash.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-08-17 16:57:32 +02:00

69 lines
1.8 KiB
Diff

From 186692e51e6c40d8ebd05d25f009098eb00f8110 Mon Sep 17 00:00:00 2001
From: Linus Walleij <linus.walleij@linaro.org>
Date: Fri, 19 Oct 2018 09:00:51 +0200
Subject: [PATCH 11/18] ARM: dts: Fix up SQ201 flash access
This sets the partition information on the SQ201 to be read
out from the RedBoot partition table, removes the static
partition table and sets our boot options to mount root from
/dev/mtdblock2 where the initramfs resides.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
arch/arm/boot/dts/gemini-sq201.dts | 37 ++++--------------------------
1 file changed, 5 insertions(+), 32 deletions(-)
--- a/arch/arm/boot/dts/gemini-sq201.dts
+++ b/arch/arm/boot/dts/gemini-sq201.dts
@@ -20,7 +20,7 @@
};
chosen {
- bootargs = "console=ttyS0,115200n8 root=/dev/sda1 rw rootwait";
+ bootargs = "console=ttyS0,115200n8 root=/dev/mtdblock3 rw rootfstype=squashfs,jffs2 rootwait";
stdout-path = &uart0;
};
@@ -131,37 +131,10 @@
/* 16MB of flash */
reg = <0x30000000 0x01000000>;
- partition@0 {
- label = "RedBoot";
- reg = <0x00000000 0x00120000>;
- read-only;
- };
- partition@120000 {
- label = "Kernel";
- reg = <0x00120000 0x00200000>;
- };
- partition@320000 {
- label = "Ramdisk";
- reg = <0x00320000 0x00600000>;
- };
- partition@920000 {
- label = "Application";
- reg = <0x00920000 0x00600000>;
- };
- partition@f20000 {
- label = "VCTL";
- reg = <0x00f20000 0x00020000>;
- read-only;
- };
- partition@f40000 {
- label = "CurConf";
- reg = <0x00f40000 0x000a0000>;
- read-only;
- };
- partition@fe0000 {
- label = "FIS directory";
- reg = <0x00fe0000 0x00020000>;
- read-only;
+ partitions {
+ compatible = "redboot-fis";
+ /* Eraseblock at 0xfe0000 */
+ fis-index-block = <0x1fc>;
};
};