RK3588雙系統啟動流程如下圖

uboot根據按鍵來識別要啟動的系統，這里可以使用撥碼開關來代替。

uboot在加載分區的時根據分區名字來區分加載android或者linux的分區，所以在linux和android分區表中需要用"_android"字段來區分。

硬件環境

基于RK3588 EVB1

開發板

實現，系統切換按鍵是ESC 返回鍵

軟件環境

RK3588 Android12 SDK + RK3588 linux Debian系統

要求

Android和linux的固件的代碼uboot和rkbin部分需要一致，因為uboot和loader是共用一份

uboot需要額外補丁，可以通過RK的redmine獲取

代碼修改

uboot引導不同的系統

在uboot打上支持雙系統的補丁0003-disk-part-Support-get-par

ti

tion-name-suffix-from-env.patch，該補丁可以通過RK的redmine系統獲取。

設置切換按鍵及分區名稱下標

u-boot$

//配置BACK按鍵做為切換按鍵，這里使用adc采樣，設置按鍵對應的adc值

diff --git a/arch/arm/dts/rk3588-evb.dts b/arch/arm/dts/rk3588-evb.dts

index ad750d5b74..b6218fd742 100644

--- a/arch/arm/dts/rk3588-evb.dts

+++ b/arch/arm/dts/rk3588-evb.dts

@@

-27,5 +27,12 @@

label = "volume up";

press-threshold-microvolt = <1750>;

};

+

+ back-key {

+ u-boot,dm-pre-reloc;

+ linux,code =

;

+ label = "back";

+ press-threshold-microvolt = <1235000>;

+ };

};

};

//配置按鍵切換，在開機是檢測到按鍵按下就從boot_android分區引導boot啟動，即啟動android系統，否則引導linux的boot，啟動linux系統

diff --git a/arch/arm/mach-rockchip/rk3588/rk3588.c b/arch/arm/mach-rockchip/rk3588/rk3588.c

index a8efc4f9b4..e7b94001c1 100644

--- a/arch/arm/mach-rockchip/rk3588/rk3588.c

+++ b/arch/arm/mach-rockchip/rk3588/rk3588.c

@@ -4,6 +4,7 @@

* SPDX-License-Identifier: GPL-2.0+

*/

#include

+#include

#include

#include

#include

@@ -940,3 +941,18 @@ int rk_board_fdt_fixup(const void *blob)

return 0;

}

+

+int board_early_init_r(void)

+{

+

+ printf("board_early_init_r

");

+ if (key_is_pressed(key_read(KEY_BACK))) {

+ env_set("part_suffix", "_android");

+ printf("Part suffix: _android

");

+ } else {

+ env_set("part_suffix", NULL);

+ }

+

+ return 0;

+}

+

diff --git a/configs/rk3588_defconfig b/configs/rk3588_defconfig

index fd6c9114f0..da7ca13626 100644

--- a/configs/rk3588_defconfig

+++ b/configs/rk3588_defconfig

@@ -223,3 +223,4 @@ CONFIG_RK_AVB_LIBAVB_USER=y

CONFIG_OPTEE_CLIENT=y

CONFIG_OPTEE_V2=y

CONFIG_OPTEE_ALWAYS_USE_SECURITY_PARTITION=y

+CONFIG_BOARD_EARLY_INIT_R=y

diff --git a/drivers/input/key-uclass.c b/drivers/input/key-uclass.c

index 1fe9f2c267..0db67fb251 100644

--- a/drivers/input/key-uclass.c

+++ b/drivers/input/key-uclass.c

@@ -39,6 +39,7 @@ uint64_t key_timer(uint64_t base)

static int key_adc_event(struct dm_key_uclass_platdata *uc_key, int adcval)

{

+ KEY_ERR("adcval=%d,max=%d,min=%d

",adcval, uc_key->max, uc_key->min);

return (adcval <= uc_key->max && adcval >= uc_key->min) ?

KEY_PRESS_DOWN : KEY_PRESS_NONE;

}

修改parameter分區表

雙系統的分區表使用同一個，需要把linux和android的分區都加上去，如果兩個系統分區名稱有重復的，需要把android的分區名后面加_android來區分。具體如下：

FIRMWARE_VER: 12.0

MACHINE_MODEL: rk3588_s

MACHINE_ID: 007

MANUFACTURER: rockchip

MAGIC: 0x5041524B

ATAG: 0x00200800

MACHINE: rk3588_s

CHECK_MASK: 0x80

PWR_HLD: 0,0,A,0,1

TYPE: GPT

CMDLINE:mtdparts=rk29xxnand:0x00002000@0x00002000(security),0x00002000@0x00004000(uboot),0x00002000@0x00006000(trust),0x00002000@0x00008000(misc_android),0x00002000@0x0000a000(dtbo),0x00000800@0x0000c000(vbmeta),0x00014000@0x0000c800(boot_android),0x00030000@0x00020800(recovery_android),0x000c0000@0x00050800(backup_android),0x000c0000@0x00110800(cache),0x00008000@0x001d0800(metadata),0x00000800@0x001d8800(baseparameter),0x00614000@0x001d9000(super),0x800000@0x007ed000(userdata_android),0x00002000@0x00fed000(misc),0x00020000@0x00fef000(boot),0x00040000@0x0100f000(recovery),0x00010000@0x0104f000(backup),0x01c00000@0x0105f000(rootfs),0x00040000@0x02c5f000(oem),-@0x02c9f000(userdata:grow)

uuid:rootfs=614e0000-0000-4b53-8000-1d28000054a9

** 其中：

uboot分區是linux和android共用的，其他分區都是獨立的；

Android的misc、boot、 recovery、 backup、 userdata分區因為跟linux重復了所以需要改為misc_android boot_android recovery_android backup_android userdata_android

修改Android系統的fstab

由于Android的分區名改了，所以需要fstab里面對應修改掛在的路徑，如下：

fstab的修改

device/rockchip/common：

diff --git a/scripts/fstab_tools/fstab.in b/scripts/fstab_tools/fstab.in

index 2ec6c265..c5098a0c 100755

--- a/scripts/fstab_tools/fstab.in

+++ b/scripts/fstab_tools/fstab.in

@@ -6,10 +6,10 @@ ${_block_prefix}system/system ext4 ro,barrier=1 ${_flags_vbmeta},first_stage

${_block_prefix}vendor/vendor ext4 ro,barrier=1 ${_flags},first_stage_mount

${_block_prefix}odm /odm ext4 ro,barrier=1 ${_flags},first_stage_mount

-/dev/block/by-name/boot /boot emmc defaults ${_flags_chained}first_stage_mount

+/dev/block/by-name/boot_android /boot emmc defaults ${_flags_chained}first_stage_mount

/dev/block/by-name/cache /cache ext4 noatime,nodiratime,nosuid,nodev,noauto_da_alloc,discard wait,check

/dev/block/by-name/metadata /metadata ext4 nodev,noatime,nosuid,discard,sync wait,formattable,first_stage_mount,check

-/dev/block/by-name/misc /misc emmc defaults defaults

+/dev/block/by-name/misc_android /misc emmc defaults defaults

/devices/platform/*usb* auto vfat defaults voldmanaged=usb:auto

@@ -23,6 +23,6 @@ ${_block_prefix}odm /odm ext4 ro,barrier=1 ${_flags},first_stage_mount

# For sdmmc

/devices/platform/${_sdmmc_device}/mmc_host* autoauto defaults voldmanaged=sdcard1:auto

#Full disk encryption has less effect on rk3326, so default to enable this.

-/dev/block/by-name/userdata /data f2fs noatime,nosuid,nodev,discard,reserve_root=32768,resgid=1065 latemount,wait,check,fileencryption=aes-256-xts:aes-256-cts:v2+inlinecrypt_optimized,keydirectory=/metadata/vold/metadata_encryption,quota,formattable,reservedsize=128M,checkpoint=fs

+/dev/block/by-name/userdata_android /data f2fs noatime,nosuid,nodev,discard,reserve_root=32768,resgid=1065,fsync_mode=nobarrier latemount,wait,check,fileencryption=aes-256-xts:aes-256-cts:v2+inlinecrypt_optimized,keydirectory=/metadata/vold/metadata_encryption,quota,formattable,reservedsize=128M,checkpoint=fs

# for ext4

#/dev/block/by-name/userdata /data ext4 discard,noatime,nosuid,nodev,noauto_da_alloc,data=ordered,user_xattr,barrier=1 latemount,wait,formattable,check,fileencryption=software,quota,reservedsize=128M,checkpoint=block

recovery.fstab的修改

對應的recovery的fstab也要修改，修改產品目錄下的recovery.fstab

device/rockchip/rk3588$

diff --git a/rk3588_s/recovery.fstab b/rk3588_s/recovery.fstab

index f7843a1..6a82ccc 100644

--- a/rk3588_s/recovery.fstab

+++ b/rk3588_s/recovery.fstab

@@ -9,20 +9,20 @@

/dev/block/by-name/system_ext /system_ext ext4 defaults defaults

/dev/block/by-name/vendor_dlkm /vendor_dlkm ext4 defaults defaults

/dev/block/by-name/odm_dlkm /odm_dlkm ext4 defaults defaults

/dev/block/by-name/cache /cache ext4 defaults defaults

/dev/block/by-name/metadata /metadata ext4 defaults defaults

-/dev/block/by-name/userdata /data f2fs defaults defaults

+/dev/block/by-name/userdata_android /data f2fs defaults defaults

/dev/block/by-name/cust /cust ext4 defaults defaults

/dev/block/by-name/custom /custom ext4 defaults defaults

/dev/block/by-name/radical_update /radical_update ext4 defaults defaults

-/dev/block/by-name/misc /misc emmc defaults defaults

+/dev/block/by-name/misc_android /misc emmc defaults defaults

/dev/block/by-name/uboot /uboot emmc defaults defaults

/dev/block/by-name/charge /charge emmc defaults defaults

/dev/block/by-name/resource /resource emmc defaults defaults

/dev/block/by-name/parameter /parameter emmc defaults defaults

-/dev/block/by-name/boot /boot emmc defaults defaults

-/dev/block/by-name/recovery /recovery emmc defaults defaults

-/dev/block/by-name/backup /backup emmc defaults defaults

+/dev/block/by-name/boot_android /boot emmc defaults defaults

+/dev/block/by-name/recovery_android /recovery emmc defaults defaults

+/dev/block/by-name/backup_android /backup emmc defaults defaults

/dev/block/by-name/frp /frp emmc defaults defaults

/dev/block/by-name/trust /trust emmc defaults defaults

/dev/block/by-name/baseparamer /baseparamer emmc defaults defaults

Linux系統固件

linux系統的固件軟件不需要修改，可以直接用編譯好的固件

固件燒寫

固件需要燒寫linux和android的固件，如下圖，可以直接右鍵導入上面修改好的parameter.txt文件，然后刪除不需要的燒寫固件分區即可。

注意：uboot、loader、parameter這三個是共用的，只需要燒一份即可。

驗證

固件燒寫完成后第一次默認開機會從linux系統啟動，linux正常啟動后可以按住ESC按鍵，然后重啟系統，ESC要一直按住到android系統啟動完成。

原作者：loitawu