MPC8309 kernel boot from NOR (XIP)

ajaybhargav · ‎12-19-2014

I have MPC8309 Kit with me. I want to tell u-boot to boot kernel directly from NOR rather than u-boot copy kernel to RAM and then boot. Is it possible in PowerPC? If yes please provide any helpful information.

yipingwang · ‎12-22-2014

Hello Ajay Bhargav,

It is possible, please try the following method.

On MPC8309SOM, the NOR Flash is allocated as the following.

Range Start Range End Definition

0xfe00_0000 0xfe05_ffff U-Boot

0xfe0a_0000 0xfe2f_ffff Kernel

0xfe30_0000 0xfe7e_ffff Ramdisk file system

0xfe7f_0000 0xfe7f_3fff DTB

Under u-boot after deploying uImage, rootfs.ext2.gz.uboot and dtb file at the specific addresses, and configure u-boot environment as the following.

setenv ramargs 'setenv bootargs root=/dev/ram rw console=ttyS0,115200'

setenv bootcmd 'run ramargs; bootm 0xfe0a0000 0xfe300000 0xfe7f0000'

Have a great day,
Yiping

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ajaybhargav · ‎12-22-2014

Hi Yiping,

even if I run uImage from NOR (which I am doing already), U-Boot relocates kernel to RAM before running it from Flash.

Display message "Loading Kernel Image... OK"

and after that dtb gets relocated to ram at a different address and then booting starts.

So "Loading Kernel Image... OK" itself takes around ~1sec. which I want to eliminate here. Any suggestions?

Regards,

Ajay Bhargav

scottwood · ‎12-22-2014

This is not normally supported by U-Boot with bootm, though you might be able to do it without U-Boot changes by using the bootm subcommands and skipping loados, with the uImage specifying the flash address as the entry point.

However, that isn't going to make Linux run out of flash -- it just means that early Linux code will do the copy instead.

yipingwang · ‎12-22-2014

Hello Ajay Bhargav,

Would you please attach the whole Kernel boot log?

Thanks,

Yiping

ajaybhargav · ‎12-22-2014

Here is the u-boot + kernel log.

My kernel and u-boot is ported from stock MPC8309 kernel v2.6.34 that comes with Ltib. I am testing it on MPC8309 KIT.

U-Boot 2014.04-g678d3b1 (Dec 17 2014 - 17:12:45)MPC83XX

Reset Status:

CPU: e300c3, MPC8309E, Rev: 1.1 at 333.333 MHz, CSB: 133.333 MHz

Board: MPC8309 Test Board

Watchdog enabled

I2C: ready

DRAM: 256 MiB (DDR2, 32-bit, ECC off, 266.667 MHz)

Flash: 32 MiB

Firmware 'Microcode version 0.0.0 for MPC8306 r1.0' for 8306 V1.0

QE: uploading microcode 'Microcode for MPC8306 r1.0'

NAND: 512 MiB

MMC: FSL_SDHC: 0

In: serial

Out: serial

Err: serial

Net: UEC0, UEC1

Hit any key to stop autoboot: 0

MPC8309> mtdparts

device nor0 <nor>, # parts = 7

#: name size offset mask_flags

0: UBoot 0x00100000 0x00000000 0

1: env 0x00020000 0x00100000 0

2: ucode 0x00020000 0x00120000 0

3: dtb 0x00020000 0x00140000 0

4: reserved 0x000a0000 0x00160000 0

5: kernel 0x00800000 0x00200000 0

6: fs 0x01600000 0x00a00000 0

device nand0 <nand>, # parts = 4

#: name size offset mask_flags

0: UBoot-nand 0x00180000 0x00000000 0

1: DTB-nand 0x00080000 0x00180000 0

2: Kernel-nand 0x00800000 0x00200000 0

3: fs-nand 0x1f600000 0x00a00000 0

active partition: nor0,0 - (UBoot) 0x00100000 @ 0x00000000

defaults:

mtdids : nor0=nor,nand0=nand

mtdparts: mtdparts=nor:1M(UBoot),128K(env),128K(ucode),128K(dtb),640K(reserved),8M(kernel),-(fs);nand:1536K(UBoot-nand),512K(DTB-nand),8M(Kernel-nand))

MPC8309> boot

## Booting kernel from Legacy Image at fe200000 ...

Image Name: MPC8309 Linux 2.6.39

Image Type: PowerPC Linux Kernel Image (uncompressed)

Data Size: 4133632 Bytes = 3.9 MiB

Load Address: 00000000

Entry Point: 00000000

## Flattened Device Tree blob at fe140000

Booting using the fdt blob at 0xfe140000

Loading Kernel Image ... OK

Loading Device Tree to 007fa000, end 007ff46b ... OK

setup_arch: bootmem

mpc8309_setup_arch()

arch: exit

rtc-m41t80 0-0068: hctosys: unable to read the hardware clock

Creating mount points

Starting logging: OK

Initializing random number generator... done.

Starting network...

sd 0:0:0:0: [sda] Assuming drive cache: write through

udhcpc (v1.22.1) started

Sending discover...

No lease, failing

udhcpc (v1.22.1) started

Sending discover...

No lease, failing

Starting dropbear sshd: OK

Mounting USB Storage Device: OK

Welcome to Buildroot

mpc8309 login:

My Bootargs and bootcommand is:

bootargs=console=ttyS0,115200n8 root=ubi0:rootfs rw ubi.mtd=10,2048 noinitrd rootfstype=ubifs rootwait quiet

bootcmd=bootm 0xfe200000 - 0xfe140000

As you can see both kernel and dtb gets relocated before booting:

Loading Kernel Image ... OK

Loading Device Tree to 007fa000, end 007ff46b ... OK

Thanks in advance.