[U-Boot] [EXT] Re: [ARMv8] kernel entry point
Pankaj Bansal
pankaj.bansal at nxp.com
Fri May 10 14:40:52 UTC 2019
Hi Tom,
Further update.
I asked this question to linux maintainer, and he pointed out that load address that I am using is not correct.
The linux load address should be (2 MB aligned + text_offset).
The text_offset can be obtained from first 64 bytes in linux Image.
For our use case it comes out to be 0x81080000.
One thing that I wonder though is, that I did not receive any warning or error from uboot about load address.
Can such warning/error be added in uboot ?
Regards,
Pankaj Bansal
> -----Original Message-----
> From: Pankaj Bansal
> Sent: Tuesday, 7 May, 2019 03:48 PM
> To: 'Tom Rini' <trini at konsulko.com>
> Cc: 'u-boot at lists.denx.de' <u-boot at lists.denx.de>; Prabhakar Kushwaha
> <prabhakar.kushwaha at nxp.com>; Varun Sethi <V.Sethi at nxp.com>
> Subject: RE: [EXT] Re: [ARMv8] kernel entry point
>
> On further testing I tried to boot the linux from ATF (https://github.com/ARM-
> software/arm-trusted-firmware)
> Without using u-boot
> Even with ATF, the linux is not able to boot from 0x81000000, but is able to boot
> from 0x80080000 Seems like linux issue and not u-boot issue.
> I will ask this question in linux community.
>
> Regards,
> Pankaj Bansal
>
> > -----Original Message-----
> > From: Pankaj Bansal
> > Sent: Tuesday, 7 May, 2019 08:30 AM
> > To: 'Tom Rini' <trini at konsulko.com>
> > Cc: 'u-boot at lists.denx.de' <u-boot at lists.denx.de>; Prabhakar Kushwaha
> > <prabhakar.kushwaha at nxp.com>; Varun Sethi <V.Sethi at nxp.com>
> > Subject: RE: [EXT] Re: [ARMv8] kernel entry point
> >
> > Hi Tom,
> >
> > In order to determine whether linux entry point has been called or
> > not, I put a loop in kernel:
> >
> > diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index
> > 261f3f88364c..dea6cb8baa6a 100644
> > --- a/arch/arm64/kernel/head.S
> > +++ b/arch/arm64/kernel/head.S
> > @@ -80,6 +80,7 @@ _head:
> > * its opcode forms the magic "MZ" signature required by UEFI.
> > */
> > add x13, x18, #0x16
> > + b .
> > b stext
> > #else
> > b stext // branch to kernel start, magic
> >
> > This loop is being executed when I boot the kernel, but after I jump
> > over this loop there is no log.
> > Does it mean that bootloader is working fine, it's the linux that is
> > not able to boot from 0x81000000 (0x80000000 being the RAM starting
> address) ?
> >
> > Regards,
> > Pankaj Bansal
> >
> > > -----Original Message-----
> > > From: Pankaj Bansal
> > > Sent: Monday, 6 May, 2019 07:04 PM
> > > To: Tom Rini <trini at konsulko.com>
> > > Cc: u-boot at lists.denx.de; Prabhakar Kushwaha
> > > <prabhakar.kushwaha at nxp.com>; Varun Sethi <V.Sethi at nxp.com>
> > > Subject: RE: [EXT] Re: [ARMv8] kernel entry point
> > >
> > >
> > >
> > > > -----Original Message-----
> > > > From: Tom Rini <trini at konsulko.com>
> > > > Sent: Monday, 6 May, 2019 06:59 PM
> > > > To: Pankaj Bansal <pankaj.bansal at nxp.com>
> > > > Cc: u-boot at lists.denx.de; Prabhakar Kushwaha
> > > > <prabhakar.kushwaha at nxp.com>; Varun Sethi <V.Sethi at nxp.com>
> > > > Subject: [EXT] Re: [ARMv8] kernel entry point
> > > >
> > > > On Mon, May 06, 2019 at 01:06:45PM +0000, Pankaj Bansal wrote:
> > > >
> > > > > Hi Tom et. Al,
> > > > >
> > > > > I am facing an issue while booting linux on our ARMv8 based platform.
> > > > > In our platform DDR address starts from 0x80000000.
> > > > > If I make the linux kernel entry point 0x80080000 in mkimage,
> > > > > then linux boots
> > > > fine.
> > > > > BUT, if I make the linux image entry point as 0x81000000 in
> > > > > mkimage, the
> > > > kernel doesn't boot.
> > > > >
> > > > > => bootm 0xa0000000 - 0xa1000000 ## Current stack ends at
> > > > > 0xfbb24400 ## Booting kernel from Legacy Image at
> > > > a0000000 ...
> > > > > Image Name: linux
> > > > > Image Type: AArch64 Linux Kernel Image (gzip compressed)
> > > > > Data Size: 9110442 Bytes = 8.7 MiB
> > > > > Load Address: 81000000
> > > > > Entry Point: 81000000
> > > > > Verifying Checksum ... OK
> > > > > ## Flattened Device Tree blob at a1000000
> > > > > Booting using the fdt blob at 0xa1000000
> > > > > Uncompressing Kernel Image ... OK
> > > > > using: FDT
> > > > > reserving fdt memory region: addr=80000000 size=10000
> > > > > Loading Device Tree to 000000009fff6000, end 000000009ffff2f8 ...
> > > > > OK ## Transferring control to Linux (at address 81000000)...
> > > > >
> > > > > Starting kernel ...
> > > > >
> > > > > I get no kernel logs after this. I am failing to understand why.
> > > > > Can you please help me in debugging this issue?
> > > >
> > > > Why are you using a legacy image on AArch64 at all? You should be
> > > > using either the kernel Image (and booti) or a FIT image.
> > >
> > > This issue is coming even if I use FIT image.
> > >
> > > => bootm 0xa0000000#lx2160ardb
> > > ## Current stack ends at 0xfbb24400 ## Loading kernel from FIT Image
> > > at
> > > a0000000 ...
> > > Using 'lx2160ardb' configuration
> > > Trying 'kernel' kernel subimage
> > > Description: ARM64 Kernel
> > > Type: Kernel Image
> > > Compression: gzip compressed
> > > Data Start: 0xa00000d0
> > > Data Size: 9110442 Bytes = 8.7 MiB
> > > Architecture: AArch64
> > > OS: Linux
> > > Load Address: 0x81000000
> > > Entry Point: 0x81000000
> > > Hash algo: crc32
> > > Hash value: 39f59891
> > > Verifying Hash Integrity ... crc32+ OK ## Loading ramdisk from
> > > FIT Image at
> > > a0000000 ...
> > > Using 'lx2160ardb' configuration
> > > Trying 'initrd' ramdisk subimage
> > > Description: initrd for arm64
> > > Type: RAMDisk Image
> > > Compression: uncompressed
> > > Data Start: 0xa08b055c
> > > Data Size: 29171975 Bytes = 27.8 MiB
> > > Architecture: AArch64
> > > OS: Linux
> > > Load Address: 0x00000000
> > > Entry Point: 0x00000000
> > > Hash algo: crc32
> > > Hash value: 23038325
> > > Verifying Hash Integrity ... crc32+ OK ## Loading fdt from FIT
> > > Image at
> > > a0000000 ...
> > > Using 'lx2160ardb' configuration
> > > Trying 'lx2160ardb-dtb' fdt subimage
> > > Description: lx2160ardb-dtb
> > > Type: Flat Device Tree
> > > Compression: uncompressed
> > > Data Start: 0xa249071c
> > > Data Size: 25337 Bytes = 24.7 KiB
> > > Architecture: AArch64
> > > Load Address: 0x90000000
> > > Hash algo: crc32
> > > Hash value: 8e4d595f
> > > Verifying Hash Integrity ... crc32+ OK
> > > Loading fdt from 0xa249071c to 0x90000000
> > > Booting using the fdt blob at 0x90000000
> > > Uncompressing Kernel Image ... OK
> > > using: FDT
> > > reserving fdt memory region: addr=80000000 size=10000
> > > Loading Device Tree to 000000009fff6000, end 000000009ffff2f8 ...
> > > OK ## Transferring control to Linux (at address 81000000)...
> > >
> > > Starting kernel ...
> > >
> > >
> > > >
> > > > --
> > > > Tom
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Subject: RE: [ARMv8] kernel entry point
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