[coreboot] Loading Linux payloads on RISC-V

[Patrick Rudolph]

Can you make use of the uImage/FIT [1] mechanism coreboot supports ?
It just needs some architecture specific code.

Can you provide a ling to the Linux calling conventions for riscv ?

[1] https://doc.coreboot.org/lib/payloads/fit.html

Regards,
Patrick
On 2018-09-23 04:59 PM, ron minnich wrote:
> ah sorry I forgot.
> 
> I think selfboot could be reworked (and should be) to interpret "0" as
> "somewhere useful"?
> 
> On Sat, Sep 22, 2018 at 10:47 PM ron minnich <rminnich at gmail.com>
> wrote:
> 
>> shouldn't we fix the riscv kernel build process? it's producing bad
>> elf files?
>>
>> On Sat, Sep 22, 2018 at 4:40 PM Jonathan Neuschäfer
>> <j.neuschaefer at gmx.net> wrote:
>>
>>> Hi,
>>>
>>> we've discussed this briefly at OSFC: Linux's ELF file (vmlinux)
>>> currently has segments starting at 0x0 (if you look at the
>>> physical
>>> address field) and an entry point at 0xffffffe000000000:
>>>
>>>> $ readelf -l vmlinux
>>>>
>>>> Elf file type is EXEC (Executable file)
>>>> Entry point 0xffffffe000000000
>>>> There are 3 program headers, starting at offset 64
>>>>
>>>> Program Headers:
>>>> Type           Offset             VirtAddr           PhysAddr
>>>> FileSiz            MemSiz              Flags
>>> Align
>>>> LOAD           0x0000000000001000 0xffffffe000000000
>>> 0x0000000000000000
>>>> 0x000000000000ffce 0x000000000000ffce  R E
>>> 0x1000
>>>> LOAD           0x0000000000011000 0xffffffe000010000
>>> 0x0000000000010000
>>>> 0x00000000002cda3c 0x00000000002cda3c  RWE
>>> 0x1000
>>>> NOTE           0x00000000002dea00 0xffffffe0002dda00
>>> 0x00000000002dda00
>>>> 0x000000000000003c 0x000000000000003c  R
>>> 0x4
>>>>
>>>> Section to Segment mapping:
>>>> Segment Sections...
>>>> 00     .init.text
>>>> 01     .init.data .exit.text .data..percpu .text
>>> .softirqentry.text .rodata __param __modver .srodata .data
>>> __bug_table .sdata .bss __ex_table .notes
>>>> 02     .notes
>>>
>>> coreboot's SELF loader rightly points out that 0x0 is not in RAM:
>>>
>>>> Loading segment from ROM address 0x00000000200287b8
>>>> code (compression=0)
>>>> New segment dstaddr 0x0 memsize 0xffce srcaddr 0x2002880c
>>> filesize 0xffce
>>>> Loading segment from ROM address 0x00000000200287d4
>>>> code (compression=0)
>>>> New segment dstaddr 0x10000 memsize 0x2cda3c srcaddr
>>> 0x200387da filesize 0x2cda3c
>>>> Loading segment from ROM address 0x00000000200287f0
>>>> Entry Point 0xffffffe000000000
>>>> SELF Payload doesn't target RAM:
>>>> Failed Segment: 0x0, 65486 bytes
>>>> 0. 0000000080000000-0000000080011fff: RAMSTAGE
>>>> 1. 0000000080012000-000000008003ffff: RAM
>>>> 2. 0000000080040000-0000000080044fff: RAMSTAGE
>>>> 3. 0000000080045000-00000000fffdbfff: RAM
>>>> 4. 00000000fffdc000-00000000ffffffff: CONFIGURATION TABLES
>>>> 5. 0000000100000000-000000027fffffff: RAM
>>>> Payload not loaded.
>>>
>>> How should we solve this?
>>>
>>> One option I see is to keep CONFIG_PAYLOAD_ELF as is, and add
>>> quirks to
>>> CONFIG_PAYLOAD_LINUX.
>>>
>>> Jonathan