Re: [coreboot] Loading Linux payloads on RISC-V

[Aaron Durbin]

On Sun, Sep 23, 2018 at 9:00 AM ron minnich  wrote:
> ah sorry I forgot.
>
> I think selfboot could be reworked (and should be) to interpret "0" as "somewhere useful"?

Why is the kernel being loaded at 0?
> On Sat, Sep 22, 2018 at 10:47 PM ron minnich  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  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
> > > > 0000000080012000-000000008003ffff: RAM
> > > > 0000000080040000-0000000080044fff: RAMSTAGE
> > > > 0000000080045000-00000000fffdbfff: RAM
> > > > 00000000fffdc000-00000000ffffffff: CONFIGURATION TABLES
> > > > 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