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

[王翔]

This elf file is position-independent and can be loaded to any location. We can add a simple script to handle it.

1. Convert vmlinux to binary by objcopy, the binary file name is flat_file

2. Write a simple assembly file (tmp.S), convert binary to object, the file name is obj_file
```
.section .text
.globl _start
_start:
.incbin "flat_file"
```
command: as tmp.S -o obj_file

3. Relink. Linker script like this(tmp.ld):
```
ENTRY(_start)

SECTIONS {
  . = target_address;
  .text : { *(.text) }
}
```
command: ld -T tmp.ld obj_file

在2018年09月25 20时51分, "Philipp Hug"写道:

Am Di., 25. Sep. 2018 um 13:50 Uhr schrieb Jonathan Neuschäfer :

Would FIT support require discussion/cooperation with other projects
like Linux or u-boot?

What seems to be missing is the kernel image format to be used within the FIT. e.g. look at arm64:
https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/head.S#L73
https://github.com/coreboot/coreboot/blob/master/src/arch/arm64/fit_payload....

Philipp

Loading Linux payloads on RISC-V

[ron minnich]

But the kernel can start anywhere. I don't see a reason to do this complex
objcopy step when all that is needed is to have cbfstool set some entries
in the SELF or just have selfboot use "0" to mean "somewhere useful"? Did I
miss something?

On Tue, Sep 25, 2018 at 10:32 PM 王翔  wrote:
> This elf file is position-independent and can be loaded to any location.
> We can add a simple script to handle it.
>
> Convert vmlinux to binary by objcopy, the binary file name is flat_file
>
> Write a simple assembly file (tmp.S), convert binary to object, the
>
> file name is obj_file
> .section .text
> .globl _start
> _start:
> .incbin "flat_file"
>
> command: as tmp.S -o obj_file
> Relink. Linker script like this(tmp.ld):
> ENTRY(_start)
>
> SECTIONS {
>   . = target_address;
>   .text : { *(.text) }
> }
>
> command: ld -T tmp.ld obj_file
>
> 在2018年09月25 20时51分, "Philipp Hug"写道:
>
> Am Di., 25. Sep. 2018 um 13:50 Uhr schrieb Jonathan Neuschäfer <
> [e-mail]>:
> > Would FIT support require discussion/cooperation with other projects
> > like Linux or u-boot?
> >
> > What seems to be missing is the kernel image format to be used within the
>
> FIT. e.g. look at arm64:
> https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/head.S#L73
>
> https://github.com/coreboot/coreboot/blob/master/src/arch/arm64/fit_payload....
>
> Philipp