Re: [v4 PATCH] RISC-V: Add an Image header that boot loader can parse.
> On 5/28/19 3:47 AM, Ard Biesheuvel wrote: >> On Tue, 28 May 2019 at 12:34, Anup Patel wrote: >> >> >> >>> -Original Message- >>> From: Karsten Merker >>> Sent: Tuesday, May 28, 2019 1:53 PM >>> To: Anup Patel >>> Cc: Troy Benjegerdes ; Karsten Merker >>> ; Albert Ou ; Jonathan >>> Corbet ; Ard Biesheuvel ; >>> linux-kernel@vger.kernel.org List ; Zong Li >>> ; Atish Patra ; Palmer >>> Dabbelt ; paul.walms...@sifive.com; Nick Kossifidis >>> ; linux-ri...@lists.infradead.org; >>> marek.va...@gmail.com >>> Subject: Re: [v4 PATCH] RISC-V: Add an Image header that boot loader can >>> parse. >>> >>>> On Tue, May 28, 2019 at 03:54:02AM +, Anup Patel wrote: >>>>>> From: Troy Benjegerdes >>>>>>> On May 27, 2019, at 5:16 PM, Karsten Merker >>>>>> wrote: >>>>>> >>>>>>> On Mon, May 27, 2019 at 04:34:57PM +0200, Ard Biesheuvel wrote: >>>>>>> On Fri, 24 May 2019 at 06:18, Atish Patra >>> wrote: >>>>>>>> Currently, the last stage boot loaders such as U-Boot can accept >>>>>>>> only uImage which is an unnecessary additional step in >>>>>>>> automating boot process. >>>>>>>> >>>>>>>> Add an image header that boot loader understands and boot Linux >>>>>>>> from flat Image directly. >>>>>>>> >>>>>>>> This header is based on ARM64 boot image header and provides an >>>>>>>> opportunity to combine both ARM64 & RISC-V image headers in >>> future. >>>>>>>> >>>>>>>> Also make sure that PE/COFF header can co-exist in the same >>>>>>>> image so that EFI stub can be supported for RISC-V in future. >>>>>>>> EFI specification needs PE/COFF image header in the beginning of >>>>>>>> the kernel image in order to load it as an EFI application. In >>>>>>>> order to support EFI stub, code0 should be replaced with "MZ" >>>>>>>> magic string and res4(at offset 0x3c) should point to the rest >>>>>>>> of the PE/COFF header (which will be added during EFI support). >>>>>> [...] >>>>>>>> Documentation/riscv/boot-image-header.txt | 50 >>>>> ++ >>>>>>>> arch/riscv/include/asm/image.h| 64 >>> +++ >>>>>>>> arch/riscv/kernel/head.S | 32 >>>>>>>> 3 files changed, 146 insertions(+) create mode 100644 >>>>>>>> Documentation/riscv/boot-image-header.txt >>>>>>>> create mode 100644 arch/riscv/include/asm/image.h >>>>>>>> >>>>>>>> diff --git a/Documentation/riscv/boot-image-header.txt >>>>>>>> b/Documentation/riscv/boot-image-header.txt >>>>>>>> new file mode 100644 >>>>>>>> index ..68abc2353cec >>>>>>>> --- /dev/null >>>>>>>> +++ b/Documentation/riscv/boot-image-header.txt >>>>>>>> @@ -0,0 +1,50 @@ >>>>>>>> + Boot image header in RISC-V >>>>>>>> + Linux >>>>>>>> + >>>>>>>> + = >>>>>>>> + >>>>>>>> +Author: Atish Patra Date : 20 May 2019 >>>>>>>> + >>>>>>>> +This document only describes the boot image header details for >>>>>>>> +RISC-V >>>>> Linux. >>>>>>>> +The complete booting guide will be available at >>>>> Documentation/riscv/booting.txt. >>>>>>>> + >>>>>>>> +The following 64-byte header is present in decompressed Linux >>>>>>>> +kernel >>>>> image. >>>>>>>> + >>>>>>>> + u32 code0;/* Executable code */ >>>>>>>> + u32 code1;/* Executable code */ >>>>>>> >>>>>>> Apologies for not mentioning this in my previous reply, but given >>>>>>> that you alrea
Re: [v4 PATCH] RISC-V: Add an Image header that boot loader can parse.
On Tue, 28 May 2019 at 12:34, Anup Patel wrote: > > > > > -Original Message- > > From: Karsten Merker > > Sent: Tuesday, May 28, 2019 1:53 PM > > To: Anup Patel > > Cc: Troy Benjegerdes ; Karsten Merker > > ; Albert Ou ; Jonathan > > Corbet ; Ard Biesheuvel ; > > linux-kernel@vger.kernel.org List ; Zong Li > > ; Atish Patra ; Palmer > > Dabbelt ; paul.walms...@sifive.com; Nick Kossifidis > > ; linux-ri...@lists.infradead.org; > > marek.va...@gmail.com > > Subject: Re: [v4 PATCH] RISC-V: Add an Image header that boot loader can > > parse. > > > > On Tue, May 28, 2019 at 03:54:02AM +, Anup Patel wrote: > > > > From: Troy Benjegerdes > > > > > On May 27, 2019, at 5:16 PM, Karsten Merker > > > > wrote: > > > > > > > > > > On Mon, May 27, 2019 at 04:34:57PM +0200, Ard Biesheuvel wrote: > > > > >> On Fri, 24 May 2019 at 06:18, Atish Patra > > wrote: > > > > >>> Currently, the last stage boot loaders such as U-Boot can accept > > > > >>> only uImage which is an unnecessary additional step in > > > > >>> automating boot process. > > > > >>> > > > > >>> Add an image header that boot loader understands and boot Linux > > > > >>> from flat Image directly. > > > > >>> > > > > >>> This header is based on ARM64 boot image header and provides an > > > > >>> opportunity to combine both ARM64 & RISC-V image headers in > > future. > > > > >>> > > > > >>> Also make sure that PE/COFF header can co-exist in the same > > > > >>> image so that EFI stub can be supported for RISC-V in future. > > > > >>> EFI specification needs PE/COFF image header in the beginning of > > > > >>> the kernel image in order to load it as an EFI application. In > > > > >>> order to support EFI stub, code0 should be replaced with "MZ" > > > > >>> magic string and res4(at offset 0x3c) should point to the rest > > > > >>> of the PE/COFF header (which will be added during EFI support). > > > > > [...] > > > > >>> Documentation/riscv/boot-image-header.txt | 50 > > > > ++ > > > > >>> arch/riscv/include/asm/image.h| 64 > > +++ > > > > >>> arch/riscv/kernel/head.S | 32 > > > > >>> 3 files changed, 146 insertions(+) create mode 100644 > > > > >>> Documentation/riscv/boot-image-header.txt > > > > >>> create mode 100644 arch/riscv/include/asm/image.h > > > > >>> > > > > >>> diff --git a/Documentation/riscv/boot-image-header.txt > > > > >>> b/Documentation/riscv/boot-image-header.txt > > > > >>> new file mode 100644 > > > > >>> index ..68abc2353cec > > > > >>> --- /dev/null > > > > >>> +++ b/Documentation/riscv/boot-image-header.txt > > > > >>> @@ -0,0 +1,50 @@ > > > > >>> + Boot image header in RISC-V > > > > >>> + Linux > > > > >>> + > > > > >>> + = > > > > >>> + > > > > >>> +Author: Atish Patra Date : 20 May 2019 > > > > >>> + > > > > >>> +This document only describes the boot image header details for > > > > >>> +RISC-V > > > > Linux. > > > > >>> +The complete booting guide will be available at > > > > Documentation/riscv/booting.txt. > > > > >>> + > > > > >>> +The following 64-byte header is present in decompressed Linux > > > > >>> +kernel > > > > image. > > > > >>> + > > > > >>> + u32 code0;/* Executable code */ > > > > >>> + u32 code1;/* Executable code */ > > > > >> > > > > >> Apologies for not mentioning this in my previous reply, but given > > > > >> that you already know that you will need to put the magic string > > > > >> MZ at offset 0x0, it makes more sense to not put any code there > > > >
RE: [v4 PATCH] RISC-V: Add an Image header that boot loader can parse.
> -Original Message- > From: Karsten Merker > Sent: Tuesday, May 28, 2019 1:53 PM > To: Anup Patel > Cc: Troy Benjegerdes ; Karsten Merker > ; Albert Ou ; Jonathan > Corbet ; Ard Biesheuvel ; > linux-kernel@vger.kernel.org List ; Zong Li > ; Atish Patra ; Palmer > Dabbelt ; paul.walms...@sifive.com; Nick Kossifidis > ; linux-ri...@lists.infradead.org; > marek.va...@gmail.com > Subject: Re: [v4 PATCH] RISC-V: Add an Image header that boot loader can > parse. > > On Tue, May 28, 2019 at 03:54:02AM +, Anup Patel wrote: > > > From: Troy Benjegerdes > > > > On May 27, 2019, at 5:16 PM, Karsten Merker > > > wrote: > > > > > > > > On Mon, May 27, 2019 at 04:34:57PM +0200, Ard Biesheuvel wrote: > > > >> On Fri, 24 May 2019 at 06:18, Atish Patra > wrote: > > > >>> Currently, the last stage boot loaders such as U-Boot can accept > > > >>> only uImage which is an unnecessary additional step in > > > >>> automating boot process. > > > >>> > > > >>> Add an image header that boot loader understands and boot Linux > > > >>> from flat Image directly. > > > >>> > > > >>> This header is based on ARM64 boot image header and provides an > > > >>> opportunity to combine both ARM64 & RISC-V image headers in > future. > > > >>> > > > >>> Also make sure that PE/COFF header can co-exist in the same > > > >>> image so that EFI stub can be supported for RISC-V in future. > > > >>> EFI specification needs PE/COFF image header in the beginning of > > > >>> the kernel image in order to load it as an EFI application. In > > > >>> order to support EFI stub, code0 should be replaced with "MZ" > > > >>> magic string and res4(at offset 0x3c) should point to the rest > > > >>> of the PE/COFF header (which will be added during EFI support). > > > > [...] > > > >>> Documentation/riscv/boot-image-header.txt | 50 > > > ++ > > > >>> arch/riscv/include/asm/image.h| 64 > +++ > > > >>> arch/riscv/kernel/head.S | 32 > > > >>> 3 files changed, 146 insertions(+) create mode 100644 > > > >>> Documentation/riscv/boot-image-header.txt > > > >>> create mode 100644 arch/riscv/include/asm/image.h > > > >>> > > > >>> diff --git a/Documentation/riscv/boot-image-header.txt > > > >>> b/Documentation/riscv/boot-image-header.txt > > > >>> new file mode 100644 > > > >>> index ..68abc2353cec > > > >>> --- /dev/null > > > >>> +++ b/Documentation/riscv/boot-image-header.txt > > > >>> @@ -0,0 +1,50 @@ > > > >>> + Boot image header in RISC-V > > > >>> + Linux > > > >>> + > > > >>> + = > > > >>> + > > > >>> +Author: Atish Patra Date : 20 May 2019 > > > >>> + > > > >>> +This document only describes the boot image header details for > > > >>> +RISC-V > > > Linux. > > > >>> +The complete booting guide will be available at > > > Documentation/riscv/booting.txt. > > > >>> + > > > >>> +The following 64-byte header is present in decompressed Linux > > > >>> +kernel > > > image. > > > >>> + > > > >>> + u32 code0;/* Executable code */ > > > >>> + u32 code1;/* Executable code */ > > > >> > > > >> Apologies for not mentioning this in my previous reply, but given > > > >> that you already know that you will need to put the magic string > > > >> MZ at offset 0x0, it makes more sense to not put any code there > > > >> at all, but educate the bootloader that the first executable > > > >> instruction is at offset 0x20, and put the spare fields right > > > >> after it in case you ever need more than 2 slots. (On arm64, we > > > >> were lucky to be able to find an opcode that happened to contain > > > >> the MZ bit pattern and act almost like a NOP, but it seems silly > > > >> to rely on that for R
RE: [v4 PATCH] RISC-V: Add an Image header that boot loader can parse.
> -Original Message- > From: Troy Benjegerdes > Sent: Tuesday, May 28, 2019 5:11 AM > To: Karsten Merker > Cc: Ard Biesheuvel ; Albert Ou > ; Jonathan Corbet ; Anup Patel > ; Zong Li ; Atish Patra > ; Nick Kossifidis ; Palmer Dabbelt > ; paul.walms...@sifive.com; linux- > ri...@lists.infradead.org; marek.va...@gmail.com > Subject: Re: [v4 PATCH] RISC-V: Add an Image header that boot loader can > parse. > > > > > On May 27, 2019, at 5:16 PM, Karsten Merker > wrote: > > > > On Mon, May 27, 2019 at 04:34:57PM +0200, Ard Biesheuvel wrote: > >> On Fri, 24 May 2019 at 06:18, Atish Patra wrote: > >>> Currently, the last stage boot loaders such as U-Boot can accept > >>> only uImage which is an unnecessary additional step in automating > >>> boot process. > >>> > >>> Add an image header that boot loader understands and boot Linux from > >>> flat Image directly. > >>> > >>> This header is based on ARM64 boot image header and provides an > >>> opportunity to combine both ARM64 & RISC-V image headers in future. > >>> > >>> Also make sure that PE/COFF header can co-exist in the same image so > >>> that EFI stub can be supported for RISC-V in future. EFI > >>> specification needs PE/COFF image header in the beginning of the > >>> kernel image in order to load it as an EFI application. In order to > >>> support EFI stub, code0 should be replaced with "MZ" magic string > >>> and res4(at offset 0x3c) should point to the rest of the PE/COFF > >>> header (which will be added during EFI support). > > [...] > >>> Documentation/riscv/boot-image-header.txt | 50 > ++ > >>> arch/riscv/include/asm/image.h| 64 +++ > >>> arch/riscv/kernel/head.S | 32 > >>> 3 files changed, 146 insertions(+) > >>> create mode 100644 Documentation/riscv/boot-image-header.txt > >>> create mode 100644 arch/riscv/include/asm/image.h > >>> > >>> diff --git a/Documentation/riscv/boot-image-header.txt > >>> b/Documentation/riscv/boot-image-header.txt > >>> new file mode 100644 > >>> index ..68abc2353cec > >>> --- /dev/null > >>> +++ b/Documentation/riscv/boot-image-header.txt > >>> @@ -0,0 +1,50 @@ > >>> + Boot image header in RISC-V Linux > >>> + > >>> + = > >>> + > >>> +Author: Atish Patra Date : 20 May 2019 > >>> + > >>> +This document only describes the boot image header details for RISC-V > Linux. > >>> +The complete booting guide will be available at > Documentation/riscv/booting.txt. > >>> + > >>> +The following 64-byte header is present in decompressed Linux kernel > image. > >>> + > >>> + u32 code0;/* Executable code */ > >>> + u32 code1;/* Executable code */ > >> > >> Apologies for not mentioning this in my previous reply, but given > >> that you already know that you will need to put the magic string MZ > >> at offset 0x0, it makes more sense to not put any code there at all, > >> but educate the bootloader that the first executable instruction is > >> at offset 0x20, and put the spare fields right after it in case you > >> ever need more than 2 slots. (On arm64, we were lucky to be able to > >> find an opcode that happened to contain the MZ bit pattern and act > >> almost like a NOP, but it seems silly to rely on that for RISC-V as > >> well) > >> > >> So something like > >> > >> u16 pe_res1; /* MZ for EFI bootable images, don't care otherwise */ > >> u8 magic[6];/* "RISCV\0" > >> > >> u64 text_offset; /* Image load offset, little endian */ > >> u64 image_size; /* Effective Image size, little endian */ > >> u64 flags;/* kernel flags, little endian */ > >> > >> u32 code0;/* Executable code */ > >> u32 code1;/* Executable code */ > >> > >> u64 reserved[2]; /* reserved for future use */ > >> > >> u32 version; /* Version of this header */ > >> u32 pe_res2; /* Reserved for PE COFF offset */ > > > > Hello, > > > > wouldn&#x
Re: [v4 PATCH] RISC-V: Add an Image header that boot loader can parse.
On Thu 23 May 2019 at 21:18, Atish Patra wrote: > Currently, the last stage boot loaders such as U-Boot can accept only > uImage which is an unnecessary additional step in automating boot > process. > > Add an image header that boot loader understands and boot Linux from > flat Image directly. > > This header is based on ARM64 boot image header and provides an > opportunity to combine both ARM64 & RISC-V image headers in future. > > Also make sure that PE/COFF header can co-exist in the same image so > that EFI stub can be supported for RISC-V in future. EFI specification > needs PE/COFF image header in the beginning of the kernel image in order > to load it as an EFI application. In order to support EFI stub, code0 > should be replaced with "MZ" magic string and res4(at offset 0x3c) > should point to the rest of the PE/COFF header (which will be added > during EFI support). > > Tested on both QEMU and HiFive Unleashed using OpenSBI + U-Boot + Linux. Thanks Atish, happy to have this support that makes the boot process more straightforward. Tested on HiFive Unleashed using OpenSBI + U-Boot v2019.07-rc2 + Linux. > > Signed-off-by: Atish Patra > Reviewed-by: Karsten Merker > Tested-by: Karsten Merker (QEMU+OpenSBI+U-Boot) Tested-by: Loys Ollivier
