diff mbox series

[v7,5/9] RISC-V: Add PE/COFF header for EFI stub

Message ID 20200828172036.8056-6-atish.patra@wdc.com
State Accepted
Commit cb7d2dd5612a77a2597c00fce770a52c921e2ea5
Headers show
Series [v7,1/9] RISC-V: Move DT mapping outof fixmap | expand

Commit Message

Atish Patra Aug. 28, 2020, 5:20 p.m. UTC
Linux kernel Image can appear as an EFI application With appropriate
PE/COFF header fields in the beginning of the Image header. An EFI
application loader can directly load a Linux kernel Image and an EFI
stub residing in kernel can boot Linux kernel directly.

Add the necessary PE/COFF header.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Link: https://lore.kernel.org/r/20200421033336.9663-3-atish.patra@wdc.com
[ardb: - use C prefix for c.li to ensure the expected opcode is emitted
       - align all image sections according to PE/COFF section alignment ]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
---
 arch/riscv/include/asm/sections.h |  13 ++++
 arch/riscv/kernel/Makefile        |   4 ++
 arch/riscv/kernel/efi-header.S    | 104 ++++++++++++++++++++++++++++++
 arch/riscv/kernel/head.S          |  16 +++++
 arch/riscv/kernel/image-vars.h    |  51 +++++++++++++++
 arch/riscv/kernel/vmlinux.lds.S   |  22 ++++++-
 6 files changed, 208 insertions(+), 2 deletions(-)
 create mode 100644 arch/riscv/include/asm/sections.h
 create mode 100644 arch/riscv/kernel/efi-header.S
 create mode 100644 arch/riscv/kernel/image-vars.h

Comments

Ard Biesheuvel Sept. 11, 2020, 1:09 p.m. UTC | #1
On Fri, 28 Aug 2020 at 20:20, Atish Patra <atish.patra@wdc.com> wrote:
>
> Linux kernel Image can appear as an EFI application With appropriate
> PE/COFF header fields in the beginning of the Image header. An EFI
> application loader can directly load a Linux kernel Image and an EFI
> stub residing in kernel can boot Linux kernel directly.
>
> Add the necessary PE/COFF header.
>
> Signed-off-by: Atish Patra <atish.patra@wdc.com>
> Link: https://lore.kernel.org/r/20200421033336.9663-3-atish.patra@wdc.com
> [ardb: - use C prefix for c.li to ensure the expected opcode is emitted
>        - align all image sections according to PE/COFF section alignment ]
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> Reviewed-by: Anup Patel <anup@brainfault.org>

Since you need to respin this anyway, one comment below on a thing
that I spotted while revisiting these patches.

> ---
>  arch/riscv/include/asm/sections.h |  13 ++++
>  arch/riscv/kernel/Makefile        |   4 ++
>  arch/riscv/kernel/efi-header.S    | 104 ++++++++++++++++++++++++++++++
>  arch/riscv/kernel/head.S          |  16 +++++
>  arch/riscv/kernel/image-vars.h    |  51 +++++++++++++++
>  arch/riscv/kernel/vmlinux.lds.S   |  22 ++++++-
>  6 files changed, 208 insertions(+), 2 deletions(-)
>  create mode 100644 arch/riscv/include/asm/sections.h
>  create mode 100644 arch/riscv/kernel/efi-header.S
>  create mode 100644 arch/riscv/kernel/image-vars.h
>
> diff --git a/arch/riscv/include/asm/sections.h b/arch/riscv/include/asm/sections.h
> new file mode 100644
> index 000000000000..3a9971b1210f
> --- /dev/null
> +++ b/arch/riscv/include/asm/sections.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2020 Western Digital Corporation or its affiliates.
> + */
> +#ifndef __ASM_SECTIONS_H
> +#define __ASM_SECTIONS_H
> +
> +#include <asm-generic/sections.h>
> +
> +extern char _start[];
> +extern char _start_kernel[];
> +
> +#endif /* __ASM_SECTIONS_H */
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index dc93710f0b2f..41e3895a3192 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -31,6 +31,10 @@ obj-y        += cacheinfo.o
>  obj-y  += patch.o
>  obj-$(CONFIG_MMU) += vdso.o vdso/
>
> +OBJCOPYFLAGS := --prefix-symbols=__efistub_
> +$(obj)/%.stub.o: $(obj)/%.o FORCE
> +       $(call if_changed,objcopy)
> +
>  obj-$(CONFIG_RISCV_M_MODE)     += traps_misaligned.o
>  obj-$(CONFIG_FPU)              += fpu.o
>  obj-$(CONFIG_SMP)              += smpboot.o
> diff --git a/arch/riscv/kernel/efi-header.S b/arch/riscv/kernel/efi-header.S
> new file mode 100644
> index 000000000000..822b4c9ff2bb
> --- /dev/null
> +++ b/arch/riscv/kernel/efi-header.S
> @@ -0,0 +1,104 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2020 Western Digital Corporation or its affiliates.
> + * Adapted from arch/arm64/kernel/efi-header.S
> + */
> +
> +#include <linux/pe.h>
> +#include <linux/sizes.h>
> +
> +       .macro  __EFI_PE_HEADER
> +       .long   PE_MAGIC
> +coff_header:
> +#ifdef CONFIG_64BIT
> +       .short  IMAGE_FILE_MACHINE_RISCV64              // Machine
> +#else
> +       .short  IMAGE_FILE_MACHINE_RISCV32              // Machine
> +#endif
> +       .short  section_count                           // NumberOfSections
> +       .long   0                                       // TimeDateStamp
> +       .long   0                                       // PointerToSymbolTable
> +       .long   0                                       // NumberOfSymbols
> +       .short  section_table - optional_header         // SizeOfOptionalHeader
> +       .short  IMAGE_FILE_DEBUG_STRIPPED | \
> +               IMAGE_FILE_EXECUTABLE_IMAGE | \
> +               IMAGE_FILE_LINE_NUMS_STRIPPED           // Characteristics
> +
> +optional_header:
> +       .short  PE_OPT_MAGIC_PE32PLUS                   // PE32+ format

Are you sure both riscv32 and riscv64 use PE32+? IIUC, 32-bit
architectures use PE32 not PE32+ (but I could be wrong)

> +       .byte   0x02                                    // MajorLinkerVersion
> +       .byte   0x14                                    // MinorLinkerVersion
> +       .long   __pecoff_text_end - efi_header_end      // SizeOfCode
> +       .long   __pecoff_data_virt_size                 // SizeOfInitializedData
> +       .long   0                                       // SizeOfUninitializedData
> +       .long   __efistub_efi_pe_entry - _start         // AddressOfEntryPoint
> +       .long   efi_header_end - _start                 // BaseOfCode
> +
> +extra_header_fields:
> +       .quad   0                                       // ImageBase
> +       .long   PECOFF_SECTION_ALIGNMENT                // SectionAlignment
> +       .long   PECOFF_FILE_ALIGNMENT                   // FileAlignment
> +       .short  0                                       // MajorOperatingSystemVersion
> +       .short  0                                       // MinorOperatingSystemVersion
> +       .short  LINUX_EFISTUB_MAJOR_VERSION             // MajorImageVersion
> +       .short  LINUX_EFISTUB_MINOR_VERSION             // MinorImageVersion
> +       .short  0                                       // MajorSubsystemVersion
> +       .short  0                                       // MinorSubsystemVersion
> +       .long   0                                       // Win32VersionValue
> +
> +       .long   _end - _start                           // SizeOfImage
> +
> +       // Everything before the kernel image is considered part of the header
> +       .long   efi_header_end - _start                 // SizeOfHeaders
> +       .long   0                                       // CheckSum
> +       .short  IMAGE_SUBSYSTEM_EFI_APPLICATION         // Subsystem
> +       .short  0                                       // DllCharacteristics
> +       .quad   0                                       // SizeOfStackReserve
> +       .quad   0                                       // SizeOfStackCommit
> +       .quad   0                                       // SizeOfHeapReserve
> +       .quad   0                                       // SizeOfHeapCommit
> +       .long   0                                       // LoaderFlags
> +       .long   (section_table - .) / 8                 // NumberOfRvaAndSizes
> +
> +       .quad   0                                       // ExportTable
> +       .quad   0                                       // ImportTable
> +       .quad   0                                       // ResourceTable
> +       .quad   0                                       // ExceptionTable
> +       .quad   0                                       // CertificationTable
> +       .quad   0                                       // BaseRelocationTable
> +
> +       // Section table
> +section_table:
> +       .ascii  ".text\0\0\0"
> +       .long   __pecoff_text_end - efi_header_end      // VirtualSize
> +       .long   efi_header_end - _start                 // VirtualAddress
> +       .long   __pecoff_text_end - efi_header_end      // SizeOfRawData
> +       .long   efi_header_end - _start                 // PointerToRawData
> +
> +       .long   0                                       // PointerToRelocations
> +       .long   0                                       // PointerToLineNumbers
> +       .short  0                                       // NumberOfRelocations
> +       .short  0                                       // NumberOfLineNumbers
> +       .long   IMAGE_SCN_CNT_CODE | \
> +               IMAGE_SCN_MEM_READ | \
> +               IMAGE_SCN_MEM_EXECUTE                   // Characteristics
> +
> +       .ascii  ".data\0\0\0"
> +       .long   __pecoff_data_virt_size                 // VirtualSize
> +       .long   __pecoff_text_end - _start              // VirtualAddress
> +       .long   __pecoff_data_raw_size                  // SizeOfRawData
> +       .long   __pecoff_text_end - _start              // PointerToRawData
> +
> +       .long   0                                       // PointerToRelocations
> +       .long   0                                       // PointerToLineNumbers
> +       .short  0                                       // NumberOfRelocations
> +       .short  0                                       // NumberOfLineNumbers
> +       .long   IMAGE_SCN_CNT_INITIALIZED_DATA | \
> +               IMAGE_SCN_MEM_READ | \
> +               IMAGE_SCN_MEM_WRITE                     // Characteristics
> +
> +       .set    section_count, (. - section_table) / 40
> +
> +       .balign 0x1000
> +efi_header_end:
> +       .endm
> diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
> index c6a37e8231a8..3631147732ee 100644
> --- a/arch/riscv/kernel/head.S
> +++ b/arch/riscv/kernel/head.S
> @@ -13,6 +13,7 @@
>  #include <asm/csr.h>
>  #include <asm/hwcap.h>
>  #include <asm/image.h>
> +#include "efi-header.S"
>
>  __HEAD
>  ENTRY(_start)
> @@ -22,10 +23,18 @@ ENTRY(_start)
>          * Do not modify it without modifying the structure and all bootloaders
>          * that expects this header format!!
>          */
> +#ifdef CONFIG_EFI
> +       /*
> +        * This instruction decodes to "MZ" ASCII required by UEFI.
> +        */
> +       c.li s4,-13
> +       j _start_kernel
> +#else
>         /* jump to start kernel */
>         j _start_kernel
>         /* reserved */
>         .word 0
> +#endif
>         .balign 8
>  #if __riscv_xlen == 64
>         /* Image load offset(2MB) from start of RAM */
> @@ -43,7 +52,14 @@ ENTRY(_start)
>         .ascii RISCV_IMAGE_MAGIC
>         .balign 4
>         .ascii RISCV_IMAGE_MAGIC2
> +#ifdef CONFIG_EFI
> +       .word pe_head_start - _start
> +pe_head_start:
> +
> +       __EFI_PE_HEADER
> +#else
>         .word 0
> +#endif
>
>  .align 2
>  #ifdef CONFIG_MMU
> diff --git a/arch/riscv/kernel/image-vars.h b/arch/riscv/kernel/image-vars.h
> new file mode 100644
> index 000000000000..8c212efb37a6
> --- /dev/null
> +++ b/arch/riscv/kernel/image-vars.h
> @@ -0,0 +1,51 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2020 Western Digital Corporation or its affiliates.
> + * Linker script variables to be set after section resolution, as
> + * ld.lld does not like variables assigned before SECTIONS is processed.
> + * Based on arch/arm64/kerne/image-vars.h
> + */
> +#ifndef __RISCV_KERNEL_IMAGE_VARS_H
> +#define __RISCV_KERNEL_IMAGE_VARS_H
> +
> +#ifndef LINKER_SCRIPT
> +#error This file should only be included in vmlinux.lds.S
> +#endif
> +
> +#ifdef CONFIG_EFI
> +
> +/*
> + * The EFI stub has its own symbol namespace prefixed by __efistub_, to
> + * isolate it from the kernel proper. The following symbols are legally
> + * accessed by the stub, so provide some aliases to make them accessible.
> + * Only include data symbols here, or text symbols of functions that are
> + * guaranteed to be safe when executed at another offset than they were
> + * linked at. The routines below are all implemented in assembler in a
> + * position independent manner
> + */
> +__efistub_memcmp               = memcmp;
> +__efistub_memchr               = memchr;
> +__efistub_memcpy               = memcpy;
> +__efistub_memmove              = memmove;
> +__efistub_memset               = memset;
> +__efistub_strlen               = strlen;
> +__efistub_strnlen              = strnlen;
> +__efistub_strcmp               = strcmp;
> +__efistub_strncmp              = strncmp;
> +__efistub_strrchr              = strrchr;
> +
> +#ifdef CONFIG_KASAN
> +__efistub___memcpy             = memcpy;
> +__efistub___memmove            = memmove;
> +__efistub___memset             = memset;
> +#endif
> +
> +__efistub__start               = _start;
> +__efistub__start_kernel                = _start_kernel;
> +__efistub__end                 = _end;
> +__efistub__edata               = _edata;
> +__efistub_screen_info          = screen_info;
> +
> +#endif
> +
> +#endif /* __RISCV_KERNEL_IMAGE_VARS_H */
> diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
> index f3586e31ed1e..6dcf790282dd 100644
> --- a/arch/riscv/kernel/vmlinux.lds.S
> +++ b/arch/riscv/kernel/vmlinux.lds.S
> @@ -10,6 +10,7 @@
>  #include <asm/cache.h>
>  #include <asm/thread_info.h>
>  #include <asm/set_memory.h>
> +#include "image-vars.h"
>
>  #include <linux/sizes.h>
>  OUTPUT_ARCH(riscv)
> @@ -17,6 +18,9 @@ ENTRY(_start)
>
>  jiffies = jiffies_64;
>
> +PECOFF_SECTION_ALIGNMENT = 0x1000;
> +PECOFF_FILE_ALIGNMENT = 0x200;
> +
>  SECTIONS
>  {
>         /* Beginning of code and text segment */
> @@ -76,6 +80,10 @@ SECTIONS
>
>         EXCEPTION_TABLE(0x10)
>
> +#ifdef CONFIG_EFI
> +       . = ALIGN(PECOFF_SECTION_ALIGNMENT);
> +       __pecoff_text_end = .;
> +#endif
>         . = ALIGN(SECTION_ALIGN);
>         _data = .;
>
> @@ -83,16 +91,26 @@ SECTIONS
>         .sdata : {
>                 __global_pointer$ = . + 0x800;
>                 *(.sdata*)
> -               /* End of data section */
> -               _edata = .;
>         }
>
> +#ifdef CONFIG_EFI
> +       .pecoff_edata_padding : { BYTE(0); . = ALIGN(PECOFF_FILE_ALIGNMENT); }
> +       __pecoff_data_raw_size = ABSOLUTE(. - __pecoff_text_end);
> +#endif
> +
> +       /* End of data section */
> +       _edata = .;
> +
>         BSS_SECTION(PAGE_SIZE, PAGE_SIZE, 0)
>
>         .rel.dyn : {
>                 *(.rel.dyn*)
>         }
>
> +#ifdef CONFIG_EFI
> +       . = ALIGN(PECOFF_SECTION_ALIGNMENT);
> +       __pecoff_data_virt_size = ABSOLUTE(. - __pecoff_text_end);
> +#endif
>         _end = .;
>
>         STABS_DEBUG
> --
> 2.24.0
>
Ard Biesheuvel Sept. 14, 2020, 6:32 p.m. UTC | #2
On Sat, 12 Sep 2020 at 05:04, Atish Patra <atishp@atishpatra.org> wrote:
>
> On Fri, Sep 11, 2020 at 6:09 AM Ard Biesheuvel <ardb@kernel.org> wrote:
> >
> > On Fri, 28 Aug 2020 at 20:20, Atish Patra <atish.patra@wdc.com> wrote:
> > >
> > > Linux kernel Image can appear as an EFI application With appropriate
> > > PE/COFF header fields in the beginning of the Image header. An EFI
> > > application loader can directly load a Linux kernel Image and an EFI
> > > stub residing in kernel can boot Linux kernel directly.
> > >
> > > Add the necessary PE/COFF header.
> > >
> > > Signed-off-by: Atish Patra <atish.patra@wdc.com>
> > > Link: https://lore.kernel.org/r/20200421033336.9663-3-atish.patra@wdc.com
> > > [ardb: - use C prefix for c.li to ensure the expected opcode is emitted
> > >        - align all image sections according to PE/COFF section alignment ]
> > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> > > Reviewed-by: Anup Patel <anup@brainfault.org>
> >
> > Since you need to respin this anyway, one comment below on a thing
> > that I spotted while revisiting these patches.
> >
> > > ---
> > >  arch/riscv/include/asm/sections.h |  13 ++++
> > >  arch/riscv/kernel/Makefile        |   4 ++
> > >  arch/riscv/kernel/efi-header.S    | 104 ++++++++++++++++++++++++++++++
> > >  arch/riscv/kernel/head.S          |  16 +++++
> > >  arch/riscv/kernel/image-vars.h    |  51 +++++++++++++++
> > >  arch/riscv/kernel/vmlinux.lds.S   |  22 ++++++-
> > >  6 files changed, 208 insertions(+), 2 deletions(-)
> > >  create mode 100644 arch/riscv/include/asm/sections.h
> > >  create mode 100644 arch/riscv/kernel/efi-header.S
> > >  create mode 100644 arch/riscv/kernel/image-vars.h
> > >
> > > diff --git a/arch/riscv/include/asm/sections.h b/arch/riscv/include/asm/sections.h
> > > new file mode 100644
> > > index 000000000000..3a9971b1210f
> > > --- /dev/null
> > > +++ b/arch/riscv/include/asm/sections.h
> > > @@ -0,0 +1,13 @@
> > > +/* SPDX-License-Identifier: GPL-2.0-only */
> > > +/*
> > > + * Copyright (C) 2020 Western Digital Corporation or its affiliates.
> > > + */
> > > +#ifndef __ASM_SECTIONS_H
> > > +#define __ASM_SECTIONS_H
> > > +
> > > +#include <asm-generic/sections.h>
> > > +
> > > +extern char _start[];
> > > +extern char _start_kernel[];
> > > +
> > > +#endif /* __ASM_SECTIONS_H */
> > > diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> > > index dc93710f0b2f..41e3895a3192 100644
> > > --- a/arch/riscv/kernel/Makefile
> > > +++ b/arch/riscv/kernel/Makefile
> > > @@ -31,6 +31,10 @@ obj-y        += cacheinfo.o
> > >  obj-y  += patch.o
> > >  obj-$(CONFIG_MMU) += vdso.o vdso/
> > >
> > > +OBJCOPYFLAGS := --prefix-symbols=__efistub_
> > > +$(obj)/%.stub.o: $(obj)/%.o FORCE
> > > +       $(call if_changed,objcopy)
> > > +
> > >  obj-$(CONFIG_RISCV_M_MODE)     += traps_misaligned.o
> > >  obj-$(CONFIG_FPU)              += fpu.o
> > >  obj-$(CONFIG_SMP)              += smpboot.o
> > > diff --git a/arch/riscv/kernel/efi-header.S b/arch/riscv/kernel/efi-header.S
> > > new file mode 100644
> > > index 000000000000..822b4c9ff2bb
> > > --- /dev/null
> > > +++ b/arch/riscv/kernel/efi-header.S
> > > @@ -0,0 +1,104 @@
> > > +/* SPDX-License-Identifier: GPL-2.0-only */
> > > +/*
> > > + * Copyright (C) 2020 Western Digital Corporation or its affiliates.
> > > + * Adapted from arch/arm64/kernel/efi-header.S
> > > + */
> > > +
> > > +#include <linux/pe.h>
> > > +#include <linux/sizes.h>
> > > +
> > > +       .macro  __EFI_PE_HEADER
> > > +       .long   PE_MAGIC
> > > +coff_header:
> > > +#ifdef CONFIG_64BIT
> > > +       .short  IMAGE_FILE_MACHINE_RISCV64              // Machine
> > > +#else
> > > +       .short  IMAGE_FILE_MACHINE_RISCV32              // Machine
> > > +#endif
> > > +       .short  section_count                           // NumberOfSections
> > > +       .long   0                                       // TimeDateStamp
> > > +       .long   0                                       // PointerToSymbolTable
> > > +       .long   0                                       // NumberOfSymbols
> > > +       .short  section_table - optional_header         // SizeOfOptionalHeader
> > > +       .short  IMAGE_FILE_DEBUG_STRIPPED | \
> > > +               IMAGE_FILE_EXECUTABLE_IMAGE | \
> > > +               IMAGE_FILE_LINE_NUMS_STRIPPED           // Characteristics
> > > +
> > > +optional_header:
> > > +       .short  PE_OPT_MAGIC_PE32PLUS                   // PE32+ format
> >
> > Are you sure both riscv32 and riscv64 use PE32+? IIUC, 32-bit
> > architectures use PE32 not PE32+ (but I could be wrong)
> >
>
> Ahh yes. You are correct. Thanks for noticing it.
> I just followed the U-Boot implementation [1]. I will update this in
> the next revision and update the U-Boot code as well.
>
> As per the specification, we also need to add a BaseOfData[2] entry for RV32.
> Does any of the efi application loader actually use BaseOfData or can
> we set it to zero for RV32 ?
>

Just do whatever ARM and 32-bit x86 do.


> [1] https://gitlab.denx.de/u-boot/custodians/u-boot-amlogic/-/blob/u-boot-amlogic/arch/riscv/lib/crt0_riscv_efi.S#L51
> [2] https://docs.microsoft.com/en-us/windows/win32/debug/pe-format
>
> > > +       .byte   0x02                                    // MajorLinkerVersion
> > > +       .byte   0x14                                    // MinorLinkerVersion
> > > +       .long   __pecoff_text_end - efi_header_end      // SizeOfCode
> > > +       .long   __pecoff_data_virt_size                 // SizeOfInitializedData
> > > +       .long   0                                       // SizeOfUninitializedData
> > > +       .long   __efistub_efi_pe_entry - _start         // AddressOfEntryPoint
> > > +       .long   efi_header_end - _start                 // BaseOfCode
> > > +
> > > +extra_header_fields:
> > > +       .quad   0                                       // ImageBase
> > > +       .long   PECOFF_SECTION_ALIGNMENT                // SectionAlignment
> > > +       .long   PECOFF_FILE_ALIGNMENT                   // FileAlignment
> > > +       .short  0                                       // MajorOperatingSystemVersion
> > > +       .short  0                                       // MinorOperatingSystemVersion
> > > +       .short  LINUX_EFISTUB_MAJOR_VERSION             // MajorImageVersion
> > > +       .short  LINUX_EFISTUB_MINOR_VERSION             // MinorImageVersion
> > > +       .short  0                                       // MajorSubsystemVersion
> > > +       .short  0                                       // MinorSubsystemVersion
> > > +       .long   0                                       // Win32VersionValue
> > > +
> > > +       .long   _end - _start                           // SizeOfImage
> > > +
> > > +       // Everything before the kernel image is considered part of the header
> > > +       .long   efi_header_end - _start                 // SizeOfHeaders
> > > +       .long   0                                       // CheckSum
> > > +       .short  IMAGE_SUBSYSTEM_EFI_APPLICATION         // Subsystem
> > > +       .short  0                                       // DllCharacteristics
> > > +       .quad   0                                       // SizeOfStackReserve
> > > +       .quad   0                                       // SizeOfStackCommit
> > > +       .quad   0                                       // SizeOfHeapReserve
> > > +       .quad   0                                       // SizeOfHeapCommit
> > > +       .long   0                                       // LoaderFlags
> > > +       .long   (section_table - .) / 8                 // NumberOfRvaAndSizes
> > > +
> > > +       .quad   0                                       // ExportTable
> > > +       .quad   0                                       // ImportTable
> > > +       .quad   0                                       // ResourceTable
> > > +       .quad   0                                       // ExceptionTable
> > > +       .quad   0                                       // CertificationTable
> > > +       .quad   0                                       // BaseRelocationTable
> > > +
> > > +       // Section table
> > > +section_table:
> > > +       .ascii  ".text\0\0\0"
> > > +       .long   __pecoff_text_end - efi_header_end      // VirtualSize
> > > +       .long   efi_header_end - _start                 // VirtualAddress
> > > +       .long   __pecoff_text_end - efi_header_end      // SizeOfRawData
> > > +       .long   efi_header_end - _start                 // PointerToRawData
> > > +
> > > +       .long   0                                       // PointerToRelocations
> > > +       .long   0                                       // PointerToLineNumbers
> > > +       .short  0                                       // NumberOfRelocations
> > > +       .short  0                                       // NumberOfLineNumbers
> > > +       .long   IMAGE_SCN_CNT_CODE | \
> > > +               IMAGE_SCN_MEM_READ | \
> > > +               IMAGE_SCN_MEM_EXECUTE                   // Characteristics
> > > +
> > > +       .ascii  ".data\0\0\0"
> > > +       .long   __pecoff_data_virt_size                 // VirtualSize
> > > +       .long   __pecoff_text_end - _start              // VirtualAddress
> > > +       .long   __pecoff_data_raw_size                  // SizeOfRawData
> > > +       .long   __pecoff_text_end - _start              // PointerToRawData
> > > +
> > > +       .long   0                                       // PointerToRelocations
> > > +       .long   0                                       // PointerToLineNumbers
> > > +       .short  0                                       // NumberOfRelocations
> > > +       .short  0                                       // NumberOfLineNumbers
> > > +       .long   IMAGE_SCN_CNT_INITIALIZED_DATA | \
> > > +               IMAGE_SCN_MEM_READ | \
> > > +               IMAGE_SCN_MEM_WRITE                     // Characteristics
> > > +
> > > +       .set    section_count, (. - section_table) / 40
> > > +
> > > +       .balign 0x1000
> > > +efi_header_end:
> > > +       .endm
> > > diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
> > > index c6a37e8231a8..3631147732ee 100644
> > > --- a/arch/riscv/kernel/head.S
> > > +++ b/arch/riscv/kernel/head.S
> > > @@ -13,6 +13,7 @@
> > >  #include <asm/csr.h>
> > >  #include <asm/hwcap.h>
> > >  #include <asm/image.h>
> > > +#include "efi-header.S"
> > >
> > >  __HEAD
> > >  ENTRY(_start)
> > > @@ -22,10 +23,18 @@ ENTRY(_start)
> > >          * Do not modify it without modifying the structure and all bootloaders
> > >          * that expects this header format!!
> > >          */
> > > +#ifdef CONFIG_EFI
> > > +       /*
> > > +        * This instruction decodes to "MZ" ASCII required by UEFI.
> > > +        */
> > > +       c.li s4,-13
> > > +       j _start_kernel
> > > +#else
> > >         /* jump to start kernel */
> > >         j _start_kernel
> > >         /* reserved */
> > >         .word 0
> > > +#endif
> > >         .balign 8
> > >  #if __riscv_xlen == 64
> > >         /* Image load offset(2MB) from start of RAM */
> > > @@ -43,7 +52,14 @@ ENTRY(_start)
> > >         .ascii RISCV_IMAGE_MAGIC
> > >         .balign 4
> > >         .ascii RISCV_IMAGE_MAGIC2
> > > +#ifdef CONFIG_EFI
> > > +       .word pe_head_start - _start
> > > +pe_head_start:
> > > +
> > > +       __EFI_PE_HEADER
> > > +#else
> > >         .word 0
> > > +#endif
> > >
> > >  .align 2
> > >  #ifdef CONFIG_MMU
> > > diff --git a/arch/riscv/kernel/image-vars.h b/arch/riscv/kernel/image-vars.h
> > > new file mode 100644
> > > index 000000000000..8c212efb37a6
> > > --- /dev/null
> > > +++ b/arch/riscv/kernel/image-vars.h
> > > @@ -0,0 +1,51 @@
> > > +/* SPDX-License-Identifier: GPL-2.0-only */
> > > +/*
> > > + * Copyright (C) 2020 Western Digital Corporation or its affiliates.
> > > + * Linker script variables to be set after section resolution, as
> > > + * ld.lld does not like variables assigned before SECTIONS is processed.
> > > + * Based on arch/arm64/kerne/image-vars.h
> > > + */
> > > +#ifndef __RISCV_KERNEL_IMAGE_VARS_H
> > > +#define __RISCV_KERNEL_IMAGE_VARS_H
> > > +
> > > +#ifndef LINKER_SCRIPT
> > > +#error This file should only be included in vmlinux.lds.S
> > > +#endif
> > > +
> > > +#ifdef CONFIG_EFI
> > > +
> > > +/*
> > > + * The EFI stub has its own symbol namespace prefixed by __efistub_, to
> > > + * isolate it from the kernel proper. The following symbols are legally
> > > + * accessed by the stub, so provide some aliases to make them accessible.
> > > + * Only include data symbols here, or text symbols of functions that are
> > > + * guaranteed to be safe when executed at another offset than they were
> > > + * linked at. The routines below are all implemented in assembler in a
> > > + * position independent manner
> > > + */
> > > +__efistub_memcmp               = memcmp;
> > > +__efistub_memchr               = memchr;
> > > +__efistub_memcpy               = memcpy;
> > > +__efistub_memmove              = memmove;
> > > +__efistub_memset               = memset;
> > > +__efistub_strlen               = strlen;
> > > +__efistub_strnlen              = strnlen;
> > > +__efistub_strcmp               = strcmp;
> > > +__efistub_strncmp              = strncmp;
> > > +__efistub_strrchr              = strrchr;
> > > +
> > > +#ifdef CONFIG_KASAN
> > > +__efistub___memcpy             = memcpy;
> > > +__efistub___memmove            = memmove;
> > > +__efistub___memset             = memset;
> > > +#endif
> > > +
> > > +__efistub__start               = _start;
> > > +__efistub__start_kernel                = _start_kernel;
> > > +__efistub__end                 = _end;
> > > +__efistub__edata               = _edata;
> > > +__efistub_screen_info          = screen_info;
> > > +
> > > +#endif
> > > +
> > > +#endif /* __RISCV_KERNEL_IMAGE_VARS_H */
> > > diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
> > > index f3586e31ed1e..6dcf790282dd 100644
> > > --- a/arch/riscv/kernel/vmlinux.lds.S
> > > +++ b/arch/riscv/kernel/vmlinux.lds.S
> > > @@ -10,6 +10,7 @@
> > >  #include <asm/cache.h>
> > >  #include <asm/thread_info.h>
> > >  #include <asm/set_memory.h>
> > > +#include "image-vars.h"
> > >
> > >  #include <linux/sizes.h>
> > >  OUTPUT_ARCH(riscv)
> > > @@ -17,6 +18,9 @@ ENTRY(_start)
> > >
> > >  jiffies = jiffies_64;
> > >
> > > +PECOFF_SECTION_ALIGNMENT = 0x1000;
> > > +PECOFF_FILE_ALIGNMENT = 0x200;
> > > +
> > >  SECTIONS
> > >  {
> > >         /* Beginning of code and text segment */
> > > @@ -76,6 +80,10 @@ SECTIONS
> > >
> > >         EXCEPTION_TABLE(0x10)
> > >
> > > +#ifdef CONFIG_EFI
> > > +       . = ALIGN(PECOFF_SECTION_ALIGNMENT);
> > > +       __pecoff_text_end = .;
> > > +#endif
> > >         . = ALIGN(SECTION_ALIGN);
> > >         _data = .;
> > >
> > > @@ -83,16 +91,26 @@ SECTIONS
> > >         .sdata : {
> > >                 __global_pointer$ = . + 0x800;
> > >                 *(.sdata*)
> > > -               /* End of data section */
> > > -               _edata = .;
> > >         }
> > >
> > > +#ifdef CONFIG_EFI
> > > +       .pecoff_edata_padding : { BYTE(0); . = ALIGN(PECOFF_FILE_ALIGNMENT); }
> > > +       __pecoff_data_raw_size = ABSOLUTE(. - __pecoff_text_end);
> > > +#endif
> > > +
> > > +       /* End of data section */
> > > +       _edata = .;
> > > +
> > >         BSS_SECTION(PAGE_SIZE, PAGE_SIZE, 0)
> > >
> > >         .rel.dyn : {
> > >                 *(.rel.dyn*)
> > >         }
> > >
> > > +#ifdef CONFIG_EFI
> > > +       . = ALIGN(PECOFF_SECTION_ALIGNMENT);
> > > +       __pecoff_data_virt_size = ABSOLUTE(. - __pecoff_text_end);
> > > +#endif
> > >         _end = .;
> > >
> > >         STABS_DEBUG
> > > --
> > > 2.24.0
> > >
> >
> > _______________________________________________
> > linux-riscv mailing list
> > linux-riscv@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-riscv
>
>
>
> --
> Regards,
> Atish
diff mbox series

Patch

diff --git a/arch/riscv/include/asm/sections.h b/arch/riscv/include/asm/sections.h
new file mode 100644
index 000000000000..3a9971b1210f
--- /dev/null
+++ b/arch/riscv/include/asm/sections.h
@@ -0,0 +1,13 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ */
+#ifndef __ASM_SECTIONS_H
+#define __ASM_SECTIONS_H
+
+#include <asm-generic/sections.h>
+
+extern char _start[];
+extern char _start_kernel[];
+
+#endif /* __ASM_SECTIONS_H */
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index dc93710f0b2f..41e3895a3192 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -31,6 +31,10 @@  obj-y	+= cacheinfo.o
 obj-y	+= patch.o
 obj-$(CONFIG_MMU) += vdso.o vdso/
 
+OBJCOPYFLAGS := --prefix-symbols=__efistub_
+$(obj)/%.stub.o: $(obj)/%.o FORCE
+	$(call if_changed,objcopy)
+
 obj-$(CONFIG_RISCV_M_MODE)	+= traps_misaligned.o
 obj-$(CONFIG_FPU)		+= fpu.o
 obj-$(CONFIG_SMP)		+= smpboot.o
diff --git a/arch/riscv/kernel/efi-header.S b/arch/riscv/kernel/efi-header.S
new file mode 100644
index 000000000000..822b4c9ff2bb
--- /dev/null
+++ b/arch/riscv/kernel/efi-header.S
@@ -0,0 +1,104 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ * Adapted from arch/arm64/kernel/efi-header.S
+ */
+
+#include <linux/pe.h>
+#include <linux/sizes.h>
+
+	.macro	__EFI_PE_HEADER
+	.long	PE_MAGIC
+coff_header:
+#ifdef CONFIG_64BIT
+	.short	IMAGE_FILE_MACHINE_RISCV64		// Machine
+#else
+	.short	IMAGE_FILE_MACHINE_RISCV32		// Machine
+#endif
+	.short	section_count				// NumberOfSections
+	.long	0 					// TimeDateStamp
+	.long	0					// PointerToSymbolTable
+	.long	0					// NumberOfSymbols
+	.short	section_table - optional_header		// SizeOfOptionalHeader
+	.short	IMAGE_FILE_DEBUG_STRIPPED | \
+		IMAGE_FILE_EXECUTABLE_IMAGE | \
+		IMAGE_FILE_LINE_NUMS_STRIPPED		// Characteristics
+
+optional_header:
+	.short	PE_OPT_MAGIC_PE32PLUS			// PE32+ format
+	.byte	0x02					// MajorLinkerVersion
+	.byte	0x14					// MinorLinkerVersion
+	.long	__pecoff_text_end - efi_header_end	// SizeOfCode
+	.long	__pecoff_data_virt_size			// SizeOfInitializedData
+	.long	0					// SizeOfUninitializedData
+	.long	__efistub_efi_pe_entry - _start		// AddressOfEntryPoint
+	.long	efi_header_end - _start			// BaseOfCode
+
+extra_header_fields:
+	.quad	0					// ImageBase
+	.long	PECOFF_SECTION_ALIGNMENT		// SectionAlignment
+	.long	PECOFF_FILE_ALIGNMENT			// FileAlignment
+	.short	0					// MajorOperatingSystemVersion
+	.short	0					// MinorOperatingSystemVersion
+	.short	LINUX_EFISTUB_MAJOR_VERSION		// MajorImageVersion
+	.short	LINUX_EFISTUB_MINOR_VERSION		// MinorImageVersion
+	.short	0					// MajorSubsystemVersion
+	.short	0					// MinorSubsystemVersion
+	.long	0					// Win32VersionValue
+
+	.long	_end - _start				// SizeOfImage
+
+	// Everything before the kernel image is considered part of the header
+	.long	efi_header_end - _start			// SizeOfHeaders
+	.long	0					// CheckSum
+	.short	IMAGE_SUBSYSTEM_EFI_APPLICATION		// Subsystem
+	.short	0					// DllCharacteristics
+	.quad	0					// SizeOfStackReserve
+	.quad	0					// SizeOfStackCommit
+	.quad	0					// SizeOfHeapReserve
+	.quad	0					// SizeOfHeapCommit
+	.long	0					// LoaderFlags
+	.long	(section_table - .) / 8			// NumberOfRvaAndSizes
+
+	.quad	0					// ExportTable
+	.quad	0					// ImportTable
+	.quad	0					// ResourceTable
+	.quad	0					// ExceptionTable
+	.quad	0					// CertificationTable
+	.quad	0					// BaseRelocationTable
+
+	// Section table
+section_table:
+	.ascii	".text\0\0\0"
+	.long	__pecoff_text_end - efi_header_end	// VirtualSize
+	.long	efi_header_end - _start			// VirtualAddress
+	.long	__pecoff_text_end - efi_header_end	// SizeOfRawData
+	.long	efi_header_end - _start			// PointerToRawData
+
+	.long	0					// PointerToRelocations
+	.long	0					// PointerToLineNumbers
+	.short	0					// NumberOfRelocations
+	.short	0					// NumberOfLineNumbers
+	.long	IMAGE_SCN_CNT_CODE | \
+		IMAGE_SCN_MEM_READ | \
+		IMAGE_SCN_MEM_EXECUTE			// Characteristics
+
+	.ascii	".data\0\0\0"
+	.long	__pecoff_data_virt_size			// VirtualSize
+	.long	__pecoff_text_end - _start		// VirtualAddress
+	.long	__pecoff_data_raw_size			// SizeOfRawData
+	.long	__pecoff_text_end - _start		// PointerToRawData
+
+	.long	0					// PointerToRelocations
+	.long	0					// PointerToLineNumbers
+	.short	0					// NumberOfRelocations
+	.short	0					// NumberOfLineNumbers
+	.long	IMAGE_SCN_CNT_INITIALIZED_DATA | \
+		IMAGE_SCN_MEM_READ | \
+		IMAGE_SCN_MEM_WRITE			// Characteristics
+
+	.set	section_count, (. - section_table) / 40
+
+	.balign	0x1000
+efi_header_end:
+	.endm
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index c6a37e8231a8..3631147732ee 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -13,6 +13,7 @@ 
 #include <asm/csr.h>
 #include <asm/hwcap.h>
 #include <asm/image.h>
+#include "efi-header.S"
 
 __HEAD
 ENTRY(_start)
@@ -22,10 +23,18 @@  ENTRY(_start)
 	 * Do not modify it without modifying the structure and all bootloaders
 	 * that expects this header format!!
 	 */
+#ifdef CONFIG_EFI
+	/*
+	 * This instruction decodes to "MZ" ASCII required by UEFI.
+	 */
+	c.li s4,-13
+	j _start_kernel
+#else
 	/* jump to start kernel */
 	j _start_kernel
 	/* reserved */
 	.word 0
+#endif
 	.balign 8
 #if __riscv_xlen == 64
 	/* Image load offset(2MB) from start of RAM */
@@ -43,7 +52,14 @@  ENTRY(_start)
 	.ascii RISCV_IMAGE_MAGIC
 	.balign 4
 	.ascii RISCV_IMAGE_MAGIC2
+#ifdef CONFIG_EFI
+	.word pe_head_start - _start
+pe_head_start:
+
+	__EFI_PE_HEADER
+#else
 	.word 0
+#endif
 
 .align 2
 #ifdef CONFIG_MMU
diff --git a/arch/riscv/kernel/image-vars.h b/arch/riscv/kernel/image-vars.h
new file mode 100644
index 000000000000..8c212efb37a6
--- /dev/null
+++ b/arch/riscv/kernel/image-vars.h
@@ -0,0 +1,51 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ * Linker script variables to be set after section resolution, as
+ * ld.lld does not like variables assigned before SECTIONS is processed.
+ * Based on arch/arm64/kerne/image-vars.h
+ */
+#ifndef __RISCV_KERNEL_IMAGE_VARS_H
+#define __RISCV_KERNEL_IMAGE_VARS_H
+
+#ifndef LINKER_SCRIPT
+#error This file should only be included in vmlinux.lds.S
+#endif
+
+#ifdef CONFIG_EFI
+
+/*
+ * The EFI stub has its own symbol namespace prefixed by __efistub_, to
+ * isolate it from the kernel proper. The following symbols are legally
+ * accessed by the stub, so provide some aliases to make them accessible.
+ * Only include data symbols here, or text symbols of functions that are
+ * guaranteed to be safe when executed at another offset than they were
+ * linked at. The routines below are all implemented in assembler in a
+ * position independent manner
+ */
+__efistub_memcmp		= memcmp;
+__efistub_memchr		= memchr;
+__efistub_memcpy		= memcpy;
+__efistub_memmove		= memmove;
+__efistub_memset		= memset;
+__efistub_strlen		= strlen;
+__efistub_strnlen		= strnlen;
+__efistub_strcmp		= strcmp;
+__efistub_strncmp		= strncmp;
+__efistub_strrchr		= strrchr;
+
+#ifdef CONFIG_KASAN
+__efistub___memcpy		= memcpy;
+__efistub___memmove		= memmove;
+__efistub___memset		= memset;
+#endif
+
+__efistub__start		= _start;
+__efistub__start_kernel		= _start_kernel;
+__efistub__end			= _end;
+__efistub__edata		= _edata;
+__efistub_screen_info		= screen_info;
+
+#endif
+
+#endif /* __RISCV_KERNEL_IMAGE_VARS_H */
diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
index f3586e31ed1e..6dcf790282dd 100644
--- a/arch/riscv/kernel/vmlinux.lds.S
+++ b/arch/riscv/kernel/vmlinux.lds.S
@@ -10,6 +10,7 @@ 
 #include <asm/cache.h>
 #include <asm/thread_info.h>
 #include <asm/set_memory.h>
+#include "image-vars.h"
 
 #include <linux/sizes.h>
 OUTPUT_ARCH(riscv)
@@ -17,6 +18,9 @@  ENTRY(_start)
 
 jiffies = jiffies_64;
 
+PECOFF_SECTION_ALIGNMENT = 0x1000;
+PECOFF_FILE_ALIGNMENT = 0x200;
+
 SECTIONS
 {
 	/* Beginning of code and text segment */
@@ -76,6 +80,10 @@  SECTIONS
 
 	EXCEPTION_TABLE(0x10)
 
+#ifdef CONFIG_EFI
+	. = ALIGN(PECOFF_SECTION_ALIGNMENT);
+	__pecoff_text_end = .;
+#endif
 	. = ALIGN(SECTION_ALIGN);
 	_data = .;
 
@@ -83,16 +91,26 @@  SECTIONS
 	.sdata : {
 		__global_pointer$ = . + 0x800;
 		*(.sdata*)
-		/* End of data section */
-		_edata = .;
 	}
 
+#ifdef CONFIG_EFI
+	.pecoff_edata_padding : { BYTE(0); . = ALIGN(PECOFF_FILE_ALIGNMENT); }
+	__pecoff_data_raw_size = ABSOLUTE(. - __pecoff_text_end);
+#endif
+
+	/* End of data section */
+	_edata = .;
+
 	BSS_SECTION(PAGE_SIZE, PAGE_SIZE, 0)
 
 	.rel.dyn : {
 		*(.rel.dyn*)
 	}
 
+#ifdef CONFIG_EFI
+	. = ALIGN(PECOFF_SECTION_ALIGNMENT);
+	__pecoff_data_virt_size = ABSOLUTE(. - __pecoff_text_end);
+#endif
 	_end = .;
 
 	STABS_DEBUG