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Re: [PATCH v4] xen/riscv: PE/COFF image header for RISC-V target



On Mon, Jul 8, 2024 at 11:32 AM Jan Beulich <jbeulich@xxxxxxxx> wrote:
>
> On 04.07.2024 19:21, Milan Đokić wrote:
> > On Wed, Jul 3, 2024 at 5:55 PM Jan Beulich <jbeulich@xxxxxxxx> wrote:
> >> On 03.07.2024 02:04, Milan Djokic wrote:
> >>> +#ifdef CONFIG_RISCV_EFI
> >>> +        /*
> >>> +         * This instruction decodes to "MZ" ASCII required by UEFI.
> >>> +         */
> >>> +        c.li s4,-13
> >>> +        c.j xen_start
> >>> +#else
> >>> +        /* jump to start kernel */
> >>> +        jal xen_start
> >>
> >> JAL, not J? Why?
> >>
> > We use jal explicitly here to highlight that we want to occupy 32 bits
> > in order to align with header format (and EFI case where we use two
> > 16-bits instructions). Although it will also work by using "j"
> > directly, it could be implicitly compressed to 16 bits (if C extension
> > is available) which would make header layout less obvious imo.
>
> According to e.g. ...
>
> >>> +#endif
> >>> +        .balign 8
> >>
> >> This won't do what you want unless "start" itself is also suitably aligned.
> >> It'll be as long as it's first in the section, but better make such 
> >> explicit.
> >>
> > I understand, we'll also explicitly align "start"
> >
> >>> +#ifdef CONFIG_RISCV_64
> >>> +        /* Image load offset(2MB) from start of RAM */
> >>> +        .quad 0x200000
> >>> +#else
> >>> +        /* Image load offset(4MB) from start of RAM */
> >>> +        .quad 0x400000
> >>> +#endif
>
> ... the #ifdef here, you aim at having code be suitable for RV32, too.
> However, JAL has a compressed form there, so its use would make things
> "less obvious" there as well. I'm inclined to say that since the
> subsequent ".balign 8" adds padding NOPs anyway, there's no real
> difference whether that adds 32 bits worth of NOPs or 48 bits. If you
> really wanted to "hide" the difference, imo ".balign 4" would be the
> way to go.
>
> In any event, if there would still be a reason to stick to JAL, you'd
> want to name the reason(s) in a code comment.
>
No specific reason to use jal from a functional point of view, just
aesthetic reasons as I mentioned in a previous comment. Also jal is
used across head.S file, so we also keep some consistency in that
manner. I just don't get the reason why "j" is more suitable as a
pseudo instruction since it also comes down to jal as a base
instruction.
Of course, we can easily switch to "j" here, just want to know why we
are doing so.

> >> What these constants derive from? I expect they aren't really "magic" .
> >>
> > These offsets are commonly used for RISCV SOCs. In general, these can
> > have different values, depending on memory layout, but in order to be
> > compatible with
> > linux bootloaders we just followed the common practice.
>
> So entirely magic, really. Such imo needs commenting on.
>
Sure, we'll comment on this one.

> >>> @@ -60,6 +100,7 @@ FUNC(start)
> >>>          mv      a1, s1
> >>>
> >>>          tail    start_xen
> >>> +
> >>>  END(start)
> >>>
> >>>          .section .text, "ax", %progbits
> >>
> >> What is this hunk about?
> >>
> > Not sure which part of the code you refer to here. This section is
> > part of the original riscv implementation. We only grouped this
> > section under the new, xen_start label since we have different
> > handling for EFI and ELF formats  in the beginning of "start" function
> > before jumping to xen_start.
>
> "Hunk" is common term for a single piece of "diff" output, starting at
> the @@ line. To word it differently: What reason is there to insert a
> blank line in this very patch?
>
Sry, I haven't seen the blank line diff at all. We'll remove this one,
it was added by mistake.

> >>> --- /dev/null
> >>> +++ b/xen/include/efi/pe.h
> >>> @@ -0,0 +1,458 @@
> >>> +#ifndef __PE_H
> >>
> >> This probably wants (needs?) to gain an SPDX line.
> >>
> > Yes, it was originally taken over from the linux kernel (with some
> > modifications from our side), but we omitted the SPDX line by mistake.
> >
> >>> +#define __PE_H
> >>> +
> >>> +/*
> >>> + * Linux EFI stub v1.0 adds the following functionality:
> >>> + * - Loading initrd from the LINUX_EFI_INITRD_MEDIA_GUID device path,
> >>> + * - Loading/starting the kernel from firmware that targets a different
> >>> + *   machine type, via the entrypoint exposed in the .compat PE/COFF 
> >>> section.
> >>> + *
> >>> + * The recommended way of loading and starting v1.0 or later kernels is 
> >>> to use
> >>> + * the LoadImage() and StartImage() EFI boot services, and expose the 
> >>> initrd
> >>> + * via the LINUX_EFI_INITRD_MEDIA_GUID device path.
> >>> + *
> >>> + * Versions older than v1.0 support initrd loading via the image load 
> >>> options
> >>> + * (using initrd=, limited to the volume from which the kernel itself was
> >>> + * loaded), or via arch specific means (bootparams, DT, etc).
> >>> + *
> >>> + * On x86, LoadImage() and StartImage() can be omitted if the EFI 
> >>> handover
> >>> + * protocol is implemented, which can be inferred from the version,
> >>> + * handover_offset and xloadflags fields in the bootparams structure.
> >>> + */
> >>> +#define LINUX_EFISTUB_MAJOR_VERSION 0x1
> >>> +#define LINUX_EFISTUB_MINOR_VERSION 0x0
> >>> +
> >>> +#define MZ_MAGIC 0x5a4d /* "MZ" */
> >>> +
> >>> +#define PE_MAGIC              0x00004550 /* "PE\0\0" */
> >>> +#define PE_OPT_MAGIC_PE32     0x010b
> >>> +#define PE_OPT_MAGIC_PE32_ROM 0x0107
> >>> +#define PE_OPT_MAGIC_PE32PLUS 0x020b
> >>> +
> >>> +/* machine type */
> >>> +#define IMAGE_FILE_MACHINE_UNKNOWN   0x0000
> >>> +#define IMAGE_FILE_MACHINE_AM33      0x01d3
> >>> +#define IMAGE_FILE_MACHINE_AMD64     0x8664
> >>> +#define IMAGE_FILE_MACHINE_ARM       0x01c0
> >>> +#define IMAGE_FILE_MACHINE_ARMV7     0x01c4
> >>> +#define IMAGE_FILE_MACHINE_ARM64     0xaa64
> >>> +#define IMAGE_FILE_MACHINE_EBC       0x0ebc
> >>> +#define IMAGE_FILE_MACHINE_I386      0x014c
> >>> +#define IMAGE_FILE_MACHINE_IA64      0x0200
> >>> +#define IMAGE_FILE_MACHINE_M32R      0x9041
> >>> +#define IMAGE_FILE_MACHINE_MIPS16    0x0266
> >>> +#define IMAGE_FILE_MACHINE_MIPSFPU   0x0366
> >>> +#define IMAGE_FILE_MACHINE_MIPSFPU16 0x0466
> >>> +#define IMAGE_FILE_MACHINE_POWERPC   0x01f0
> >>> +#define IMAGE_FILE_MACHINE_POWERPCFP 0x01f1
> >>> +#define IMAGE_FILE_MACHINE_R4000     0x0166
> >>> +#define IMAGE_FILE_MACHINE_RISCV32   0x5032
> >>> +#define IMAGE_FILE_MACHINE_RISCV64   0x5064
> >>> +#define IMAGE_FILE_MACHINE_RISCV128  0x5128
> >>> +#define IMAGE_FILE_MACHINE_SH3       0x01a2
> >>> +#define IMAGE_FILE_MACHINE_SH3DSP    0x01a3
> >>> +#define IMAGE_FILE_MACHINE_SH3E      0x01a4
> >>> +#define IMAGE_FILE_MACHINE_SH4       0x01a6
> >>> +#define IMAGE_FILE_MACHINE_SH5       0x01a8
> >>> +#define IMAGE_FILE_MACHINE_THUMB     0x01c2
> >>> +#define IMAGE_FILE_MACHINE_WCEMIPSV2 0x0169
> >>> +
> >>> +/* flags */
> >>> +#define IMAGE_FILE_RELOCS_STRIPPED         0x0001
> >>> +#define IMAGE_FILE_EXECUTABLE_IMAGE        0x0002
> >>> +#define IMAGE_FILE_LINE_NUMS_STRIPPED      0x0004
> >>> +#define IMAGE_FILE_LOCAL_SYMS_STRIPPED     0x0008
> >>> +#define IMAGE_FILE_AGGRESSIVE_WS_TRIM      0x0010
> >>> +#define IMAGE_FILE_LARGE_ADDRESS_AWARE     0x0020
> >>> +#define IMAGE_FILE_16BIT_MACHINE           0x0040
> >>> +#define IMAGE_FILE_BYTES_REVERSED_LO       0x0080
> >>> +#define IMAGE_FILE_32BIT_MACHINE           0x0100
> >>> +#define IMAGE_FILE_DEBUG_STRIPPED          0x0200
> >>> +#define IMAGE_FILE_REMOVABLE_RUN_FROM_SWAP 0x0400
> >>> +#define IMAGE_FILE_NET_RUN_FROM_SWAP       0x0800
> >>> +#define IMAGE_FILE_SYSTEM                  0x1000
> >>> +#define IMAGE_FILE_DLL                     0x2000
> >>> +#define IMAGE_FILE_UP_SYSTEM_ONLY          0x4000
> >>> +#define IMAGE_FILE_BYTES_REVERSED_HI       0x8000
> >>> +
> >>> +#define IMAGE_FILE_OPT_ROM_MAGIC       0x107
> >>> +#define IMAGE_FILE_OPT_PE32_MAGIC      0x10b
> >>> +#define IMAGE_FILE_OPT_PE32_PLUS_MAGIC 0x20b
> >>> +
> >>> +#define IMAGE_SUBSYSTEM_UNKNOWN                 0
> >>> +#define IMAGE_SUBSYSTEM_NATIVE                  1
> >>> +#define IMAGE_SUBSYSTEM_WINDOWS_GUI             2
> >>> +#define IMAGE_SUBSYSTEM_WINDOWS_CUI             3
> >>> +#define IMAGE_SUBSYSTEM_POSIX_CUI               7
> >>> +#define IMAGE_SUBSYSTEM_WINDOWS_CE_GUI          9
> >>> +#define IMAGE_SUBSYSTEM_EFI_APPLICATION         10
> >>> +#define IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER 11
> >>> +#define IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER      12
> >>> +#define IMAGE_SUBSYSTEM_EFI_ROM_IMAGE           13
> >>> +#define IMAGE_SUBSYSTEM_XBOX                    14
> >>> +
> >>> +#define IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE         0x0040
> >>> +#define IMAGE_DLL_CHARACTERISTICS_FORCE_INTEGRITY      0x0080
> >>> +#define IMAGE_DLL_CHARACTERISTICS_NX_COMPAT            0x0100
> >>> +#define IMAGE_DLLCHARACTERISTICS_NO_ISOLATION          0x0200
> >>> +#define IMAGE_DLLCHARACTERISTICS_NO_SEH                0x0400
> >>> +#define IMAGE_DLLCHARACTERISTICS_NO_BIND               0x0800
> >>> +#define IMAGE_DLLCHARACTERISTICS_WDM_DRIVER            0x2000
> >>> +#define IMAGE_DLLCHARACTERISTICS_TERMINAL_SERVER_AWARE 0x8000
> >>> +
> >>> +/* they actually defined 0x00000000 as well, but I think we'll skip that 
> >>> one. */
> >>> +#define IMAGE_SCN_RESERVED_0             0x00000001
> >>> +#define IMAGE_SCN_RESERVED_1             0x00000002
> >>> +#define IMAGE_SCN_RESERVED_2             0x00000004
> >>> +#define IMAGE_SCN_TYPE_NO_PAD            0x00000008 /* don't pad - 
> >>> obsolete */
> >>> +#define IMAGE_SCN_RESERVED_3             0x00000010
> >>> +#define IMAGE_SCN_CNT_CODE               0x00000020 /* .text */
> >>> +#define IMAGE_SCN_CNT_INITIALIZED_DATA   0x00000040 /* .data */
> >>> +#define IMAGE_SCN_CNT_UNINITIALIZED_DATA 0x00000080 /* .bss */
> >>> +#define IMAGE_SCN_LNK_OTHER              0x00000100 /* reserved */
> >>> +#define IMAGE_SCN_LNK_INFO               0x00000200 /* .drectve comments 
> >>> */
> >>> +#define IMAGE_SCN_RESERVED_4             0x00000400
> >>> +#define IMAGE_SCN_LNK_REMOVE             0x00000800 /* .o only - scn to 
> >>> be rm'd*/
> >>> +#define IMAGE_SCN_LNK_COMDAT             0x00001000 /* .o only - COMDAT 
> >>> data */
> >>> +#define IMAGE_SCN_RESERVED_5             0x00002000 /* spec omits this */
> >>> +#define IMAGE_SCN_RESERVED_6             0x00004000 /* spec omits this */
> >>> +#define IMAGE_SCN_GPREL                  0x00008000 /* global pointer 
> >>> referenced data */
> >>> +/* spec lists 0x20000 twice, I suspect they meant 0x10000 for one of 
> >>> them */
> >>> +#define IMAGE_SCN_MEM_PURGEABLE 0x00010000 /* reserved for "future" use 
> >>> */
> >>> +#define IMAGE_SCN_16BIT         0x00020000 /* reserved for "future" use 
> >>> */
> >>> +#define IMAGE_SCN_LOCKED        0x00040000 /* reserved for "future" use 
> >>> */
> >>> +#define IMAGE_SCN_PRELOAD       0x00080000 /* reserved for "future" use 
> >>> */
> >>> +/* and here they just stuck a 1-byte integer in the middle of a bitfield 
> >>> */
> >>> +#define IMAGE_SCN_ALIGN_1BYTES    0x00100000 /* it does what it says on 
> >>> the box */
> >>> +#define IMAGE_SCN_ALIGN_2BYTES    0x00200000
> >>> +#define IMAGE_SCN_ALIGN_4BYTES    0x00300000
> >>> +#define IMAGE_SCN_ALIGN_8BYTES    0x00400000
> >>> +#define IMAGE_SCN_ALIGN_16BYTES   0x00500000
> >>> +#define IMAGE_SCN_ALIGN_32BYTES   0x00600000
> >>> +#define IMAGE_SCN_ALIGN_64BYTES   0x00700000
> >>> +#define IMAGE_SCN_ALIGN_128BYTES  0x00800000
> >>> +#define IMAGE_SCN_ALIGN_256BYTES  0x00900000
> >>> +#define IMAGE_SCN_ALIGN_512BYTES  0x00a00000
> >>> +#define IMAGE_SCN_ALIGN_1024BYTES 0x00b00000
> >>> +#define IMAGE_SCN_ALIGN_2048BYTES 0x00c00000
> >>> +#define IMAGE_SCN_ALIGN_4096BYTES 0x00d00000
> >>> +#define IMAGE_SCN_ALIGN_8192BYTES 0x00e00000
> >>> +#define IMAGE_SCN_LNK_NRELOC_OVFL 0x01000000 /* extended relocations */
> >>> +#define IMAGE_SCN_MEM_DISCARDABLE 0x02000000 /* scn can be discarded */
> >>> +#define IMAGE_SCN_MEM_NOT_CACHED  0x04000000 /* cannot be cached */
> >>> +#define IMAGE_SCN_MEM_NOT_PAGED   0x08000000 /* not pageable */
> >>> +#define IMAGE_SCN_MEM_SHARED      0x10000000 /* can be shared */
> >>> +#define IMAGE_SCN_MEM_EXECUTE     0x20000000 /* can be executed as code 
> >>> */
> >>> +#define IMAGE_SCN_MEM_READ        0x40000000 /* readable */
> >>> +#define IMAGE_SCN_MEM_WRITE       0x80000000 /* writeable */
> >>> +
> >>> +#define IMAGE_DEBUG_TYPE_CODEVIEW 2
> >>> +
> >>> +#ifndef __ASSEMBLY__
> >>> +
> >>> +struct mz_hdr {
> >>> +    uint16_t magic;              /* MZ_MAGIC */
> >>> +    uint16_t lbsize;             /* size of last used block */
> >>> +    uint16_t blocks;             /* pages in file, 0x3 */
> >>> +    uint16_t relocs;             /* relocations */
> >>> +    uint16_t hdrsize;            /* header size in "paragraphs" */
> >>> +    uint16_t min_extra_pps;      /* .bss */
> >>> +    uint16_t max_extra_pps;      /* runtime limit for the arena size */
> >>> +    uint16_t ss;                 /* relative stack segment */
> >>> +    uint16_t sp;                 /* initial %sp register */
> >>> +    uint16_t checksum;           /* word checksum */
> >>> +    uint16_t ip;                 /* initial %ip register */
> >>> +    uint16_t cs;                 /* initial %cs relative to load segment 
> >>> */
> >>> +    uint16_t reloc_table_offset; /* offset of the first relocation */
> >>> +    uint16_t overlay_num;        /* overlay number.  set to 0. */
> >>> +    uint16_t reserved0[4];       /* reserved */
> >>> +    uint16_t oem_id;             /* oem identifier */
> >>> +    uint16_t oem_info;           /* oem specific */
> >>> +    uint16_t reserved1[10];      /* reserved */
> >>> +    uint32_t peaddr;             /* address of pe header */
> >>> +    char     message[];          /* message to print */
> >>> +};
> >>
> >> We already have an instance of this struct in common/efi/pe.c. I think
> >> it wouldn't be very desirable to have two (different) instances.
> >>
> >>> +struct mz_reloc {
> >>> +    uint16_t offset;
> >>> +    uint16_t segment;
> >>> +};
> >>
> >> We aren't going to need this anywhere, are we?
> >>
> >>> +struct pe_hdr {
> >>> +    uint32_t magic;        /* PE magic */
> >>> +    uint16_t machine;      /* machine type */
> >>> +    uint16_t sections;     /* number of sections */
> >>> +    uint32_t timestamp;    /* time_t */
> >>> +    uint32_t symbol_table; /* symbol table offset */
> >>> +    uint32_t symbols;      /* number of symbols */
> >>> +    uint16_t opt_hdr_size; /* size of optional header */
> >>> +    uint16_t flags;        /* flags */
> >>> +};
> >>
> >> And again another (different) instance of this and further struct-s
> >> already exists. Same for the section header further down.
> >>
> >>> +/* the fact that pe32 isn't padded where pe32+ is 64-bit means union 
> >>> won't
> >>> + * work right.  vomit. */
> >>
> >> Noticing here in particular, but being an issue elsewhere as well:
> >> Unless this file is to be a verbatim copy taken from somewhere (in
> >> which case it should probably be introduced in a separate commit
> >> with an Origin: tag), comments want to adhere of ./CODING_STYLE.
> >>
> >>> +struct pe32_opt_hdr {
> >>> +    /* "standard" header */
> >>> +    uint16_t magic;       /* file type */
> >>> +    uint8_t  ld_major;    /* linker major version */
> >>> +    uint8_t  ld_minor;    /* linker minor version */
> >>> +    uint32_t text_size;   /* size of text section(s) */
> >>> +    uint32_t data_size;   /* size of data section(s) */
> >>> +    uint32_t bss_size;    /* size of bss section(s) */
> >>> +    uint32_t entry_point; /* file offset of entry point */
> >>> +    uint32_t code_base;   /* relative code addr in ram */
> >>> +    uint32_t data_base;   /* relative data addr in ram */
> >>> +    /* "windows" header */
> >>> +    uint32_t image_base;     /* preferred load address */
> >>> +    uint32_t section_align;  /* alignment in bytes */
> >>> +    uint32_t file_align;     /* file alignment in bytes */
> >>> +    uint16_t os_major;       /* major OS version */
> >>> +    uint16_t os_minor;       /* minor OS version */
> >>> +    uint16_t image_major;    /* major image version */
> >>> +    uint16_t image_minor;    /* minor image version */
> >>> +    uint16_t subsys_major;   /* major subsystem version */
> >>> +    uint16_t subsys_minor;   /* minor subsystem version */
> >>> +    uint32_t win32_version;  /* reserved, must be 0 */
> >>> +    uint32_t image_size;     /* image size */
> >>> +    uint32_t header_size;    /* header size rounded up to file_align */
> >>> +    uint32_t csum;           /* checksum */
> >>> +    uint16_t subsys;         /* subsystem */
> >>> +    uint16_t dll_flags;      /* executable characteristics */
> >>> +    uint32_t stack_size_req; /* amt of stack requested */
> >>> +    uint32_t stack_size;     /* amt of stack required */
> >>> +    uint32_t heap_size_req;  /* amt of heap requested */
> >>> +    uint32_t heap_size;      /* amt of heap required */
> >>> +    uint32_t loader_flags;   /* reserved, must be 0 */
> >>> +    uint32_t data_dirs;      /* number of data dir entries */
> >>> +};
> >>> +
> >>> +struct pe32plus_opt_hdr {
> >>> +    uint16_t magic;       /* file type */
> >>> +    uint8_t  ld_major;    /* linker major version */
> >>> +    uint8_t  ld_minor;    /* linker minor version */
> >>> +    uint32_t text_size;   /* size of text section(s) */
> >>> +    uint32_t data_size;   /* size of data section(s) */
> >>> +    uint32_t bss_size;    /* size of bss section(s) */
> >>> +    uint32_t entry_point; /* file offset of entry point */
> >>> +    uint32_t code_base;   /* relative code addr in ram */
> >>> +    /* "windows" header */
> >>> +    uint64_t image_base;     /* preferred load address */
> >>> +    uint32_t section_align;  /* alignment in bytes */
> >>> +    uint32_t file_align;     /* file alignment in bytes */
> >>> +    uint16_t os_major;       /* major OS version */
> >>> +    uint16_t os_minor;       /* minor OS version */
> >>> +    uint16_t image_major;    /* major image version */
> >>> +    uint16_t image_minor;    /* minor image version */
> >>> +    uint16_t subsys_major;   /* major subsystem version */
> >>> +    uint16_t subsys_minor;   /* minor subsystem version */
> >>> +    uint32_t win32_version;  /* reserved, must be 0 */
> >>> +    uint32_t image_size;     /* image size */
> >>> +    uint32_t header_size;    /* header size rounded up to file_align */
> >>> +    uint32_t csum;           /* checksum */
> >>> +    uint16_t subsys;         /* subsystem */
> >>> +    uint16_t dll_flags;      /* executable characteristics */
> >>> +    uint64_t stack_size_req; /* amt of stack requested */
> >>> +    uint64_t stack_size;     /* amt of stack required */
> >>> +    uint64_t heap_size_req;  /* amt of heap requested */
> >>> +    uint64_t heap_size;      /* amt of heap required */
> >>> +    uint32_t loader_flags;   /* reserved, must be 0 */
> >>> +    uint32_t data_dirs;      /* number of data dir entries */
> >>> +};
> >>> +
> >>> +struct data_dirent {
> >>> +    uint32_t virtual_address; /* relative to load address */
> >>> +    uint32_t size;
> >>> +};
> >>
> >> Will we need this and ...
> >>
> >>> +struct data_directory {
> >>> +    struct data_dirent exports;          /* .edata */
> >>> +    struct data_dirent imports;          /* .idata */
> >>> +    struct data_dirent resources;        /* .rsrc */
> >>> +    struct data_dirent exceptions;       /* .pdata */
> >>> +    struct data_dirent certs;            /* certs */
> >>> +    struct data_dirent base_relocations; /* .reloc */
> >>> +    struct data_dirent debug;            /* .debug */
> >>> +    struct data_dirent arch;             /* reservered */
> >>> +    struct data_dirent global_ptr;       /* global pointer reg. Size=0 */
> >>> +    struct data_dirent tls;              /* .tls */
> >>> +    struct data_dirent load_config;      /* load configuration structure 
> >>> */
> >>> +    struct data_dirent bound_imports;    /* no idea */
> >>> +    struct data_dirent import_addrs;     /* import address table */
> >>> +    struct data_dirent delay_imports;    /* delay-load import table */
> >>> +    struct data_dirent clr_runtime_hdr;  /* .cor (object only) */
> >>> +    struct data_dirent reserved;
> >>> +};
> >>
> >> ... this?
> >>
> >>> +struct section_header {
> >>> +    char     name[8];         /* name or string tbl offset */
> >>> +    uint32_t virtual_size;    /* size of loaded section in ram */
> >>> +    uint32_t virtual_address; /* relative virtual address */
> >>> +    uint32_t raw_data_size;   /* size of the section */
> >>> +    uint32_t data_addr;       /* file pointer to first page of sec */
> >>> +    uint32_t relocs;          /* file pointer to relocation entries */
> >>> +    uint32_t line_numbers;    /* line numbers */
> >>> +    uint16_t num_relocs;      /* number of relocations */
> >>> +    uint16_t num_lin_numbers; /* COFF line count. */
> >>> +    uint32_t flags;
> >>> +};
> >>> +
> >>> +enum x64_coff_reloc_type {
> >>> +    IMAGE_REL_AMD64_ABSOLUTE = 0,
> >>> +    IMAGE_REL_AMD64_ADDR64,
> >>> +    IMAGE_REL_AMD64_ADDR32,
> >>> +    IMAGE_REL_AMD64_ADDR32N,
> >>> +    IMAGE_REL_AMD64_REL32,
> >>> +    IMAGE_REL_AMD64_REL32_1,
> >>> +    IMAGE_REL_AMD64_REL32_2,
> >>> +    IMAGE_REL_AMD64_REL32_3,
> >>> +    IMAGE_REL_AMD64_REL32_4,
> >>> +    IMAGE_REL_AMD64_REL32_5,
> >>> +    IMAGE_REL_AMD64_SECTION,
> >>> +    IMAGE_REL_AMD64_SECREL,
> >>> +    IMAGE_REL_AMD64_SECREL7,
> >>> +    IMAGE_REL_AMD64_TOKEN,
> >>> +    IMAGE_REL_AMD64_SREL32,
> >>> +    IMAGE_REL_AMD64_PAIR,
> >>> +    IMAGE_REL_AMD64_SSPAN32,
> >>> +};
> >>> +
> >>> +enum arm_coff_reloc_type {
> >>> +    IMAGE_REL_ARM_ABSOLUTE,
> >>> +    IMAGE_REL_ARM_ADDR32,
> >>> +    IMAGE_REL_ARM_ADDR32N,
> >>> +    IMAGE_REL_ARM_BRANCH2,
> >>> +    IMAGE_REL_ARM_BRANCH1,
> >>> +    IMAGE_REL_ARM_SECTION,
> >>> +    IMAGE_REL_ARM_SECREL,
> >>> +};
> >>> +
> >>> +enum sh_coff_reloc_type {
> >>> +    IMAGE_REL_SH3_ABSOLUTE,
> >>> +    IMAGE_REL_SH3_DIRECT16,
> >>> +    IMAGE_REL_SH3_DIRECT32,
> >>> +    IMAGE_REL_SH3_DIRECT8,
> >>> +    IMAGE_REL_SH3_DIRECT8_WORD,
> >>> +    IMAGE_REL_SH3_DIRECT8_LONG,
> >>> +    IMAGE_REL_SH3_DIRECT4,
> >>> +    IMAGE_REL_SH3_DIRECT4_WORD,
> >>> +    IMAGE_REL_SH3_DIRECT4_LONG,
> >>> +    IMAGE_REL_SH3_PCREL8_WORD,
> >>> +    IMAGE_REL_SH3_PCREL8_LONG,
> >>> +    IMAGE_REL_SH3_PCREL12_WORD,
> >>> +    IMAGE_REL_SH3_STARTOF_SECTION,
> >>> +    IMAGE_REL_SH3_SIZEOF_SECTION,
> >>> +    IMAGE_REL_SH3_SECTION,
> >>> +    IMAGE_REL_SH3_SECREL,
> >>> +    IMAGE_REL_SH3_DIRECT32_NB,
> >>> +    IMAGE_REL_SH3_GPREL4_LONG,
> >>> +    IMAGE_REL_SH3_TOKEN,
> >>> +    IMAGE_REL_SHM_PCRELPT,
> >>> +    IMAGE_REL_SHM_REFLO,
> >>> +    IMAGE_REL_SHM_REFHALF,
> >>> +    IMAGE_REL_SHM_RELLO,
> >>> +    IMAGE_REL_SHM_RELHALF,
> >>> +    IMAGE_REL_SHM_PAIR,
> >>> +    IMAGE_REL_SHM_NOMODE,
> >>> +};
> >>> +
> >>> +enum ppc_coff_reloc_type {
> >>> +    IMAGE_REL_PPC_ABSOLUTE,
> >>> +    IMAGE_REL_PPC_ADDR64,
> >>> +    IMAGE_REL_PPC_ADDR32,
> >>> +    IMAGE_REL_PPC_ADDR24,
> >>> +    IMAGE_REL_PPC_ADDR16,
> >>> +    IMAGE_REL_PPC_ADDR14,
> >>> +    IMAGE_REL_PPC_REL24,
> >>> +    IMAGE_REL_PPC_REL14,
> >>> +    IMAGE_REL_PPC_ADDR32N,
> >>> +    IMAGE_REL_PPC_SECREL,
> >>> +    IMAGE_REL_PPC_SECTION,
> >>> +    IMAGE_REL_PPC_SECREL16,
> >>> +    IMAGE_REL_PPC_REFHI,
> >>> +    IMAGE_REL_PPC_REFLO,
> >>> +    IMAGE_REL_PPC_PAIR,
> >>> +    IMAGE_REL_PPC_SECRELLO,
> >>> +    IMAGE_REL_PPC_GPREL,
> >>> +    IMAGE_REL_PPC_TOKEN,
> >>> +};
> >>> +
> >>> +enum x86_coff_reloc_type {
> >>> +    IMAGE_REL_I386_ABSOLUTE,
> >>> +    IMAGE_REL_I386_DIR16,
> >>> +    IMAGE_REL_I386_REL16,
> >>> +    IMAGE_REL_I386_DIR32,
> >>> +    IMAGE_REL_I386_DIR32NB,
> >>> +    IMAGE_REL_I386_SEG12,
> >>> +    IMAGE_REL_I386_SECTION,
> >>> +    IMAGE_REL_I386_SECREL,
> >>> +    IMAGE_REL_I386_TOKEN,
> >>> +    IMAGE_REL_I386_SECREL7,
> >>> +    IMAGE_REL_I386_REL32,
> >>> +};
> >>> +
> >>> +enum ia64_coff_reloc_type {
> >>> +    IMAGE_REL_IA64_ABSOLUTE,
> >>> +    IMAGE_REL_IA64_IMM14,
> >>> +    IMAGE_REL_IA64_IMM22,
> >>> +    IMAGE_REL_IA64_IMM64,
> >>> +    IMAGE_REL_IA64_DIR32,
> >>> +    IMAGE_REL_IA64_DIR64,
> >>> +    IMAGE_REL_IA64_PCREL21B,
> >>> +    IMAGE_REL_IA64_PCREL21M,
> >>> +    IMAGE_REL_IA64_PCREL21F,
> >>> +    IMAGE_REL_IA64_GPREL22,
> >>> +    IMAGE_REL_IA64_LTOFF22,
> >>> +    IMAGE_REL_IA64_SECTION,
> >>> +    IMAGE_REL_IA64_SECREL22,
> >>> +    IMAGE_REL_IA64_SECREL64I,
> >>> +    IMAGE_REL_IA64_SECREL32,
> >>> +    IMAGE_REL_IA64_DIR32NB,
> >>> +    IMAGE_REL_IA64_SREL14,
> >>> +    IMAGE_REL_IA64_SREL22,
> >>> +    IMAGE_REL_IA64_SREL32,
> >>> +    IMAGE_REL_IA64_UREL32,
> >>> +    IMAGE_REL_IA64_PCREL60X,
> >>> +    IMAGE_REL_IA64_PCREL60B,
> >>> +    IMAGE_REL_IA64_PCREL60F,
> >>> +    IMAGE_REL_IA64_PCREL60I,
> >>> +    IMAGE_REL_IA64_PCREL60M,
> >>> +    IMAGE_REL_IA64_IMMGPREL6,
> >>> +    IMAGE_REL_IA64_TOKEN,
> >>> +    IMAGE_REL_IA64_GPREL32,
> >>> +    IMAGE_REL_IA64_ADDEND,
> >>> +};
> >>
> >> All sorts of relocation types, but none for RISC-V? Are we going to need
> >> any of this?
> >>
> >>> +struct coff_reloc {
> >>> +    uint32_t virtual_address;
> >>> +    uint32_t symbol_table_index;
> >>> +
> >>> +    union {
> >>> +        enum x64_coff_reloc_type  x64_type;
> >>> +        enum arm_coff_reloc_type  arm_type;
> >>> +        enum sh_coff_reloc_type   sh_type;
> >>> +        enum ppc_coff_reloc_type  ppc_type;
> >>> +        enum x86_coff_reloc_type  x86_type;
> >>> +        enum ia64_coff_reloc_type ia64_type;
> >>> +        uint16_t                  data;
> >>> +    };
> >>> +};
> >>> +
> >>> +/*
> >>> + * Definitions for the contents of the certs data block
> >>> + */
> >>> +#define WIN_CERT_TYPE_PKCS_SIGNED_DATA 0x0002
> >>> +#define WIN_CERT_TYPE_EFI_OKCS115      0x0EF0
> >>> +#define WIN_CERT_TYPE_EFI_GUID         0x0EF1
> >>> +
> >>> +#define WIN_CERT_REVISION_1_0 0x0100
> >>> +#define WIN_CERT_REVISION_2_0 0x0200
> >>> +
> >>> +struct win_certificate {
> >>> +    uint32_t length;
> >>> +    uint16_t revision;
> >>> +    uint16_t cert_type;
> >>> +};
> >>
> >> Or any of this?
> >>
> > Regarding pe.h file content, we wanted to keep it as generic as
> > possible (structures definition according to PE format which can be
> > used for multiple architectures). Specifically for RISC-V as you
> > noticed, we are not using lots of structures (data directories,
> > relocation structures, certificates, etc.). Therefore, we can reduce
> > it to only those used atm, but in that case we won't have a generic PE
> > header definition anymore. Regarding structures which are already
> > defined in common/efi/pe.c, meaning that with our change we have two
> > versions of same structures, we can remove those, but in that case it
> > could be confusing for someone who is trying to map fields from pe.h
> > to actual image header in assembly code. Summary I would keep this
> > header with its original content, but if you think that it contains
> > too much overhead we can reduce it to relevant structures only.
>
> Actually I not only don't mind this header, but would consider it
> superior to the present state of things. Just that then imo it would
> want introducing in a separate commit, with suitable description /
> justification. That could (should) then be followed by a patch using
> this header's struct-s / definitions in pre-existing code, purging
> any duplication from there.
>
So we should have one commit for pe.h only, a subsequent commit where
x86 implementation is modified to use structures from pe.h and a third
commit where we add EFI stub for RISC-V?
And we can submit the first two commits separately from the RISC-V EFI
stub for which we'll wait on @Oleksii opinion on whether EFI
application format is needed upstream?
Just checking if my understanding is correct.

BR,
Milan



 


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