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const std = @import("std");
const elf = std.elf;
const Allocator = std.mem.Allocator;
const root = @import("root");
const Block = root.Block;
pub fn create_elf(allocator: Allocator, block: Block) ![]u8 {
_ = block;
const base_addr = 0x10000000;
const elf_header: elf.Elf64_Ehdr = .{
.e_ident = elf.MAGIC.* ++ [_]u8{
elf.ELFCLASS64, // EI_CLASS
elf.ELFDATA2LSB, // EI_DATA
1, // EI_VERSION
@intFromEnum(elf.OSABI.NONE), // EI_OSABI
0, // EI_ABIVERSION
} ++ [1]u8{0} ** 7, // EI_PAD
.e_type = .EXEC,
.e_machine = elf.EM.RISCV,
.e_version = 1,
.e_entry = base_addr + @sizeOf(elf.Elf64_Ehdr) + @sizeOf(elf.Elf64_Phdr), // we place the code directly after the headers
.e_phoff = @sizeOf(elf.Elf64_Ehdr), // we place the program header(s) directly after the elf header
.e_shoff = 0,
.e_flags = 0, // ?
.e_ehsize = @sizeOf(elf.Elf64_Ehdr),
.e_phentsize = @sizeOf(elf.Elf64_Phdr),
.e_phnum = 1,
.e_shentsize = @sizeOf(elf.Elf64_Shdr),
.e_shnum = 0,
.e_shstrndx = 0,
};
const program_header: elf.Elf64_Phdr = .{
.p_type = elf.PT_LOAD,
.p_flags = elf.PF_R | elf.PF_X,
.p_offset = 0,
.p_vaddr = base_addr,
.p_paddr = base_addr,
.p_filesz = @sizeOf(elf.Elf64_Ehdr) + @sizeOf(elf.Elf64_Phdr) + 40,
.p_memsz = @sizeOf(elf.Elf64_Ehdr) + @sizeOf(elf.Elf64_Phdr) + 40,
.p_align = 0x1000,
};
var output_buffer: std.ArrayList(u8) = .init(allocator);
errdefer output_buffer.deinit();
const output = output_buffer.writer();
try output.writeAll(std.mem.asBytes(&elf_header));
try output.writeAll(std.mem.asBytes(&program_header));
for (0..10) |_| try output.writeAll(&std.mem.toBytes(@as(u32, 0x13)));
return output_buffer.toOwnedSlice();
}
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