#ifndef UTSM_LINUX_LOADER_H #define UTSM_LINUX_LOADER_H #include /* ===== Linux boot protocol structures (Documentation/x86/boot.rst) ===== */ /* bzImage setup_header — lives at offset 0x1f1 inside bzImage and boot_params. * Only the fields we actually use are listed; gaps are reserved/padding. */ struct linux_setup_header { u8 setup_sects; /* 0x1f1: number of setup sectors */ u16 root_flags; /* 0x1f2 */ u32 syssize; /* 0x1f4: protected-mode code size / 16 */ u16 ram_size; /* 0x1f8 */ u16 vid_mode; /* 0x1fa */ u16 boot_flag; /* 0x1fe: 0xAA55 */ u16 jump; /* 0x200: jump insn */ u32 header; /* 0x202: "HdrS" magic */ u16 version; /* 0x206: boot protocol version */ u32 realmode_swtch; /* 0x208 */ u16 start_sys_seg; /* 0x20c */ u16 kernel_version; /* 0x20e: offset to version string */ u8 type_of_loader; /* 0x210 */ u8 loadflags; /* 0x211 */ u16 setup_move_size; /* 0x212 */ u32 code32_start; /* 0x214: 32-bit entry (also 64-bit entry base) */ u32 ramdisk_image; /* 0x218 */ u32 ramdisk_size; /* 0x21c */ u32 bootsect_kludge; /* 0x220 */ u16 heap_end_ptr; /* 0x224 */ u8 ext_loader_ver; /* 0x226 */ u8 ext_loader_type; /* 0x227 */ u32 cmd_line_ptr; /* 0x228: command line physical address */ u32 init_size; /* 0x22c: total init memory needed */ u32 acpi_rsdp_addr; /* 0x230 */ u8 _pad0[4]; /* 0x234: relocatable_kernel + min_alignment */ u16 xloadflags; /* 0x236: bit0=XLF_KERNEL_64 */ u32 cmdline_size; /* 0x238 */ u32 _pad1; /* 0x23c */ u64 setup_data; /* 0x240: linked list of setup_data */ u64 pref_address; /* 0x248 → wait, this is payload_offset */ /* NOTE: The real layout continues with payload_offset at 0x248. * However, pref_address is at 0x258 and init_size at 0x260. * The struct above is intentionally simplified — we read fields * by offset rather than relying on this struct for the full layout. */ } __attribute__((packed)); /* boot_params is 4096 bytes. The setup_header is at offset 0x1f1. */ #define BOOT_PARAMS_SIZE 4096 #define SETUP_HEADER_OFFSET 0x1f1 /* Key field offsets within bzImage / boot_params */ #define BZ_BOOT_FLAG_OFF 0x1fe #define BZ_HEADER_MAGIC 0x53726448 /* "HdrS" */ #define BZ_HEADER_OFF 0x202 #define BZ_VERSION_OFF 0x206 #define BZ_TYPE_OF_LOADER_OFF 0x210 #define BZ_LOADFLAGS_OFF 0x211 #define BZ_CODE32_START_OFF 0x214 #define BZ_RAMDISK_IMAGE_OFF 0x218 #define BZ_RAMDISK_SIZE_OFF 0x21c #define BZ_CMD_LINE_PTR_OFF 0x228 #define BZ_INIT_SIZE_OFF 0x22c /* wait — actually init_size is at 0x260 */ #define BZ_XLOADFLAGS_OFF 0x236 #define BZ_CMDLINE_SIZE_OFF 0x238 #define BZ_PAYLOAD_OFFSET_OFF 0x248 #define BZ_PAYLOAD_LENGTH_OFF 0x24c #define BZ_PREF_ADDRESS_OFF 0x258 #define BZ_INIT_SIZE_ACTUAL_OFF 0x260 /* xloadflags bits */ #define XLF_KERNEL_64 0x0001 #define XLF_CAN_BE_LOADED_ABOVE 0x0002 #define XLF_EFI_HANDOVER 0x0010 #define XLF_EFI_KEXEC 0x0020 /* loadflags bits */ #define LOADFLAG_LOADED_HIGH 0x01 #define LOADFLAG_KEEP_ROOT 0x02 #define LOADFLAG_CAN_USE_HEAP 0x80 /* e820 entry types */ #define E820_TYPE_RAM 1 #define E820_TYPE_RESERVED 2 #define E820_TYPE_ACPI 3 #define E820_TYPE_NVS 4 #define E820_TYPE_UNUSABLE 5 #define E820_TYPE_PMEM 7 /* e820_table entry in boot_params at offset 0x2e0 (actually 0x2d0 in older, * 0x2e0 in newer). We use 0x2e0 and the e820_entries count at 0x1e8. * Each entry is 20 bytes: u64 addr, u64 size, u32 type. */ #define E820_ENTRIES_OFFSET 0x1e8 #define E820_TABLE_OFFSET 0x2e0 #define E820_MAX_ENTRIES 128 #define E820_ENTRY_SIZE 20 /* ===== Guest memory layout (GPA) ===== * Based on utsm-linux-dual-kernel-architecture.md. * 0x00000000-0x003FFFFF : UTSM reserved (denied to Linux) * 0x00400000-0x004FFFFF : boot_params / cmdline / GDT / page tables / stack * 0x01000000-0x02FFFFFF : Linux kernel image * 0x03000000-0x03FFFFFF : Linux initrd * 0x04000000-0x040FFFFF : IPC shared memory (1MB, both kernels RW) * 0x05000000-MAX : Linux general RAM */ #define LINUX_GUEST_KERNEL_GPA 0x01000000ULL /* 16 MB, 2MB-aligned */ #define LINUX_GUEST_BOOTPARAMS_GPA 0x00400000ULL /* 4 MB */ #define LINUX_GUEST_CMDLINE_GPA 0x00500000ULL /* 5 MB */ #define LINUX_GUEST_INITRD_GPA 0x03000000ULL /* 48 MB (within kernel+initrd region) */ #define LINUX_GUEST_STACK_GPA 0x00800000ULL /* 8 MB (stack grows down) */ #define LINUX_GUEST_GDT_GPA 0x00600000ULL /* 6 MB (guest GDT) */ #define LINUX_GUEST_PGT_GPA 0x00700000ULL /* 7 MB (guest page tables) */ #define LINUX_GUEST_CMDLINE_MAX 4096 /* IPC shared memory GPA (must match CODE/utsm-ipc/ipc_proto.h) */ #define LINUX_GUEST_IPC_SHM_GPA 0x04000000ULL /* 64 MB */ #define LINUX_GUEST_IPC_SHM_SIZE (1024 * 1024) /* 1MB */ /* General RAM starts after IPC region */ #define LINUX_GUEST_RAM_GPA 0x05000000ULL /* 80 MB */ /* ===== virtio-mmio device GPA layout ===== * virtio-mmio 设备放在 GPA 高位 MMIO 区（guest RAM 之上，不占用 e820 RAM）。 * guest 通过 cmdline 参数 virtio_mmio.device= 发现这些设备。 * 每个设备占 0x200 字节寄存器空间（virtio-mmio 规范要求 4KB 对齐）。 * * 这些 GPA 在 EPT 中【故意不映射】，访问时触发 EPT violation， * 由 vmexit handler 路由到 virtio_mmio 后端模拟寄存器读写。 * * GPA 选择 0xF4000000 起始（接近 4GB，远离 guest RAM 0x05000000-0x09000000）。 */ #define VIRTIO_MMIO_GPA_BASE 0xF4000000ULL #define VIRTIO_MMIO_GPA_STRIDE 0x1000ULL /* 每个设备 4KB */ #define VIRTIO_MMIO_BLK_GPA (VIRTIO_MMIO_GPA_BASE + 0 * VIRTIO_MMIO_GPA_STRIDE) /* 0xF4000000 */ #define VIRTIO_MMIO_NET_GPA (VIRTIO_MMIO_GPA_BASE + 1 * VIRTIO_MMIO_GPA_STRIDE) /* 0xF4001000 */ /* 判断 GPA 是否落在 virtio-mmio 设备区（含两端） */ #define VIRTIO_MMIO_GPA_END (VIRTIO_MMIO_GPA_BASE + 2 * VIRTIO_MMIO_GPA_STRIDE) #define IS_VIRTIO_MMIO_GPA(gpa) ((gpa) >= VIRTIO_MMIO_GPA_BASE && (gpa) < VIRTIO_MMIO_GPA_END) /* ===== Linux loader API ===== */ /* Loaded Linux guest state */ struct linux_guest_info { u64 kernel_gpa; /* GPA where kernel was loaded */ u64 kernel_entry; /* 64-bit entry point GPA */ u64 kernel_size; /* Size of loaded kernel image */ u64 bootparams_gpa; /* GPA of boot_params */ u64 cmdline_gpa; /* GPA of command line */ u64 cmdline_size; /* Command line length (with NUL) */ u64 initrd_gpa; /* GPA of initrd (0 = none) */ u64 initrd_size; /* Size of initrd */ u64 pgt_gpa; /* GPA of guest page tables */ u64 gdt_gpa; /* GPA of guest GDT */ int loaded; /* 1 = successfully loaded */ }; /* Find the Linux bzImage boot module among Limine modules. * Returns pointer to the module data, or NULL if not found. * Sets *size_out to the module size. */ void *linux_find_bzimage_module(u64 *size_out); /* Parse bzImage header and extract key parameters. * Returns 0 on success, negative on error. */ int linux_parse_bzimage(const void *bzimage, u64 size, u64 *payload_offset_out, u64 *payload_length_out, u64 *init_size_out, u64 *entry_offset_out); /* Initialize the Linux guest: parse bzImage, allocate guest memory, * set up boot_params, page tables, GDT, and EPT mappings. * Returns 0 on success, negative on error. */ int linux_loader_init(void); /* Get the loaded Linux guest info (NULL if not loaded). */ const struct linux_guest_info *linux_get_guest_info(void); /* Configure VMCS for Linux guest and perform vmlaunch. * Must be called after vmm_init() + linux_loader_init(). * Returns 0 on successful guest termination, negative on error. */ int linux_launch(void); /* Default Linux command line (can be overridden). * nohlt: prevent kernel idle loop from using HLT — only the exec daemon's * explicit ioctl(PARK) HLT should trigger VM-Exit park, so that * linux_launch() returns only after the daemon is ready. * noapic/nolapic/nosmp: UTSM VMM 只模拟 legacy PIC(8259) + PIT(8254)， * 不提供 LAPIC/IOAPIC；guest 走 XT-PIC 模式，IRQ vector = 0x30+irq。 * virtio_mmio.device=: 向 guest 声明 virtio-mmio 设备（blk@0xF4000000 IRQ5, * net@0xF4001000 IRQ6），需 CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES=y。 */ #define LINUX_DEFAULT_CMDLINE \ "console=ttyS0,115200 earlyprintk=serial nokaslr " \ "no_timer_check loglevel=7 nohlt idle=poll " \ "noapic nolapic nosmp " \ "virtio_mmio.device=4K@0xF4000000:5 " \ "virtio_mmio.device=4K@0xF4001000:6" #endif