include: create the basics of a libc

Create the most basic files for a POSIX-conformant standard C library
implementation. These basic files should be enough to get the bootloader
and kernel off the ground and not much else. Additional testing should
be done on these files.

Signed-off-by: Danny Holman <dholman@gymli.org>

8 files changed, 985 insertions, 0 deletions

diff --git a/include/TODO b/include/TODO
new file mode 100644
index 0000000..a845564
--- /dev/null
+++ b/include/TODO
@@ -0,0 +1,4 @@
+* elf.h has lots of missing definitions
+* stdint.h and stddef.h are missing a 32 bit zarch check
+* LOTS of testing needs to happen with various architectures
+* everything is missing the "extern C" bit that allows for C++
diff --git a/include/bootabi/bootparam.h b/include/bootabi/bootparam.h
new file mode 100644
index 0000000..0ec28d9
--- /dev/null
+++ b/include/bootabi/bootparam.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2025 Danny Holman <dholman@gymli.org>
+ *
+ * This file is part of BoxOS, a free and open-source Unix-like operating
+ * system.
+ *
+ * BoxOS is free software; you can redistribute it and/or modify under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * BoxOS is distributed in the hope it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * BoxOS; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef SYS_BOOTPARAM_H
+#define SYS_BOOTPARAM_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+#define FIRMWARE_UEFI           1
+#define FIRMWARE_OSBI           2
+
+#define MAX_CMDLINE_SIZE        1024
+
+#define BOOTPARAM_MAGIC         0x424F4F54 // "BOOT"
+
+enum mem_type {
+        MEM_USABLE,
+        MEM_IO,
+        MEM_ACPI,
+        MEM_ACPI_RECLAIM,
+        MEM_PERSIST,
+        MEM_FIRMWARE,
+};
+
+typedef struct mmap_entry {
+        uint8_t mem_type;
+        uint64_t num_pages;
+        uintptr_t start;
+        struct mmap_entry *next;
+} mmap_entry_t;
+
+typedef struct bootparam {
+        uint32_t magic;
+        uint32_t firmware_id;
+        void *stack_ptr;
+        void *heap_ptr;
+        void *firmware_params;
+        uint32_t num_mmap_entries;
+        mmap_entry_t *mmap;
+        char cmdline[MAX_CMDLINE_SIZE];
+} bootparam_t;
+
+#endif
diff --git a/include/bootabi/efi.h b/include/bootabi/efi.h
new file mode 100644
index 0000000..9db688d
--- /dev/null
+++ b/include/bootabi/efi.h
@@ -0,0 +1,454 @@
+/*
+ * Copyright (C) 2025 Danny Holman <dholman@gymli.org>
+ *
+ * This file is part of BoxOS, a free and open-source Unix-like operating
+ * system.
+ *
+ * BoxOS is free software; you can redistribute it and/or modify under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * BoxOS is distributed in the hope it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * BoxOS; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef BOOTABI_EFI_H
+#define BOOTABI_EFI_H
+
+#include <stdint.h>
+#include <uchar.h>
+#include <limits.h>
+
+#define EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL    0x00000001
+#define EFI_OPEN_PROTOCOL_BY_GET_PROTOCOL       0x00000002
+#define EFI_OPEN_PROTOCOL_TEST_PROTOCOL         0x00000004
+#define EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER   0x00000008
+#define EFI_OPEN_PROTOCOL_BY_DRIVER             0x00000010
+#define EFI_OPEN_PROTOCOL_EXCLUSIVE             0x00000020
+
+#define EFI_TRUE                                1
+#define EFI_FALSE                               0
+
+typedef struct efi_guid {
+        uint32_t data1;
+        uint16_t data2;
+        uint16_t data3;
+        uint8_t data4[8];
+} efi_guid_t;
+
+static const efi_guid_t EFI_FILE_INFO_ID = {0x09576E92, 0x6D3F, 0x11D2, {0x8E, 0x39, 0x00, 0xA0, 0xC9, 0x69, 0x72, 0x3B}};
+static const efi_guid_t EFI_LOAD_FILE_PROTOCOL_ID = {0x5B1B31A1, 0x9562, 0x11D2, {0x8E, 0x3F, 0x00, 0xA0, 0xC9, 0x69, 0x72, 0x3B}};
+static const efi_guid_t EFI_DEVICE_PATH_PROTOCOL_ID = {0x09576E91, 0x6D3F, 0x11D2, {0x8E, 0x39, 0x00, 0xA0, 0xC9, 0x69, 0x72, 0x3B}};
+static const efi_guid_t EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_ID = {0x0964E5B22, 0x6459, 0x11D2, {0x8E, 0x39, 0x00, 0xA0, 0xC9, 0x69, 0x72, 0x3B}};
+static const efi_guid_t EFI_LOADED_IMAGE_PROTOCOL_ID = {0x5B1B31A1, 0x9562, 0x11d2, {0x8E,0x3F,0x00,0xA0,0xC9,0x69,0x72,0x3B}};
+static const efi_guid_t EFI_GRAPHICS_OUTPUT_PROTOCOL_ID = {0x9042A9DE, 0x23DC, 0x4A38, {0x96, 0xFB, 0x7A, 0xDE, 0xD0, 0x80, 0x51, 0x6A}};
+
+typedef struct efi_time {
+        uint16_t year;
+        uint8_t month;
+        uint8_t day;
+        uint8_t hour;
+        uint8_t minute;
+        uint8_t second;
+        uint8_t PAD0;
+        uint32_t nsecond;
+        uint16_t time_zone;
+        uint8_t dst;
+        uint8_t PAD1;
+} efi_time_t;
+
+typedef struct efi_time_cap {
+        uint32_t resolution;
+        uint32_t accuracy;
+        uint8_t set_to_zero;
+} efi_time_cap_t;
+
+enum efi_alloc_type {
+        AllocateAnyPages,
+        AllocateMaxAddress,
+        AllocateAddress,
+        MaxAllocateType,
+};
+
+enum efi_memory_type {
+        ReservedMemory,
+        LoaderCode,
+        LoaderData,
+        BootSrvCode,
+        BootSrvData,
+        RuntimeSrvCode,
+        RuntimeSrvData,
+        ConventionalMemory,
+        UnusableMemory,
+        ACPIReclaimMemory,
+        ACPIMemoryNVS,
+        MemoryMappedIO,
+        MemoryMappedIOPortSpace,
+        PalCode,
+        PersistentMemory,
+        UnacceptedMemory,
+        MaxMemory,
+};
+
+#define EFIERR(X) ((uint64_t)(0x8000000000000000 | (X)))
+
+enum efi_status {
+        EFI_SUCCESS,
+        EFI_LOAD_ERROR,
+        EFI_INVALID_PARAMETER,
+        EFI_UNSUPPORTED,
+        EFI_BAD_BUFFER_SIZE,
+        EFI_BUFFER_TOO_SMALL,
+        EFI_NOT_READY,
+        EFI_DEVICE_ERROR,
+        EFI_WRITE_PROTECTED,
+        EFI_OUT_OF_RESOURCES,
+        EFI_VOLUME_CORRUPTED,
+        EFI_VOLUME_FULL,
+        EFI_NO_MEDIA,
+        EFI_MEDIA_CHANGED,
+        EFI_NOT_FOUND,
+        EFI_ACCESS_DENIED,
+        EFI_NO_RESPONSE,
+        EFI_NO_MAPPING,
+        EFI_TIMEOUT,
+        EFI_NOT_STARTED,
+        EFI_ALREADY_STARTED,
+        EFI_ABORTED,
+        EFI_ICMP_ERROR,
+        EFI_TFTP_ERROR,
+        EFI_PROTOCOL_ERROR,
+        EFI_INCOMPATIBLE_VERSION,
+        EFI_SECURITY_VIOLATION,
+        EFI_CRC_ERROR,
+        EFI_END_OF_MEDIA,
+        EFI_END_OF_FILE,
+        EFI_INVALID_LANGUAGE,
+        EFI_COMPROMISED_DATA,
+        EFI_IP_ADDRESS_CONFLICT,
+        EFI_HTTP_ERROR,
+};
+
+static char* efi_status_str[] = {
+        "Success",
+        "Load error",
+        "Invalid parameter",
+        "Unsupported operation",
+        "Bad buffer size",
+        "Buffer too small",
+        "Not ready",
+        "Device error",
+        "Write protected",
+        "Out of resources",
+        "Volume corrupted",
+        "Volume full",
+        "No media",
+        "Media changed",
+        "Not found",
+        "Access denied",
+        "No response",
+        "No mapping",
+        "Operation timeout",
+        "Operation not started",
+        "Operation already started",
+        "Operation aborted",
+        "ICMP error",
+        "TFTP error",
+        "Protocol error",
+        "Incompatible version",
+        "Security violation",
+        "Checksum error",
+        "End of media",
+        "End of file",
+        "Invalid language",
+        "Compressed data",
+        "IP conflict",
+        "HTTP error"
+};
+
+enum efi_reset_type {
+        EFI_RESET_COLD,
+        EFI_RESET_WARM,
+        EFI_RESET_SHUTDOWN,
+        EFI_RESET_PFORM_SPECIFIC,
+};
+
+typedef struct efi_memory_descriptor {
+        uint32_t type;
+        uintptr_t physical_start;
+        uintptr_t virtual_start;
+        uint64_t num_pages;
+        uint64_t attribute;
+} efi_memory_descriptor_t;
+
+typedef struct efi_input_key {
+        uint16_t scancode;
+        uint16_t unicode;
+} efi_input_key_t;
+
+typedef struct efi_text_input {
+        uint64_t (*read_key_stroke)(struct efi_text_input *this, efi_input_key_t *key);
+        void *wait_for_key;
+} efi_text_input_t;
+
+typedef struct efi_text_output_mode {
+        int32_t max_mode;
+        int32_t mode;
+        int32_t attribute;
+        int32_t cursor_x;
+        int32_t cursor_y;
+        uint8_t cursor_enable;
+} efi_text_output_mode_t;
+
+typedef struct efi_text_output {
+        uint64_t (*reset)(struct efi_text_output*, uint8_t);
+        uint64_t (*output_str)(struct efi_text_output*, char16_t*);
+        uint64_t (*test_string)(struct efi_text_output*, char16_t*);
+        uint64_t (*query_mode)(struct efi_text_output*, uint64_t);
+        uint64_t (*set_mode)(struct efi_text_output*, uint64_t);
+        uint64_t (*set_attribute)(struct efi_text_output*, uint64_t);
+        uint64_t (*clear_screen)(struct efi_text_output*);
+        uint64_t (*set_cursor)(struct efi_text_output*, uint64_t, uint64_t);
+        uint64_t (*enable_cursor)(struct efi_text_output*, uint8_t);
+        efi_text_output_mode_t *mode;
+} efi_text_output_t;
+
+typedef struct efi_device_path {
+        uint8_t type;
+        uint8_t sub_type;
+        uint8_t length[2];
+} efi_device_path_t;
+
+typedef struct efi_protocol_entry {
+        void *agent_handle;
+        void *controller_handle;
+        uint32_t attributes;
+        uint32_t count;
+} efi_protocol_entry_t;
+
+typedef struct efi_cap_hdr {
+        efi_guid_t cap_guid;
+        uint32_t header_sz;
+        uint32_t flags;
+        uint32_t cap_sz;
+} efi_cap_hdr_t;
+
+#define EFI_FILE_MODE_READ      (1 << 0)
+#define EFI_FILE_MODE_WRITE     (2 << 0)
+#define EFI_FILE_MODE_CREATE    (8 << 60)
+
+#define EFI_FILE_READ_ONLY      (1 << 0)
+#define EFI_FILE_HIDDEN         (2 << 0)
+#define EFI_FILE_SYSTEM         (4 << 0)
+#define EFI_FILE_RESERVED       (8 << 0)
+#define EFI_FILE_DIRECTORY      (1 << 4)
+#define EFI_FILE_ARCHIVE        (2 << 4)
+#define EFI_FILE_VALID_ATTR     (55 << 0)
+
+#define FILENAME_MAX            255
+
+typedef struct efi_file_io_token {
+        void *event;
+        uint64_t status;
+        uint64_t bufsz;
+        void *buffer;
+} efi_file_io_token_t;
+
+typedef struct efi_file_protocol {
+        uint64_t revision;
+        uint64_t (*open)(struct efi_file_protocol*, struct efi_file_protocol**, char16_t*, uint64_t, uint64_t);
+        uint64_t (*close)(struct efi_file_protocol*);
+        uint64_t (*deletef)(struct efi_file_protocol*);
+        uint64_t (*read)(struct efi_file_protocol*, uint64_t*, void*);
+        uint64_t (*write)(struct efi_file_protocol*, uint64_t*, void*);
+        uint64_t (*get_position)(struct efi_file_protocol*, uint64_t*);
+        uint64_t (*set_position)(struct efi_file_protocol*, uint64_t);
+        uint64_t (*get_info)(struct efi_file_protocol*, efi_guid_t*, uint64_t*, void*);
+        uint64_t (*set_info)(struct efi_file_protocol*, efi_guid_t*, uint64_t, void*);
+        uint64_t (*flush)(struct efi_file_protocol*);
+        uint64_t (*open_ex)(struct efi_file_protocol*, struct efi_file_protocol**, char16_t*, uint64_t, uint64_t, efi_file_io_token_t*);
+        uint64_t (*read_ex)(struct efi_file_protocol*, efi_file_io_token_t*);
+        uint64_t (*write_ex)(struct efi_file_protocol*, efi_file_io_token_t*);
+        uint64_t (*flush_ex)(struct efi_file_protocol*, efi_file_io_token_t*);
+} efi_file_protocol_t;
+
+typedef struct efi_file_info {
+        uint64_t size;
+        uint64_t file_size;
+        uint64_t phys_size;
+        efi_time_t ctime;
+        efi_time_t atime;
+        efi_time_t mtime;
+        uint64_t attribute;
+        uint16_t filename[FILENAME_MAX];
+} efi_file_info_t;
+
+typedef struct efi_simple_file_system_protocol {
+        uint32_t revision;
+        uint64_t (*open_volume)(void*, efi_file_protocol_t**);
+} efi_simple_file_system_protocol_t;
+
+typedef struct efi_table_hdr {
+        uint64_t signature;
+        uint32_t revision;
+        uint32_t header_sz;
+        uint32_t crc32;
+        uint32_t RESERVED;
+} efi_table_hdr_t;
+
+typedef struct efi_runtime {
+        efi_table_hdr_t header;
+        uint64_t (*gettime)(efi_time_t*, efi_time_cap_t*);
+        uint64_t (*settime)(efi_time_t*);
+        uint64_t (*getwaketime)(uint8_t*, uint8_t*, efi_time_t*);
+        uint64_t (*setwaketime)(uint8_t, efi_time_t*);
+        uint64_t (*setvmap)(uint64_t, uint64_t, uint32_t, efi_memory_descriptor_t*);
+        uint64_t (*convert_pointer)(uint64_t, void**);
+        uint64_t (*getvar)(uint16_t*, efi_guid_t*, uint32_t*, uint64_t*, void*);
+        uint64_t (*getnextvar)(uint64_t*, uint16_t*, efi_guid_t*);
+        uint64_t (*setvar)(uint16_t*, efi_guid_t*, uint32_t, uint64_t, void*);
+        uint64_t (*gethimon)(uint64_t*);
+        uint64_t (*reset_system)(int, uint64_t, uint64_t, uint16_t*);
+        uint64_t (*update_cap)(efi_cap_hdr_t**, uint64_t, uintptr_t);
+        uint64_t (*query_cap)(efi_cap_hdr_t**, uint64_t, uint64_t*, int*);
+        uint64_t (*query_var)(uint32_t, uint64_t*, uint64_t*, uint64_t*);
+} efi_runtime_t;
+
+typedef struct efi_boot {
+        efi_table_hdr_t header;
+        uint64_t (*raise_tpl)(uint64_t);
+        uint64_t (*restore_tpl)(uint64_t);
+        uint64_t (*allocate_pages)(int, int, uint64_t, uintptr_t*);
+        uint64_t (*free_pages)(uintptr_t, uint64_t);
+        uint64_t (*get_memory_map)(uint64_t*, efi_memory_descriptor_t*, uint64_t*, uint64_t*, uint32_t*);
+        uint64_t (*allocate_pool)(int, uint64_t, void**);
+        uint64_t (*free_pool)(void*);
+        uint64_t (*create_event)(uint32_t, uint64_t, void*, void*, void*);
+        uint64_t (*set_timer)(void*, int, uint64_t);
+        uint64_t (*wait_event)(uint64_t, void*, uint64_t*);
+        uint64_t (*signal_event)(void*);
+        uint64_t (*close_event)(void*);
+        uint64_t (*check_event)(void*);
+        void *install_protocol_interface;
+        void *reinstall_protocol_interface;
+        void *uninstall_protocol_interface;
+        uint64_t (*handle_protocol)(void**, const efi_guid_t*, void**);
+        uint64_t (*pc_handle_protocol)(void**, const efi_guid_t*, void**);
+        uint64_t (*register_protocol)(efi_guid_t*, void*, void**);
+        uint64_t (*locate_handle)(int, efi_guid_t*, void*, uint64_t*, void**);
+        uint64_t (*locate_device_path)(efi_guid_t*, efi_device_path_t**, void**);
+        uint64_t (*install_cfg_table)(efi_guid_t*, void*);
+        uint64_t (*load_image)(uint8_t, void*, efi_device_path_t*, void*, uint64_t, void**);
+        uint64_t (*start_image)(void*, uint64_t*, uint16_t**);
+        uint64_t (*exit)(void*, uint64_t, uint64_t, uint16_t*);
+        uint64_t (*unload_image)(void);
+        uint64_t (*exit_boot_services)(void*, uint64_t);
+        uint64_t (*gethimon)(uint64_t*);
+        uint64_t (*stall)(uint64_t);
+        uint64_t (*setwatchdog)(uint64_t, uint64_t, uint64_t, uint16_t*);
+        uint64_t (*connect_cont)(void*, void**, efi_device_path_t*, uint8_t);
+        uint64_t (*disconnect_cont)(void*, void*, void*);
+        uint64_t (*open_protocol)(void*, efi_guid_t*, void**, void*, void*, uint32_t);
+        uint64_t (*close_protocol)(void*, efi_guid_t*, void*, void*);
+        uint64_t (*open_protocol_info)(void*, efi_guid_t*, efi_protocol_entry_t**, uint64_t*);
+        uint64_t (*protocols_per_handle)(void*, efi_guid_t***, uint64_t*);
+        uint64_t (*locate_handle_buffer)(int, efi_guid_t*, void*, uint64_t*, void***);
+        uint64_t (*locate_protocol)(efi_guid_t*, void*, void**);
+        void *install_many_protocols;
+        void *uninstall_many_protocols;
+        uint64_t (*calc_crc32)(void*, uint64_t, uint32_t*);
+} efi_boot_t;
+
+typedef struct efi_system {
+        efi_table_hdr_t header;
+        uint16_t *firmware_vendor;
+        uint32_t firmware_revision;
+        void *console_in_handle;
+        efi_text_input_t *console_in;
+        void *console_out_handle;
+        efi_text_output_t *console_out;
+        void *console_err_handle;
+        efi_text_output_t *console_err;
+        efi_runtime_t *runtime;
+        efi_boot_t *bootsrv;
+        uint64_t num_entries;
+        void *config_table;
+} efi_system_t;
+
+typedef struct efi_load_file_protocol {
+        uint64_t (*load_file)(struct efi_load_file_protocol*, efi_device_path_t*, uint8_t, uint64_t, void*);
+} efi_load_file_protocol_t;
+
+typedef struct efi_loaded_image_protocol {
+        uint64_t revision;
+        void *parent_handle;
+        efi_system_t *system_table;
+        void *device_handle;
+        uint16_t *file_path;
+        void *RESERVED;
+        uint32_t options_size;
+        void *options;
+        void *image_base;
+        uint64_t image_size;
+        uint64_t image_code_type;
+        uint64_t image_data_type;
+} efi_loaded_image_protocol_t;
+
+typedef struct efi_pixel_bitmask {
+        uint32_t red;
+        uint32_t green;
+        uint32_t blue;
+        uint32_t alpha;
+} efi_pixel_bitmask_t;
+
+enum efi_gop_pixel_format {
+        RGBA8,
+        BGRA8,
+        BIT_MASK,
+        BIT_ONLY,
+        FORMAT_MAX,
+};
+
+typedef struct efi_gop_info {
+        uint32_t version;
+        uint32_t width;
+        uint32_t height;
+        enum efi_gop_pixel_format format;
+        efi_pixel_bitmask_t pixel_info;
+        uint32_t pixels_per_scaline;
+} efi_gop_info_t;
+
+typedef struct efi_gop_mode {
+        uint32_t max_mode;
+        uint32_t mode;
+        efi_gop_info_t *info;
+        uint64_t info_sz;
+        uintptr_t fb_base;
+        uint64_t fb_sz;
+} efi_gop_mode_t;
+
+typedef struct efi_gop {
+        uint64_t (*query_mode)();
+        uint64_t (*set_mode)();
+        uint64_t (*blt)();
+        efi_gop_mode_t *mode;
+} efi_gop_t;
+
+typedef struct efi_bootparam {
+        efi_system_t *st;
+        efi_memory_descriptor_t *mmap;
+        uint64_t mmap_size;
+        uint64_t mmap_key;
+        uint64_t mmap_dsize;
+        efi_gop_mode_t* gop_mode;
+} efi_bootparam_t;
+
+uint64_t efi_abi_wrapper(void *efi_func, ...);
+uint64_t sysv_abi_wrapper(void *sysv_func, ...);
+
+#endif
diff --git a/include/elf.h b/include/elf.h
new file mode 100644
index 0000000..6ffcf5d
--- /dev/null
+++ b/include/elf.h
@@ -0,0 +1,228 @@
+/*
+ * Copyright (C) 2025 Danny Holman <dholman@gymli.org>
+ *
+ * This file is part of BoxOS, a free and open-source Unix-like operating
+ * system.
+ *
+ * BoxOS is free software; you can redistribute it and/or modify under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * BoxOS is distributed in the hope it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * BoxOS; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef ELF_H
+#define ELF_H
+
+//#ifdef __cplusplus
+//extern "C" {
+//#endif
+
+#include <stdint.h>
+
+#define EI_NIDENT               (16)
+
+#define ELF_MAGIC               "\177ELF"
+
+#define EI_CLASS                4
+#define ELFCLASSNONE            0
+#define ELFCLASS32              1
+#define ELFCLASS64              2
+#define ELFCLASSNUM             3
+
+#define EI_DATA                 5
+#define ELFDATANONE             0
+#define ELFDATA2LSB             1
+#define ELFDATA2MSB             2
+#define ELFDATANUM              3
+
+#define ELFOSABI_SYSV           0
+#define ELFOSABI_HPUX           1
+#define ELFOSABI_NETBSD         2
+#define ELFOSABI_LINUX          3
+#define ELFOSABI_SOLARIS        6
+#define ELFOSABI_AIX            7
+#define ELFOSABI_IRIX           8
+#define ELFOSABI_FREEBSD        9
+#define ELFOSABI_OPENBSD        12
+#define ELFOSABI_ARM_AEABI      64
+#define ELFOSABI_ARM            97
+#define ELFOSABI_STANDALONE     255
+
+#define ET_NONE                 0
+#define ET_REL                  1
+#define ET_EXEC                 2
+#define ET_DYN                  3
+#define ET_CORE                 4
+#define ET_NUM                  5
+#define ET_LOOS                 0xFE00
+#define ET_HIOS                 0xFEFF
+#define ET_LOPROC               0xFF00
+#define ET_HIPROC               0xFFFF
+
+#define EM_NONE                 0
+#define EM_M32                  1
+#define EM_SPARC                2
+#define EM_386                  3
+#define EM_68K                  4
+#define EM_88K                  5
+#define EM_IAMCU                6
+#define EM_860                  7
+#define EM_MIPS                 8
+#define EM_S370                 9
+#define EM_MIPS_RS3_LE          10
+#define EM_PARISC               15
+#define EM_VPP500               17
+#define EM_SPARC32PLUS          18
+#define EM_960                  19
+#define EM_PPC                  20
+#define EM_PPC64                21
+#define EM_S390                 22
+#define EM_SPU                  23
+#define EM_V800                 36
+#define EM_FR20                 37
+#define EM_RH32                 38
+#define EM_RCE                  39
+#define EM_ARM                  40
+#define EM_FAKE_ALPHA           41
+#define EM_SH                   42
+#define EM_SPARCV9              43
+#define EM_TRICORE              44
+#define EM_ARC                  45
+#define EM_H8_300               46
+#define EM_H8_300H              47
+#define EM_H8S                  48
+#define EM_H8_500               49
+#define EM_IA_64                50
+#define EM_MIPS_X               51
+// TODO: the rest of these
+#define EM_X86_64               62
+#define EM_AARCH64              183
+#define EM_RISCV                243
+
+#define PT_NULL                 0
+#define PT_LOAD                 1
+#define PT_DYNAMIC              2
+#define PT_INTERP               3
+#define PT_NOTE                 4
+#define PT_SHLIB                5
+#define PT_PHDR                 6
+#define PT_TLS                  7
+#define PT_NUM                  8
+#define PT_LOOS                 0x60000000
+#define PT_GNU_EH_FRAME         0x6474e550
+#define PT_GNU_STACK            0x6474e551
+#define PT_GNU_RELRO            0x6474e552
+#define PT_GNU_PROPERTY         0x6474e553
+#define PT_GNU_SFRAME           0x6474e554
+
+#define R_X86_64_NONE           0
+#define R_X86_64_64             1
+#define R_X86_64_PC32           2
+#define R_X86_64_GOT32          3
+#define R_X86_64_PLT32          4
+#define R_X86_64_COPY           5
+#define R_X86_64_GLOB_DAT       6
+#define R_X86_64_JUMP_SLOT      7
+#define R_X86_64_RELATIVE       8
+#define R_X86_64_GOTPCREL       9
+#define R_X86_64_32             10
+#define R_X86_64_32S            11
+#define R_X86_64_16             12
+#define R_X86_64_PC16           13
+#define R_X86_64_8              14
+#define R_X86_64_PC8            15
+#define R_X86_64_DTPMOD64       16
+#define R_X86_64_DTPOFF64       17
+#define R_X86_64_TPOFF64        18
+#define R_X86_64_TLSGD          19
+#define R_X86_64_TLSLD          20
+#define R_X86_64_DTPOFF32       21
+#define R_X86_64_GOTTPOFF       22
+#define R_X86_64_TPOFF32        23
+#define R_X86_64_PC64           24
+#define R_X86_64_GOTOFF64       25
+#define R_X86_64_GOTPC32        26
+#define R_X86_64_GOT64          27
+#define R_X86_64_GOTPCREL64     28
+#define R_X86_64_GOTPC64        29
+#define R_X86_64_GOTPLT64       30
+#define R_X86_64_PLTOFF64       31
+#define R_X86_64_SIZE32         32
+#define R_X86_64_SIZE64         33
+// TODO
+#define R_X86_64_NUM            43
+
+typedef struct {
+        uint8_t e_ident[16];
+        uint16_t e_type;
+        uint16_t e_machine;
+        uint32_t e_version;
+        uint32_t e_entry;
+        uint32_t e_phoff;
+        uint32_t e_shoff;
+        uint32_t e_flags;
+        uint16_t e_ehsize;
+        uint16_t e_phentsize;
+        uint16_t e_phnum;
+        uint16_t e_shentsize;
+        uint16_t e_shnum;
+        uint16_t e_shstrndx;
+} Elf32_Ehdr;
+
+typedef struct {
+        uint8_t e_ident[16];
+        uint16_t e_type;
+        uint16_t e_machine;
+        uint32_t e_version;
+        uint64_t e_entry;
+        uint64_t e_phoff;
+        uint64_t e_shoff;
+        uint32_t e_flags;
+        uint16_t e_ehsize;
+        uint16_t e_phentsize;
+        uint16_t e_phnum;
+        uint16_t e_shentsize;
+        uint16_t e_shnum;
+        uint16_t e_shstrndx;
+} Elf64_Ehdr;
+
+typedef struct {
+        uint32_t p_type;
+        uint32_t p_flags;
+        uint32_t p_offset;
+        uint32_t p_vaddr;
+        uint32_t p_paddr;
+        uint32_t p_filesz;
+        uint32_t p_memsz;
+        uint32_t p_align;
+} Elf32_Phdr;
+
+typedef struct {
+        uint32_t p_type;
+        uint32_t p_flags;
+        uint64_t p_offset;
+        uint64_t p_vaddr;
+        uint64_t p_paddr;
+        uint64_t p_filesz;
+        uint64_t p_memsz;
+        uint64_t p_align;
+} Elf64_Phdr;
+
+typedef struct {
+        uint32_t r_offset;
+        uint32_t r_info;
+} Elf32_Rel;
+
+typedef struct {
+        uint64_t r_offset;
+        uint64_t r_info;
+} Elf64_Rel;
+
+#endif
diff --git a/include/limits.h b/include/limits.h
new file mode 100644
index 0000000..6ee065d
--- /dev/null
+++ b/include/limits.h
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2025 Danny Holman <dholman@gymli.org>
+ *
+ * This file is part of BoxOS, a free and open-source Unix-like operating
+ * system.
+ *
+ * BoxOS is free software; you can redistribute it and/or modify under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * BoxOS is distributed in the hope it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * BoxOS; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIMITS_H
+#define LIMITS_H
+
+#define CHAR_BIT        8
+#define SCHAR_MIN       (-128)
+#define SCHAR_MAX       127
+#define UCHAR_MAX       255
+
+#define CHAR_MIN        SCHAR_MIN
+#define CHAR_MAX        SCHAR_MAX
+
+#define SHRT_MIN        (-32768)
+#define SHRT_MAX        32767
+#define USHRT_MAX       65535
+
+#define INT_MIN         (-2147483648)
+#define INT_MAX         2147483647
+#define UINT_MAX        4294967295U
+
+#define LONG_MIN        (-9223372036854775808L)
+#define LONG_MAX        9223372036854775807L
+#define ULONG_MAX       18446744073709551615UL
+
+#define FLT_RADIX       2
+#define FLT_MANT_DIG    24
+#define FLT_DIG         6
+#define FLT_MIN         1.175494351e-38F
+#define FLT_MAX         3.402823466e+38F
+
+#define DBL_MANT_DIG    53
+#define DBL_DIG         15
+#define DBL_MIN         2.2250738585072014e-308
+#define DBL_MAX         1.7976931348623157e+308
+
+#define INT8_MIN        (-1-0x7F)
+#define INT16_MIN       (-1-0x7FFF)
+#define INT32_MIN       (-1-0x7FFFFFFF)
+#define INT64_MIN       (-1-0x7FFFFFFFFFFFFFFF)
+
+#define INT8_MAX        (0x7F)
+#define INT16_MAX       (0x7FFF)
+#define INT32_MAX       (0x7FFFFFFF)
+#define INT64_MAX       (0x7FFFFFFFFFFFFFFF)
+
+#define UINT8_MAX       (0xFF)
+#define UINT16_MAX      (0xFFFF)
+#define UINT32_MAX      (0xFFFFFFFF)
+#define UINT64_MAX      (0xFFFFFFFFFFFFFFFF)
+
+#define INTPTR_MAX      INT64_MAX
+#define UINTPTR_MAX     UINT64_MAX
+
+#define INT_FAST8_MIN   INT8_MIN
+#define INT_FAST64_MIN  INT64_MIN
+
+#define INT_FAST8_MAX   INT8_MAX
+#define INT_FAST64_MAX  INT64_MAX
+
+#define INT_LEAST8_MIN  INT8_MIN
+#define INT_LEAST16_MIN INT16_MIN
+#define INT_LEAST32_MIN INT32_MIN
+#define INT_LEAST64_MIN INT64_MIN
+
+#endif
diff --git a/include/stddef.h b/include/stddef.h
new file mode 100644
index 0000000..f391a3a
--- /dev/null
+++ b/include/stddef.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2025 Danny Holman <dholman@gymli.org>
+ *
+ * This file is part of BoxOS, a free and open-source Unix-like operating
+ * system.
+ *
+ * BoxOS is free software; you can redistribute it and/or modify under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * BoxOS is distributed in the hope it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * BoxOS; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef STDDEF_H
+#define STDDEF_H
+
+#include <stdint.h>
+
+#ifndef NULL
+#define NULL ((void*)0)
+#endif
+
+#if defined(__x86_64__) || defined(__aarch64__) || defined(__zarch__) || __riscv_xlen == 64
+typedef __int64_t               ptrdiff_t;
+typedef __int64_t               ssize_t;
+typedef __uint64_t              size_t;
+typedef __uint32_t              wchar_t;
+#elif defined(__i386__) || defined(__arm__) || __riscv_xlen == 32
+typedef __int32_t               ptrdiff_t;
+typedef __int32_t               ssize_t;
+typedef __uint32_t              size_t;
+typedef __uint16_t              wchar_t;
+#else
+#error "Unsupported architecture"
+#endif
+
+#define SIZE_MAX                ((size_t)65535)
+#define offsetof(type, member)  ((size_t)((char*)&(((type*)0)->member) - (char*)0))
+
+#endif
diff --git a/include/stdint.h b/include/stdint.h
new file mode 100644
index 0000000..c2328f8
--- /dev/null
+++ b/include/stdint.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2025 Danny Holman <dholman@gymli.org>
+ *
+ * This file is part of BoxOS, a free and open-source Unix-like operating
+ * system.
+ *
+ * BoxOS is free software; you can redistribute it and/or modify under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * BoxOS is distributed in the hope it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * BoxOS; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef STDINT_H
+#define STDINT_H
+
+typedef unsigned char           __u_char;
+typedef unsigned short          __u_short;
+typedef unsigned int            __u_int;
+
+typedef signed char             __int8_t;
+typedef signed short int        __int16_t;
+typedef signed int              __int32_t;
+
+typedef __u_char                __uint8_t;
+typedef __u_short               __uint16_t;
+typedef __u_int                 __uint32_t;
+
+#if defined(__x86_64__) || defined(__aarch64__) || defined(__zarch__) || __riscv_xlen == 64
+typedef unsigned long long      __u_long;
+typedef signed long long        __int64_t;
+typedef __u_long                __uint64_t;
+typedef __int64_t               intptr_t;
+typedef __uint64_t              uintptr_t;
+#elif defined(__i386__) || defined(__arm__) || __riscv_xlen == 32
+typedef unsigned long           __u_long;
+typedef signed long             __int64_t;
+typedef __u_long                __uint64_t;
+typedef __int32_t               intptr_t;
+typedef __uint32_t              uintptr_t;
+#else
+#error "Unsupported architecture"
+#endif
+
+typedef __int8_t                __int_least8_t;
+typedef __int16_t               __int_least16_t;
+typedef __int32_t               __int_least32_t;
+typedef __int64_t               __int_least64_t;
+
+typedef __uint8_t               __uint_least8_t;
+typedef __uint16_t              __uint_least16_t;
+typedef __uint32_t              __uint_least32_t;
+typedef __uint64_t              __uint_least64_t;
+
+typedef __int_least8_t          int8_t;
+typedef __int_least16_t         int16_t;
+typedef __int_least32_t         int32_t;
+typedef __int_least64_t         int64_t;
+
+typedef __uint_least8_t         uint8_t;
+typedef __uint_least16_t        uint16_t;
+typedef __uint_least32_t        uint32_t;
+typedef __uint_least64_t        uint64_t;
+
+#endif
diff --git a/include/string.h b/include/string.h
new file mode 100644
index 0000000..b7db629
--- /dev/null
+++ b/include/string.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2025 Danny Holman <dholman@gymli.org>
+ *
+ * This file is part of BoxOS, a free and open-source Unix-like operating
+ * system.
+ *
+ * BoxOS is free software; you can redistribute it and/or modify under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * BoxOS is distributed in the hope it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * BoxOS; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef STRING_H
+#define STRING_H
+
+#include <stddef.h>
+
+int memcmp(const void *str1, const void *str2, size_t n);
+void* memcpy(void* __restrict dest, const void* __restrict src, size_t n);
+void* memmove(void* __restrict dest, const void* __restrict src, size_t n);
+void* memset(void *str, int c, size_t n);
+
+int strcmp(const char *str1, const char *str2);
+int strncmp(const char *str1, const char *str2, size_t n);
+size_t strlen(const char *str);
+char* strncpy(char* __restrict dest, const char* __restrict src, size_t n);
+char* strcpy(char* __restrict dest, const char* __restrict src);
+char* strncat(char* __restrict dest, const char* __restrict src, size_t n);
+char* strcat(char* __restrict dest, const char* __restrict src);
+char* strtok(char* __restrict str, const char* __restrict delim);
+
+#endif