diff --git a/Makefile b/Makefile
index b544970d..79c87e12 100644
--- a/Makefile
+++ b/Makefile
@@ -39,6 +39,7 @@ OBJECTS := \
 	adt.o \
 	bootlogo_128.o bootlogo_256.o \
 	chickens.o \
+	cpio.o \
 	dart.o \
 	exception.o exception_asm.o \
 	fb.o font.o font_retina.o \
diff --git a/src/cpio.c b/src/cpio.c
new file mode 100644
index 00000000..0c8c8401
--- /dev/null
+++ b/src/cpio.c
@@ -0,0 +1,147 @@
+/* SPDX-License-Identifier: MIT */
+
+#include <string.h>
+
+#include "cpio.h"
+#include "malloc.h"
+#include "types.h"
+#include "utils.h"
+
+#define CPIO_MAX_FILES 20
+
+#define CPIO_MODE_DIR  0040755
+#define CPIO_MODE_FILE 0100644
+
+#define CPIO_HEADER_MAGIC "070701"
+
+struct cpio_header {
+    char magic[6];
+    char inode[8];
+    char mode[8];
+    char uid[8];
+    char gid[8];
+    char nlink[8];
+    char mtime[8];
+    char filesize[8];
+    char devmajor[8];
+    char devminor[8];
+    char rdevmajor[8];
+    char rdevminor[8];
+    char namesize[8];
+    char checksum[8];
+} PACKED;
+
+struct cpio {
+    u32 n_files;
+    struct {
+        const u8 *ptr;
+        size_t sz;
+        const char *name;
+        size_t name_sz;
+        struct cpio_header hdr;
+    } files[CPIO_MAX_FILES];
+};
+
+static char hex(u8 c)
+{
+    if (c <= 9)
+        return '0' + c;
+    return 'a' + c - 10;
+}
+
+static void write_hex32(char *p, u32 val)
+{
+    for (unsigned int i = 0; i < 8; ++i) {
+        u32 shift = 28 - (4 * i);
+        p[i] = hex((val >> shift) & 0xf);
+    }
+}
+
+struct cpio *cpio_init(void)
+{
+    struct cpio *c = malloc(sizeof(*c));
+    if (!c)
+        return NULL;
+
+    c->n_files = 0;
+    return c;
+}
+
+int cpio_add(struct cpio *c, const char *name, u64 mode, const u8 *bfr, size_t sz)
+{
+    struct cpio_header *hdr;
+
+    if (c->n_files >= CPIO_MAX_FILES) {
+        printf("cpio: cannot add more than %d files.\n", CPIO_MAX_FILES);
+        return -1;
+    }
+
+    c->files[c->n_files].ptr = bfr;
+    c->files[c->n_files].sz = sz;
+    c->files[c->n_files].name = name;
+    c->files[c->n_files].name_sz = strlen(name) + 1;
+
+    hdr = &c->files[c->n_files].hdr;
+    memcpy(hdr->magic, CPIO_HEADER_MAGIC, 6);
+    write_hex32(hdr->mode, mode);
+    write_hex32(hdr->nlink, 1);
+    write_hex32(hdr->filesize, sz);
+    write_hex32(hdr->namesize, strlen(name) + 1);
+
+    c->n_files++;
+
+    return 0;
+}
+
+int cpio_add_file(struct cpio *c, const char *name, const u8 *bfr, size_t sz)
+{
+    return cpio_add(c, name, CPIO_MODE_FILE, bfr, sz);
+}
+
+int cpio_add_dir(struct cpio *c, const char *name)
+{
+    return cpio_add(c, name, CPIO_MODE_DIR, NULL, 0);
+}
+
+size_t cpio_get_size(struct cpio *c)
+{
+    size_t sz = 0;
+
+    for (u32 i = 0; i < c->n_files; ++i) {
+        sz += sizeof(struct cpio_header);
+        sz += c->files[i].name_sz;
+        sz = ALIGN_UP(sz, 4);
+        sz += c->files[i].sz;
+        sz = ALIGN_UP(sz, 4);
+    }
+
+    return sz;
+}
+
+size_t cpio_finalize(struct cpio *c, u8 *bfr, size_t bfr_size)
+{
+    size_t off = 0;
+
+    if (cpio_get_size(c) > bfr_size)
+        return 0;
+
+    for (u32 i = 0; i < c->n_files; ++i) {
+        memcpy(bfr + off, &c->files[i].hdr, sizeof(struct cpio_header));
+        off += sizeof(struct cpio_header);
+
+        memcpy(bfr + off, c->files[i].name, c->files[i].name_sz);
+        off += c->files[i].name_sz;
+        off = ALIGN_UP(off, 4);
+
+        memcpy(bfr + off, c->files[i].ptr, c->files[i].sz);
+        off += c->files[i].sz;
+        off = ALIGN_UP(off, 4);
+    }
+
+    return off;
+}
+
+void cpio_free(struct cpio *c)
+{
+    free(c);
+}
diff --git a/src/cpio.h b/src/cpio.h
new file mode 100644
index 00000000..d32ca160
--- /dev/null
+++ b/src/cpio.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: MIT */
+
+#ifndef CPIO_H
+#define CPIO_H
+
+#include "types.h"
+#include "utils.h"
+
+struct cpio;
+
+struct cpio *cpio_init(void);
+int cpio_add_file(struct cpio *c, const char *name, const u8 *bfr, size_t sz);
+int cpio_add_dir(struct cpio *c, const char *name);
+size_t cpio_get_size(struct cpio *c);
+size_t cpio_finalize(struct cpio *c, u8 *bfr, size_t bfr_size);
+void cpio_free(struct cpio *c);
+
+#endif