1 files changed, 68 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/zboot-decompress-gzip.c b/drivers/firmware/efi/libstub/zboot-decompress-gzip.c
new file mode 100644
index 000000000000..e97a7e9d3c98
--- /dev/null
+++ b/drivers/firmware/efi/libstub/zboot-decompress-gzip.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/efi.h>
+#include <linux/zlib.h>
+
+#include <asm/efi.h>
+
+#include "efistub.h"
+
+#include "inftrees.c"
+#include "inffast.c"
+#include "inflate.c"
+
+extern unsigned char _gzdata_start[], _gzdata_end[];
+extern u32 __aligned(1) payload_size;
+
+static struct z_stream_s stream;
+
+efi_status_t efi_zboot_decompress_init(unsigned long *alloc_size)
+{
+	efi_status_t status;
+	int rc;
+
+	/* skip the 10 byte header, assume no recorded filename */
+	stream.next_in = _gzdata_start + 10;
+	stream.avail_in = _gzdata_end - stream.next_in;
+
+	status = efi_allocate_pages(zlib_inflate_workspacesize(),
+				    (unsigned long *)&stream.workspace,
+				    ULONG_MAX);
+	if (status != EFI_SUCCESS)
+		return status;
+
+	rc = zlib_inflateInit2(&stream, -MAX_WBITS);
+	if (rc != Z_OK) {
+		efi_err("failed to initialize GZIP decompressor: %d\n", rc);
+		status = EFI_LOAD_ERROR;
+		goto out;
+	}
+
+	*alloc_size = payload_size;
+	return EFI_SUCCESS;
+out:
+	efi_free(zlib_inflate_workspacesize(), (unsigned long)stream.workspace);
+	return status;
+}
+
+efi_status_t efi_zboot_decompress(u8 *out, unsigned long outlen)
+{
+	int rc;
+
+	stream.next_out = out;
+	stream.avail_out = outlen;
+
+	rc = zlib_inflate(&stream, 0);
+	zlib_inflateEnd(&stream);
+
+	efi_free(zlib_inflate_workspacesize(), (unsigned long)stream.workspace);
+
+	if (rc != Z_STREAM_END) {
+		efi_err("GZIP decompression failed with status %d\n", rc);
+		return EFI_LOAD_ERROR;
+	}
+
+	efi_cache_sync_image((unsigned long)out, outlen);
+
+	return EFI_SUCCESS;
+}