1 files changed, 110 insertions, 0 deletions
diff --git a/kexec/arch/arm64/kexec-vmlinuz-arm64.c b/kexec/arch/arm64/kexec-vmlinuz-arm64.c
new file mode 100644
index 0000000..c0ee47c
--- /dev/null
+++ b/kexec/arch/arm64/kexec-vmlinuz-arm64.c
@@ -0,0 +1,110 @@
+/*
+ * ARM64 PE compressed Image (vmlinuz, ZBOOT) support.
+ *
+ * Several distros use 'make zinstall' rule inside
+ * 'arch/arm64/boot/Makefile' to install the arm64
+ * ZBOOT compressed file inside the boot destination
+ * directory (for e.g. /boot).
+ *
+ * Currently we cannot use kexec_file_load() to load vmlinuz
+ * PE images that self decompress.
+ *
+ * To support ZBOOT, we should:
+ * a). Copy the compressed contents of vmlinuz to a temporary file.
+ * b). Decompress (gunzip-decompress) the contents inside the
+ *     temporary file.
+ * c). Validate the resulting image and write it back to the
+ *     temporary file.
+ * d). Pass the 'fd' of the temporary file to the kernel space.
+ *
+ * Note this, module doesn't provide a _load() function instead
+ * relying on image_arm64_load() to load the resulting decompressed
+ * image.
+ *
+ * So basically the kernel space still gets a decompressed
+ * kernel image to load via kexec-tools.
+ */
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include "kexec-arm64.h"
+#include <kexec-pe-zboot.h>
+#include "arch/options.h"
+
+static int kernel_fd = -1;
+
+/* Returns:
+ * -1 : in case of error/invalid format (not a valid PE+compressed ZBOOT format.
+ */
+int pez_arm64_probe(const char *kernel_buf, off_t kernel_size)
+{
+	int ret = -1;
+	const struct arm64_image_header *h;
+	char *buf;
+	off_t buf_sz;
+
+	buf = (char *)kernel_buf;
+	buf_sz = kernel_size;
+	if (!buf)
+		return -1;
+	h = (const struct arm64_image_header *)buf;
+
+	dbgprintf("%s: PROBE.\n", __func__);
+	if (buf_sz < sizeof(struct arm64_image_header)) {
+		dbgprintf("%s: Not large enough to be a PE image.\n", __func__);
+		return -1;
+	}
+	if (!arm64_header_check_pe_sig(h)) {
+		dbgprintf("%s: Not an PE image.\n", __func__);
+		return -1;
+	}
+
+	if (buf_sz < sizeof(struct arm64_image_header) + h->pe_header) {
+		dbgprintf("%s: PE image offset larger than image.\n", __func__);
+		return -1;
+	}
+
+	if (memcmp(&buf[h->pe_header],
+		   arm64_pe_machtype, sizeof(arm64_pe_machtype))) {
+		dbgprintf("%s: PE header doesn't match machine type.\n", __func__);
+		return -1;
+	}
+
+	ret = pez_prepare(buf, buf_sz, &kernel_fd);
+
+	if (!ret) {
+	    /* validate the arm64 specific header */
+	    struct arm64_image_header hdr_check;
+	    if (read(kernel_fd, &hdr_check, sizeof(hdr_check)) != sizeof(hdr_check))
+		goto bad_header;
+
+	    lseek(kernel_fd, 0, SEEK_SET);
+
+	    if (!arm64_header_check_magic(&hdr_check)) {
+		dbgprintf("%s: Bad arm64 image header.\n", __func__);
+		goto bad_header;
+	    }
+	}
+
+	return ret;
+bad_header:
+	close(kernel_fd);
+	free(buf);
+	return -1;
+}
+
+int pez_arm64_load(int argc, char **argv, const char *buf, off_t len,
+			struct kexec_info *info)
+{
+	info->kernel_fd = kernel_fd;
+	return image_arm64_load(argc, argv, buf, len, info);
+}
+
+void pez_arm64_usage(void)
+{
+	printf(
+"     An ARM64 vmlinuz, PE image of a compressed, little endian.\n"
+"     kernel, built with ZBOOT enabled.\n\n");
+}