From: "Richard W.M. Jones" Date: Tue, 19 Aug 2014 18:56:28 +0100 Subject: [PATCH] loader: Add load_image_gzipped function. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As the name suggests this lets you load a ROM/disk image that is gzipped. It is uncompressed before storing it in guest memory. Signed-off-by: Richard W.M. Jones Reviewed-by: Alex Bennée Reviewed-by: Peter Crosthwaite Reviewed-by: Alex Bennée Message-id: 1407831259-2115-2-git-send-email-rjones@redhat.com [PMM: removed stray space before ')'] Signed-off-by: Peter Maydell (cherry picked from commit 235e74afcb85285a8e35e75f0cb6e6811267bb75) --- hw/core/loader.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ include/hw/loader.h | 1 + 2 files changed, 49 insertions(+) diff --git a/hw/core/loader.c b/hw/core/loader.c index 2bf6b8f..0fde699 100644 --- a/hw/core/loader.c +++ b/hw/core/loader.c @@ -577,6 +577,54 @@ int load_ramdisk(const char *filename, hwaddr addr, uint64_t max_sz) return load_uboot_image(filename, NULL, &addr, NULL, IH_TYPE_RAMDISK); } +/* This simply prevents g_malloc in the function below from allocating + * a huge amount of memory, by placing a limit on the maximum + * uncompressed image size that load_image_gzipped will read. + */ +#define LOAD_IMAGE_MAX_GUNZIP_BYTES (256 << 20) + +/* Load a gzip-compressed kernel. */ +int load_image_gzipped(const char *filename, hwaddr addr, uint64_t max_sz) +{ + uint8_t *compressed_data = NULL; + uint8_t *data = NULL; + gsize len; + ssize_t bytes; + int ret = -1; + + if (!g_file_get_contents(filename, (char **) &compressed_data, &len, + NULL)) { + goto out; + } + + /* Is it a gzip-compressed file? */ + if (len < 2 || + compressed_data[0] != 0x1f || + compressed_data[1] != 0x8b) { + goto out; + } + + if (max_sz > LOAD_IMAGE_MAX_GUNZIP_BYTES) { + max_sz = LOAD_IMAGE_MAX_GUNZIP_BYTES; + } + + data = g_malloc(max_sz); + bytes = gunzip(data, max_sz, compressed_data, len); + if (bytes < 0) { + fprintf(stderr, "%s: unable to decompress gzipped kernel file\n", + filename); + goto out; + } + + rom_add_blob_fixed(filename, data, bytes, addr); + ret = bytes; + + out: + g_free(compressed_data); + g_free(data); + return ret; +} + /* * Functions for reboot-persistent memory regions. * - used for vga bios and option roms. diff --git a/include/hw/loader.h b/include/hw/loader.h index 796cbf9..00c9117 100644 --- a/include/hw/loader.h +++ b/include/hw/loader.h @@ -15,6 +15,7 @@ int get_image_size(const char *filename); int load_image(const char *filename, uint8_t *addr); /* deprecated */ int load_image_targphys(const char *filename, hwaddr, uint64_t max_sz); +int load_image_gzipped(const char *filename, hwaddr addr, uint64_t max_sz); #define ELF_LOAD_FAILED -1 #define ELF_LOAD_NOT_ELF -2