otrx: optimize memory usage when creating TRX image

[openwrt/openwrt.git] / package / utils / otrx / src / otrx.c

diff --git a/package/utils/otrx/src/otrx.c b/package/utils/otrx/src/otrx.c
index 7b02977abbf41d8a8acd26f134fb6ab66d367fae..d08507f685cbbd4c8ab943826f1737c0a61dba9e 100644 (file)
--- a/package/utils/otrx/src/otrx.c
+++ b/package/utils/otrx/src/otrx.c
@@ -284,7 +284,7 @@ static ssize_t otrx_create_align(FILE *trx, size_t curr_offset, size_t alignment
 
 static int otrx_create_write_hdr(FILE *trx, struct trx_header *hdr) {
        size_t bytes, length;
-       uint8_t *buf;
+       uint8_t buf[1024];
        uint32_t crc32;
 
        hdr->magic = cpu_to_le32(TRX_MAGIC);
@@ -299,20 +299,13 @@ static int otrx_create_write_hdr(FILE *trx, struct trx_header *hdr) {
 
        length = le32_to_cpu(hdr->length);
 
-       buf = malloc(length);
-       if (!buf) {
-               fprintf(stderr, "Couldn't alloc %zu B buffer\n", length);
-               return -ENOMEM;
-       }
-
-       fseek(trx, 0, SEEK_SET);
-       bytes = fread(buf, 1, length, trx);
-       if (bytes != length) {
-               fprintf(stderr, "Couldn't read %zu B of data from %s\n", length, trx_path);
-               return -ENOMEM;
+       crc32 = 0xffffffff;
+       fseek(trx, TRX_FLAGS_OFFSET, SEEK_SET);
+       length -= TRX_FLAGS_OFFSET;
+       while ((bytes = fread(buf, 1, otrx_min(sizeof(buf), length), trx)) > 0) {
+               crc32 = otrx_crc32(crc32, buf, bytes);
+               length -= bytes;
        }
-
-       crc32 = otrx_crc32(0xffffffff, buf + TRX_FLAGS_OFFSET, length - TRX_FLAGS_OFFSET);
        hdr->crc32 = cpu_to_le32(crc32);
 
        fseek(trx, 0, SEEK_SET);