hw/core/loader: allow loading larger ROMs

hw/core/loader: allow loading larger ROMs

The read() syscall is not guaranteed to return all data from a file. The
default ROM loader implementation currently does not take this into account,
instead failing if all bytes are not read at once. This change loads the ROM
using g_file_get_contents() instead, which correctly reads all data using
multiple calls to read() while also returning the loaded ROM size.

Signed-off-by: Gregor Haas <gregorhaas1997@gmail.com>
Reviewed-by: Xingtao Yao <yaoxt.fnst@fujitsu.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240628182706.99525-1-gregorhaas1997@gmail.com>
[PMD: Use gsize with g_file_get_contents()]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>