Save memory allocation in the elf loader

The current elf loader uses too much memory. For example, I have a
executable with a bss section of 400 MB and I set the ram size to 512
MB. Qemu uses about 780MB of RAM (which is fine), but there's a peak at
1.6 GB during initialization (this is not fine).

This patch fixes two things:
 1) do not allocate each elf program twice.
 2) do not allocate memory for areas that are only zeros.

For this we need a new field in Rom: "datasize" which is the size of the
allocated data. If datasize is less than romsize, it means that the area
from datasize to romsize is filled with zeros.

Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/hw/loader.h b/hw/loader.h
index 5e61c95b84..0958f06934 100644
--- a/hw/loader.h
+++ b/hw/loader.h
@@ -27,6 +27,8 @@ int rom_add_file(const char *file, const char *fw_dir,
                  hwaddr addr, int32_t bootindex);
 int rom_add_blob(const char *name, const void *blob, size_t len,
                  hwaddr addr);
+int rom_add_elf_program(const char *name, void *data, size_t datasize,
+                        size_t romsize, hwaddr addr);
 int rom_load_all(void);
 void rom_set_fw(void *f);
 int rom_copy(uint8_t *dest, hwaddr addr, size_t size);