Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 102 insertions, 0 deletions

diff --git a/hw/nvram/chrp_nvram.c b/hw/nvram/chrp_nvram.c
new file mode 100644
index 000000000..d4d10a7c0
--- /dev/null
+++ b/hw/nvram/chrp_nvram.c
@@ -0,0 +1,102 @@
+/*
+ * Common Hardware Reference Platform NVRAM helper functions.
+ *
+ * The CHRP NVRAM layout is used by OpenBIOS and SLOF. See CHRP
+ * specification, chapter 8, or the LoPAPR specification for details
+ * about the NVRAM layout.
+ *
+ * This code is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2 of the License,
+ * or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/cutils.h"
+#include "qemu/error-report.h"
+#include "hw/nvram/chrp_nvram.h"
+#include "sysemu/sysemu.h"
+
+static int chrp_nvram_set_var(uint8_t *nvram, int addr, const char *str,
+                              int max_len)
+{
+    int len;
+
+    len = strlen(str) + 1;
+
+    if (max_len < len) {
+        return -1;
+    }
+
+    memcpy(&nvram[addr], str, len);
+
+    return addr + len;
+}
+
+/**
+ * Create a "system partition", used for the Open Firmware
+ * environment variables.
+ */
+int chrp_nvram_create_system_partition(uint8_t *data, int min_len, int max_len)
+{
+    ChrpNvramPartHdr *part_header;
+    unsigned int i;
+    int end;
+
+    if (max_len < sizeof(*part_header)) {
+        goto fail;
+    }
+
+    part_header = (ChrpNvramPartHdr *)data;
+    part_header->signature = CHRP_NVPART_SYSTEM;
+    pstrcpy(part_header->name, sizeof(part_header->name), "system");
+
+    end = sizeof(ChrpNvramPartHdr);
+    for (i = 0; i < nb_prom_envs; i++) {
+        end = chrp_nvram_set_var(data, end, prom_envs[i], max_len - end);
+        if (end == -1) {
+            goto fail;
+        }
+    }
+
+    /* End marker */
+    data[end++] = '\0';
+
+    end = (end + 15) & ~15;
+    /* XXX: OpenBIOS is not able to grow up a partition. Leave some space for
+       new variables. */
+    if (end < min_len) {
+        end = min_len;
+    }
+    chrp_nvram_finish_partition(part_header, end);
+
+    return end;
+
+fail:
+    error_report("NVRAM is too small. Try to pass less data to -prom-env");
+    exit(EXIT_FAILURE);
+}
+
+/**
+ * Create a "free space" partition
+ */
+int chrp_nvram_create_free_partition(uint8_t *data, int len)
+{
+    ChrpNvramPartHdr *part_header;
+
+    part_header = (ChrpNvramPartHdr *)data;
+    part_header->signature = CHRP_NVPART_FREE;
+    pstrcpy(part_header->name, sizeof(part_header->name), "free");
+
+    chrp_nvram_finish_partition(part_header, len);
+
+    return len;
+}