hw/loongarch: Add fw_cfg table support

Add fw_cfg table for loongarch virt machine, including memmap table.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Message-Id: <20220712083206.4187715-2-yangxiaojuan@loongson.cn>
[rth: Replace fprintf with assert; drop unused return value;
      initialize reserved slot to zero.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/hw/loongarch/fw_cfg.c b/hw/loongarch/fw_cfg.c
new file mode 100644
index 0000000..f6503d5
--- /dev/null
+++ b/hw/loongarch/fw_cfg.c
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * QEMU fw_cfg helpers (LoongArch specific)
+ *
+ * Copyright (C) 2021 Loongson Technology Corporation Limited
+ */
+
+#include "qemu/osdep.h"
+#include "hw/loongarch/fw_cfg.h"
+#include "hw/loongarch/virt.h"
+#include "hw/nvram/fw_cfg.h"
+#include "sysemu/sysemu.h"
+
+static void fw_cfg_boot_set(void *opaque, const char *boot_device,
+                            Error **errp)
+{
+    fw_cfg_modify_i16(opaque, FW_CFG_BOOT_DEVICE, boot_device[0]);
+}
+
+FWCfgState *loongarch_fw_cfg_init(ram_addr_t ram_size, MachineState *ms)
+{
+    FWCfgState *fw_cfg;
+    int max_cpus = ms->smp.max_cpus;
+    int smp_cpus = ms->smp.cpus;
+
+    fw_cfg = fw_cfg_init_mem_wide(VIRT_FWCFG_BASE + 8, VIRT_FWCFG_BASE, 8, 0, NULL);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_MAX_CPUS, (uint16_t)max_cpus);
+    fw_cfg_add_i64(fw_cfg, FW_CFG_RAM_SIZE, (uint64_t)ram_size);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
+
+    qemu_register_boot_set(fw_cfg_boot_set, fw_cfg);
+    return fw_cfg;
+}