ppc/amigaone: Add default environment

Initialise empty NVRAM with default values. This also enables IDE UDMA
mode in AmigaOS that is faster but has to be enabled in environment
due to problems with real hardware but that does not affect emulation
so we can use faster defaults here.

Signed-off-by: BALATON Zoltan <[email protected]>
Reviewed-by: Nicholas Piggin <[email protected]>
Message-ID: <4d63f88191612329e0ca8102c7c0d4fc626dc372.1740673173.git.balaton@eik.bme.hu>
Signed-off-by: Nicholas Piggin <[email protected]>

Author: zbalaton

hw/ppc/amigaone.c

@@ -52,6 +52,28 @@ static const char dummy_fw[] = {
 #define NVRAM_ADDR 0xfd0e0000
 #define NVRAM_SIZE (4 * KiB)
 
+static char default_env[] =
+    "baudrate=115200\0"
+    "stdout=vga\0"
+    "stdin=ps2kbd\0"
+    "bootcmd=boota; menu; run menuboot_cmd\0"
+    "boot1=ide\0"
+    "boot2=cdrom\0"
+    "boota_timeout=3\0"
+    "ide_doreset=on\0"
+    "pci_irqa=9\0"
+    "pci_irqa_select=level\0"
+    "pci_irqb=10\0"
+    "pci_irqb_select=level\0"
+    "pci_irqc=11\0"
+    "pci_irqc_select=level\0"
+    "pci_irqd=7\0"
+    "pci_irqd_select=level\0"
+    "a1ide_irq=1111\0"
+    "a1ide_xfer=FFFF\0";
+#define CRC32_DEFAULT_ENV 0xb5548481
+#define CRC32_ALL_ZEROS   0x603b0489
+
 #define TYPE_A1_NVRAM "a1-nvram"
 OBJECT_DECLARE_SIMPLE_TYPE(A1NVRAMState, A1_NVRAM)
 
@@ -94,7 +116,7 @@ static void nvram_realize(DeviceState *dev, Error **errp)
 {
     A1NVRAMState *s = A1_NVRAM(dev);
     void *p;
-    uint32_t *c;
+    uint32_t crc, *c;
 
     memory_region_init_rom_device(&s->mr, NULL, &nvram_ops, s, "nvram",
                                   NVRAM_SIZE, &error_fatal);
@@ -113,12 +135,25 @@ static void nvram_realize(DeviceState *dev, Error **errp)
             return;
         }
     }
+    crc = crc32(0, p + 4, NVRAM_SIZE - 4);
+    if (crc == CRC32_ALL_ZEROS) { /* If env is uninitialized set default */
+        *c = cpu_to_be32(CRC32_DEFAULT_ENV);
+        /* Also copies terminating \0 as env is terminated by \0\0 */
+        memcpy(p + 4, default_env, sizeof(default_env));
+        if (s->blk) {
+            blk_pwrite(s->blk, 0, sizeof(crc) + sizeof(default_env), p, 0);
+        }
+        return;
+    }
     if (*c == 0) {
         *c = cpu_to_be32(crc32(0, p + 4, NVRAM_SIZE - 4));
         if (s->blk) {
             blk_pwrite(s->blk, 0, 4, p, 0);
         }
     }
+    if (be32_to_cpu(*c) != crc) {
+        warn_report("NVRAM checksum mismatch");
+    }
 }
 
 static const Property nvram_properties[] = {