kboot: Parse "anvram" partition start and size from ADT

"nvram" size depends on the iboot version. Monterey (12.3) and earlier
used 128k nvram partition but Ventura since at least 13.2 increased the
size to 1M. Parse the values from the ADT and fill and enable the node
in the device tree.

Signed-off-by: Janne Grunau <[email protected]>

src/kboot.c

@@ -729,6 +729,57 @@ static int dt_set_ipd(void)
     return 0;
 }
 
+#define NVRAM_START    0x700000
+#define NVRAM_MAX_SIZE SZ_1M
+
+static int dt_set_nvram(void)
+{
+    int adt_path[8];
+    u64 start, size;
+
+    int anode = adt_path_offset_trace(adt, "/arm-io/spi1/spinor/anvram", adt_path);
+    if (anode < 0) {
+        printf("ADT: nvram partition not found\n");
+        return 0;
+    }
+
+    int pp = 0;
+    while (adt_path[pp])
+        pp++;
+    adt_path[pp + 1] = 0;
+
+    int ret = adt_get_reg(adt, adt_path, "reg", 0, &start, &size);
+    if (ret < 0) {
+        printf("ADT: could not read nvram partition start/size\n");
+        return 0;
+    }
+
+    if (start != NVRAM_START || size > NVRAM_MAX_SIZE) {
+
+        printf("ADT: unexpected nvram partition start (0x%lx) size (0x%lx)\n", start, size);
+        return 0;
+    }
+
+    int node = fdt_path_offset(dt, "nvram");
+    if (node < 0) {
+        printf("DT: nvram alias/partition not found\n");
+        return 0;
+    }
+
+    fdt32_t reg[2];
+    fdt32_st(reg + 0, start);
+    fdt32_st(reg + 1, size);
+    if (fdt_setprop(dt, node, "reg", reg, sizeof(reg))) {
+        printf("FDT: couldn't set nvram.reg\n");
+        return 0;
+    }
+
+    if (fdt_setprop_string(dt, node, "status", "okay") < 0)
+        printf("FDT: failed to enable nvram partition node\n");
+
+    return 0;
+}
+
 static int dt_set_wifi(void)
 {
     int anode = adt_path_offset(adt, "/arm-io/wlan");
@@ -2096,6 +2147,8 @@ int kboot_prepare_dt(void *fdt)
         return -1;
     if (dt_set_multitouch())
         return -1;
+    if (dt_set_nvram())
+        return -1;
     if (dt_set_ipd())
         return -1;
     if (dt_disable_missing_devs("usb-drd", "usb@", 8))