[RFC 1/1] add support of `--initrd` for ELF-ARM kernels

[Stefan Lankes]

Currently, the flag `--initrd` is only support for Linux ARM kernels.
However, also other ELF kernels could depend on an initial ramdisk.
This PR loads also the initrd for ELF kernels and announce the
location by the nodes "/chosen/initrd-start" and
"/chosen/initrd-end" within the device tree.

Signed-off-by: Stefan Lankes <slankes@eonerc.rwth-aachen.de>
---
 hw/arm/boot.c | 106 +++++++++++++++++++++++++++++---------------------
 1 file changed, 62 insertions(+), 44 deletions(-)

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 54f6a3e0b3..f767a4809e 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -657,20 +657,38 @@ int arm_load_dtb(hwaddr addr, const struct arm_boot_info 
*binfo,
     }
 
     if (binfo->initrd_size) {
-        rc = qemu_fdt_setprop_sized_cells(fdt, "/chosen", "linux,initrd-start",
+        if (binfo->is_linux) {
+            rc = qemu_fdt_setprop_sized_cells(fdt, "/chosen", 
"linux,initrd-start",
                                           acells, binfo->initrd_start);
-        if (rc < 0) {
-            fprintf(stderr, "couldn't set /chosen/linux,initrd-start\n");
-            goto fail;
-        }
+            if (rc < 0) {
+                fprintf(stderr, "couldn't set /chosen/linux,initrd-start\n");
+                goto fail;
+            }
 
-        rc = qemu_fdt_setprop_sized_cells(fdt, "/chosen", "linux,initrd-end",
-                                          acells,
-                                          binfo->initrd_start +
-                                          binfo->initrd_size);
-        if (rc < 0) {
-            fprintf(stderr, "couldn't set /chosen/linux,initrd-end\n");
-            goto fail;
+            rc = qemu_fdt_setprop_sized_cells(fdt, "/chosen", 
"linux,initrd-end",
+                                              acells,
+                                              binfo->initrd_start +
+                                              binfo->initrd_size);
+            if (rc < 0) {
+                fprintf(stderr, "couldn't set /chosen/linux,initrd-end\n");
+                goto fail;
+            }
+        } else {
+            rc = qemu_fdt_setprop_sized_cells(fdt, "/chosen", "initrd-start",
+                                          acells, binfo->initrd_start);
+            if (rc < 0) {
+                fprintf(stderr, "couldn't set /chosen/initrd-start\n");
+                goto fail;
+            }
+
+            rc = qemu_fdt_setprop_sized_cells(fdt, "/chosen", "initrd-end",
+                                              acells,
+                                              binfo->initrd_start +
+                                              binfo->initrd_size);
+            if (rc < 0) {
+                fprintf(stderr, "couldn't set /chosen/initrd-end\n");
+                goto fail;
+            }
         }
     }
 
@@ -1099,41 +1117,41 @@ static void arm_setup_direct_kernel_boot(ARMCPU *cpu,
     }
     info->initrd_start = TARGET_PAGE_ALIGN(info->initrd_start);
 
-    if (is_linux) {
-        uint32_t fixupcontext[FIXUP_MAX];
-
-        if (info->initrd_filename) {
+    if (info->initrd_filename) {
 
-            if (info->initrd_start >= ram_end) {
-                error_report("not enough space after kernel to load initrd");
-                exit(1);
-            }
+        if (info->initrd_start >= ram_end) {
+            error_report("not enough space after kernel to load initrd");
+            exit(1);
+        }
 
-            initrd_size = load_ramdisk_as(info->initrd_filename,
-                                          info->initrd_start,
-                                          ram_end - info->initrd_start, as);
-            if (initrd_size < 0) {
-                initrd_size = load_image_targphys_as(info->initrd_filename,
-                                                     info->initrd_start,
-                                                     ram_end -
-                                                     info->initrd_start,
-                                                     as);
-            }
-            if (initrd_size < 0) {
-                error_report("could not load initrd '%s'",
-                             info->initrd_filename);
-                exit(1);
-            }
-            if (info->initrd_start + initrd_size > ram_end) {
-                error_report("could not load initrd '%s': "
-                             "too big to fit into RAM after the kernel",
-                             info->initrd_filename);
-                exit(1);
-            }
-        } else {
-            initrd_size = 0;
+        initrd_size = load_ramdisk_as(info->initrd_filename,
+                                      info->initrd_start,
+                                      ram_end - info->initrd_start, as);
+        if (initrd_size < 0) {
+            initrd_size = load_image_targphys_as(info->initrd_filename,
+                                                 info->initrd_start,
+                                                 ram_end -
+                                                 info->initrd_start,
+                                                 as);
+        }
+        if (initrd_size < 0) {
+            error_report("could not load initrd '%s'",
+                         info->initrd_filename);
+            exit(1);
+        }
+        if (info->initrd_start + initrd_size > ram_end) {
+            error_report("could not load initrd '%s': "
+                         "too big to fit into RAM after the kernel",
+                         info->initrd_filename);
+            exit(1);
         }
-        info->initrd_size = initrd_size;
+    } else {
+        initrd_size = 0;
+    }
+    info->initrd_size = initrd_size;
+
+    if (is_linux) {
+        uint32_t fixupcontext[FIXUP_MAX];
 
         fixupcontext[FIXUP_BOARDID] = info->board_id;
         fixupcontext[FIXUP_BOARD_SETUP] = info->board_setup_addr;
-- 
2.39.2 (Apple Git-143)