hw/riscv: write initrd 'chosen' FDT inside riscv_load_initrd()

riscv_load_initrd() returns the initrd end addr while also writing a
'start' var to mark the addr start. These informations are being used
just to write the initrd FDT node. Every existing caller of
riscv_load_initrd() is writing the FDT in the same manner.

We can simplify things by writing the FDT inside riscv_load_initrd(),
sparing callers from having to manage start/end addrs to write the FDT
themselves.

An 'if (fdt)' check is already inserted at the end of the function
because we'll end up using it later on with other boards that doesn´t
have a FDT.

Cc: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230102115241.25733-7-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

hw/riscv/boot.c

@@ -208,9 +208,10 @@ target_ulong riscv_load_kernel(const char *kernel_filename,
     exit(1);
 }
 
-hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
+void riscv_load_initrd(const char *filename, uint64_t mem_size,
-                         uint64_t kernel_entry, hwaddr *start)
+                       uint64_t kernel_entry, void *fdt)
 {
+    hwaddr start, end;
     ssize_t size;
 
     g_assert(filename != NULL);
@@ -226,18 +227,23 @@ hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
      * halfway into RAM, and for boards with 256MB of RAM or more we put
      * the initrd at 128MB.
      */
-    *start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
+    start = kernel_entry + MIN(mem_size / 2, 128 * MiB);
 
-    size = load_ramdisk(filename, *start, mem_size - *start);
+    size = load_ramdisk(filename, start, mem_size - start);
     if (size == -1) {
-        size = load_image_targphys(filename, *start, mem_size - *start);
+        size = load_image_targphys(filename, start, mem_size - start);
         if (size == -1) {
             error_report("could not load ramdisk '%s'", filename);
             exit(1);
         }
     }
 
-    return *start + size;
+    /* Some RISC-V machines (e.g. opentitan) don't have a fdt. */
+    if (fdt) {
+        end = start + size;
+        qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-start", start);
+        qemu_fdt_setprop_cell(fdt, "/chosen", "linux,initrd-end", end);
+    }
 }
 
 uint64_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)

hw/riscv/microchip_pfsoc.c

@@ -633,14 +633,8 @@ static void microchip_icicle_kit_machine_init(MachineState *machine)
                                          kernel_start_addr, NULL);
 
         if (machine->initrd_filename) {
-            hwaddr start;
+            riscv_load_initrd(machine->initrd_filename, machine->ram_size,
-            hwaddr end = riscv_load_initrd(machine->initrd_filename,
+                              kernel_entry, machine->fdt);
-                                           machine->ram_size, kernel_entry,
-                                           &start);
-            qemu_fdt_setprop_cell(machine->fdt, "/chosen",
-                                  "linux,initrd-start", start);
-            qemu_fdt_setprop_cell(machine->fdt, "/chosen",
-                                  "linux,initrd-end", end);
         }
 
         if (machine->kernel_cmdline && *machine->kernel_cmdline) {

hw/riscv/sifive_u.c

@@ -608,14 +608,8 @@ static void sifive_u_machine_init(MachineState *machine)
                                          kernel_start_addr, NULL);
 
         if (machine->initrd_filename) {
-            hwaddr start;
+            riscv_load_initrd(machine->initrd_filename, machine->ram_size,
-            hwaddr end = riscv_load_initrd(machine->initrd_filename,
+                              kernel_entry, machine->fdt);
-                                           machine->ram_size, kernel_entry,
-                                           &start);
-            qemu_fdt_setprop_cell(machine->fdt, "/chosen",
-                                  "linux,initrd-start", start);
-            qemu_fdt_setprop_cell(machine->fdt, "/chosen", "linux,initrd-end",
-                                  end);
         }
     } else {
        /*

hw/riscv/spike.c

@@ -316,14 +316,8 @@ static void spike_board_init(MachineState *machine)
                                          htif_symbol_callback);
 
         if (machine->initrd_filename) {
-            hwaddr start;
+            riscv_load_initrd(machine->initrd_filename, machine->ram_size,
-            hwaddr end = riscv_load_initrd(machine->initrd_filename,
+                              kernel_entry, machine->fdt);
-                                           machine->ram_size, kernel_entry,
-                                           &start);
-            qemu_fdt_setprop_cell(machine->fdt, "/chosen",
-                                  "linux,initrd-start", start);
-            qemu_fdt_setprop_cell(machine->fdt, "/chosen", "linux,initrd-end",
-                                  end);
         }
     } else {
        /*

hw/riscv/virt.c

@@ -1291,14 +1291,8 @@ static void virt_machine_done(Notifier *notifier, void *data)
                                          kernel_start_addr, NULL);
 
         if (machine->initrd_filename) {
-            hwaddr start;
+            riscv_load_initrd(machine->initrd_filename, machine->ram_size,
-            hwaddr end = riscv_load_initrd(machine->initrd_filename,
+                              kernel_entry, machine->fdt);
-                                           machine->ram_size, kernel_entry,
-                                           &start);
-            qemu_fdt_setprop_cell(machine->fdt, "/chosen",
-                                  "linux,initrd-start", start);
-            qemu_fdt_setprop_cell(machine->fdt, "/chosen", "linux,initrd-end",
-                                  end);
         }
     } else {
        /*

include/hw/riscv/boot.h

@@ -46,8 +46,8 @@ target_ulong riscv_load_firmware(const char *firmware_filename,
 target_ulong riscv_load_kernel(const char *kernel_filename,
                                target_ulong firmware_end_addr,
                                symbol_fn_t sym_cb);
-hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
+void riscv_load_initrd(const char *filename, uint64_t mem_size,
-                         uint64_t kernel_entry, hwaddr *start);
+                       uint64_t kernel_entry, void *fdt);
 uint64_t riscv_load_fdt(hwaddr dram_start, uint64_t dram_size, void *fdt);
 void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts,
                                hwaddr saddr,