hw/riscv: Respect firmware ELF entry point

When riscv_load_firmware() loads an ELF, the ELF segment addresses are
used, not the passed-in firmware_load_addr. The machine models assume
the firmware entry point is what they provided for firmware_load_addr,
and use that address to generate the boot ROM, so if the ELF is linked
at any other address, the boot ROM will jump to empty memory.

Pass back the ELF entry point to use when generating the boot ROM, so
the boot ROM can jump to firmware loaded anywhere in RAM. For example,
on the virt machine, this allows using an OpenSBI fw_dynamic.elf built
with FW_TEXT_START values other than 0x80000000.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240817002651.3209701-1-samuel.holland@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

7 files changed, 22 insertions, 20 deletions

diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
index 47281ca..9115ecd 100644
--- a/hw/riscv/boot.c
+++ b/hw/riscv/boot.c
@@ -128,11 +128,11 @@ char *riscv_find_firmware(const char *firmware_filename,
 
 target_ulong riscv_find_and_load_firmware(MachineState *machine,
                                           const char *default_machine_firmware,
-                                          hwaddr firmware_load_addr,
+                                          hwaddr *firmware_load_addr,
                                           symbol_fn_t sym_cb)
 {
     char *firmware_filename;
-    target_ulong firmware_end_addr = firmware_load_addr;
+    target_ulong firmware_end_addr = *firmware_load_addr;
 
     firmware_filename = riscv_find_firmware(machine->firmware,
                                             default_machine_firmware);
@@ -148,7 +148,7 @@ target_ulong riscv_find_and_load_firmware(MachineState *machine,
 }
 
 target_ulong riscv_load_firmware(const char *firmware_filename,
-                                 hwaddr firmware_load_addr,
+                                 hwaddr *firmware_load_addr,
                                  symbol_fn_t sym_cb)
 {
     uint64_t firmware_entry, firmware_end;
@@ -159,15 +159,16 @@ target_ulong riscv_load_firmware(const char *firmware_filename,
     if (load_elf_ram_sym(firmware_filename, NULL, NULL, NULL,
                          &firmware_entry, NULL, &firmware_end, NULL,
                          0, EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
+        *firmware_load_addr = firmware_entry;
         return firmware_end;
     }
 
     firmware_size = load_image_targphys_as(firmware_filename,
-                                           firmware_load_addr,
+                                           *firmware_load_addr,
                                            current_machine->ram_size, NULL);
 
     if (firmware_size > 0) {
-        return firmware_load_addr + firmware_size;
+        return *firmware_load_addr + firmware_size;
     }
 
     error_report("could not load firmware '%s'", firmware_filename);
diff --git a/hw/riscv/microchip_pfsoc.c b/hw/riscv/microchip_pfsoc.c
index 7725dfb..f9a3b43 100644
--- a/hw/riscv/microchip_pfsoc.c
+++ b/hw/riscv/microchip_pfsoc.c
@@ -613,7 +613,7 @@ static void microchip_icicle_kit_machine_init(MachineState *machine)
 
     /* Load the firmware */
     firmware_end_addr = riscv_find_and_load_firmware(machine, firmware_name,
-                                                     firmware_load_addr, NULL);
+                                                     &firmware_load_addr, NULL);
 
     if (kernel_as_payload) {
         kernel_start_addr = riscv_calc_kernel_start_addr(&s->soc.u_cpus,
diff --git a/hw/riscv/opentitan.c b/hw/riscv/opentitan.c
index 436503f..e2830e9 100644
--- a/hw/riscv/opentitan.c
+++ b/hw/riscv/opentitan.c
@@ -98,7 +98,8 @@ static void opentitan_machine_init(MachineState *machine)
         memmap[IBEX_DEV_RAM].base, machine->ram);
 
     if (machine->firmware) {
-        riscv_load_firmware(machine->firmware, memmap[IBEX_DEV_RAM].base, NULL);
+        hwaddr firmware_load_addr = memmap[IBEX_DEV_RAM].base;
+        riscv_load_firmware(machine->firmware, &firmware_load_addr, NULL);
     }
 
     if (machine->kernel_filename) {
diff --git a/hw/riscv/shakti_c.c b/hw/riscv/shakti_c.c
index 3888034..2dccc1e 100644
--- a/hw/riscv/shakti_c.c
+++ b/hw/riscv/shakti_c.c
@@ -45,6 +45,7 @@ static void shakti_c_machine_state_init(MachineState *mstate)
 {
     ShaktiCMachineState *sms = RISCV_SHAKTI_MACHINE(mstate);
     MemoryRegion *system_memory = get_system_memory();
+    hwaddr firmware_load_addr = shakti_c_memmap[SHAKTI_C_RAM].base;
 
     /* Initialize SoC */
     object_initialize_child(OBJECT(mstate), "soc", &sms->soc,
@@ -56,16 +57,14 @@ static void shakti_c_machine_state_init(MachineState *mstate)
                                 shakti_c_memmap[SHAKTI_C_RAM].base,
                                 mstate->ram);
 
+    if (mstate->firmware) {
+        riscv_load_firmware(mstate->firmware, &firmware_load_addr, NULL);
+    }
+
     /* ROM reset vector */
-    riscv_setup_rom_reset_vec(mstate, &sms->soc.cpus,
-                              shakti_c_memmap[SHAKTI_C_RAM].base,
+    riscv_setup_rom_reset_vec(mstate, &sms->soc.cpus, firmware_load_addr,
                               shakti_c_memmap[SHAKTI_C_ROM].base,
                               shakti_c_memmap[SHAKTI_C_ROM].size, 0, 0);
-    if (mstate->firmware) {
-        riscv_load_firmware(mstate->firmware,
-                            shakti_c_memmap[SHAKTI_C_RAM].base,
-                            NULL);
-    }
 }
 
 static void shakti_c_machine_instance_init(Object *obj)
diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
index af5f923..35a6893 100644
--- a/hw/riscv/sifive_u.c
+++ b/hw/riscv/sifive_u.c
@@ -515,7 +515,7 @@ static void sifive_u_machine_init(MachineState *machine)
     SiFiveUState *s = RISCV_U_MACHINE(machine);
     MemoryRegion *system_memory = get_system_memory();
     MemoryRegion *flash0 = g_new(MemoryRegion, 1);
-    target_ulong start_addr = memmap[SIFIVE_U_DEV_DRAM].base;
+    hwaddr start_addr = memmap[SIFIVE_U_DEV_DRAM].base;
     target_ulong firmware_end_addr, kernel_start_addr;
     const char *firmware_name;
     uint32_t start_addr_hi32 = 0x00000000;
@@ -589,7 +589,7 @@ static void sifive_u_machine_init(MachineState *machine)
 
     firmware_name = riscv_default_firmware_name(&s->soc.u_cpus);
     firmware_end_addr = riscv_find_and_load_firmware(machine, firmware_name,
-                                                     start_addr, NULL);
+                                                     &start_addr, NULL);
 
     if (machine->kernel_filename) {
         kernel_start_addr = riscv_calc_kernel_start_addr(&s->soc.u_cpus,
diff --git a/hw/riscv/spike.c b/hw/riscv/spike.c
index 6407439..fceb91d 100644
--- a/hw/riscv/spike.c
+++ b/hw/riscv/spike.c
@@ -198,6 +198,7 @@ static void spike_board_init(MachineState *machine)
     MemoryRegion *system_memory = get_system_memory();
     MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
     target_ulong firmware_end_addr = memmap[SPIKE_DRAM].base;
+    hwaddr firmware_load_addr = memmap[SPIKE_DRAM].base;
     target_ulong kernel_start_addr;
     char *firmware_name;
     uint32_t fdt_load_addr;
@@ -290,7 +291,7 @@ static void spike_board_init(MachineState *machine)
     /* Load firmware */
     if (firmware_name) {
         firmware_end_addr = riscv_load_firmware(firmware_name,
-                                                memmap[SPIKE_DRAM].base,
+                                                &firmware_load_addr,
                                                 htif_symbol_callback);
         g_free(firmware_name);
     }
@@ -320,7 +321,7 @@ static void spike_board_init(MachineState *machine)
     riscv_load_fdt(fdt_load_addr, machine->fdt);
 
     /* load the reset vector */
-    riscv_setup_rom_reset_vec(machine, &s->soc[0], memmap[SPIKE_DRAM].base,
+    riscv_setup_rom_reset_vec(machine, &s->soc[0], firmware_load_addr,
                               memmap[SPIKE_MROM].base,
                               memmap[SPIKE_MROM].size, kernel_entry,
                               fdt_load_addr);
diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
index cef41c1..3c0dca8 100644
--- a/hw/riscv/virt.c
+++ b/hw/riscv/virt.c
@@ -1335,7 +1335,7 @@ static void virt_machine_done(Notifier *notifier, void *data)
                                      machine_done);
     const MemMapEntry *memmap = virt_memmap;
     MachineState *machine = MACHINE(s);
-    target_ulong start_addr = memmap[VIRT_DRAM].base;
+    hwaddr start_addr = memmap[VIRT_DRAM].base;
     target_ulong firmware_end_addr, kernel_start_addr;
     const char *firmware_name = riscv_default_firmware_name(&s->soc[0]);
     uint64_t fdt_load_addr;
@@ -1367,7 +1367,7 @@ static void virt_machine_done(Notifier *notifier, void *data)
     }
 
     firmware_end_addr = riscv_find_and_load_firmware(machine, firmware_name,
-                                                     start_addr, NULL);
+                                                     &start_addr, NULL);
 
     pflash_blk0 = pflash_cfi01_get_blk(s->flash[0]);
     if (pflash_blk0) {