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[PATCH v4 2/4] RISC-V: Copy the fdt in dram instead of ROM
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From: |
Atish Patra |
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Subject: |
[PATCH v4 2/4] RISC-V: Copy the fdt in dram instead of ROM |
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Date: |
Wed, 1 Jul 2020 11:39:47 -0700 |
Currently, the fdt is copied to the ROM after the reset vector. The firmware
has to copy it to DRAM. Instead of this, directly copy the device tree to a
pre-computed dram address. The device tree load address should be as far as
possible from kernel and initrd images. That's why it is kept at the end of
the DRAM or 4GB whichever is lesser.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
hw/riscv/boot.c | 53 +++++++++++++++++++++++++++++------------
hw/riscv/sifive_u.c | 28 ++++++++++------------
hw/riscv/spike.c | 7 +++++-
hw/riscv/virt.c | 7 +++++-
include/hw/riscv/boot.h | 4 +++-
5 files changed, 66 insertions(+), 33 deletions(-)
diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
index 3df802380a36..c62f545f15e7 100644
--- a/hw/riscv/boot.c
+++ b/hw/riscv/boot.c
@@ -159,45 +159,68 @@ hwaddr riscv_load_initrd(const char *filename, uint64_t
mem_size,
return *start + size;
}
+uint32_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)
+{
+ uint32_t temp, fdt_addr;
+ hwaddr dram_end = dram_base + mem_size;
+ int fdtsize = fdt_totalsize(fdt);
+
+ if (fdtsize <= 0) {
+ error_report("invalid device-tree");
+ exit(1);
+ }
+
+ /*
+ * We should put fdt as far as possible to avoid kernel/initrd overwriting
+ * its content. But it should be addressable by 32 bit system as well.
+ * Thus, put it at an aligned address that less than fdt size from end of
+ * dram or 4GB whichever is lesser.
+ */
+ temp = MIN(dram_end, 4096 * MiB);
+ fdt_addr = QEMU_ALIGN_DOWN(temp - fdtsize, 2 * MiB);
+
+ fdt_pack(fdt);
+ /* copy in the device tree */
+ qemu_fdt_dumpdtb(fdt, fdtsize);
+
+ rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
+ &address_space_memory);
+
+ return fdt_addr;
+}
+
void riscv_setup_rom_reset_vec(hwaddr start_addr, hwaddr rom_base,
- hwaddr rom_size, void *fdt)
+ hwaddr rom_size,
+ uint32_t fdt_load_addr, void *fdt)
{
int i;
/* reset vector */
- uint32_t reset_vec[8] = {
+ uint32_t reset_vec[10] = {
0x00000297, /* 1: auipc t0, %pcrel_hi(dtb) */
- 0x02028593, /* addi a1, t0, %pcrel_lo(1b) */
0xf1402573, /* csrr a0, mhartid */
#if defined(TARGET_RISCV32)
+ 0x0202a583, /* lw a1, 32(t0) */
0x0182a283, /* lw t0, 24(t0) */
#elif defined(TARGET_RISCV64)
+ 0x0202b583, /* ld a1, 32(t0) */
0x0182b283, /* ld t0, 24(t0) */
#endif
0x00028067, /* jr t0 */
0x00000000,
start_addr, /* start: .dword */
+ 0x00000000,
+ fdt_load_addr, /* fdt_laddr: .dword */
0x00000000,
/* dtb: */
};
/* copy in the reset vector in little_endian byte order */
- for (i = 0; i < sizeof(reset_vec) >> 2; i++) {
+ for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
reset_vec[i] = cpu_to_le32(reset_vec[i]);
}
rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
rom_base, &address_space_memory);
- /* copy in the device tree */
- if (fdt_pack(fdt) || fdt_totalsize(fdt) >
- rom_size - sizeof(reset_vec)) {
- error_report("not enough space to store device-tree");
- exit(1);
- }
- qemu_fdt_dumpdtb(fdt, fdt_totalsize(fdt));
- rom_add_blob_fixed_as("mrom.fdt", fdt, fdt_totalsize(fdt),
- rom_base + sizeof(reset_vec),
- &address_space_memory);
-
return;
}
diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
index 395b21703ab4..aed814da9b94 100644
--- a/hw/riscv/sifive_u.c
+++ b/hw/riscv/sifive_u.c
@@ -379,6 +379,7 @@ static void sifive_u_machine_init(MachineState *machine)
MemoryRegion *flash0 = g_new(MemoryRegion, 1);
target_ulong start_addr = memmap[SIFIVE_U_DRAM].base;
int i;
+ uint32_t fdt_load_addr;
/* Initialize SoC */
object_initialize_child(OBJECT(machine), "soc", &s->soc, TYPE_RISCV_U_SOC);
@@ -450,40 +451,37 @@ static void sifive_u_machine_init(MachineState *machine)
}
}
+ /* Compute the fdt load address in dram */
+ fdt_load_addr = riscv_load_fdt(memmap[SIFIVE_U_DRAM].base,
+ machine->ram_size, s->fdt);
+
/* reset vector */
- uint32_t reset_vec[8] = {
+ uint32_t reset_vec[11] = {
s->msel, /* MSEL pin state */
0x00000297, /* 1: auipc t0, %pcrel_hi(dtb) */
- 0x01c28593, /* addi a1, t0, %pcrel_lo(1b) */
0xf1402573, /* csrr a0, mhartid */
#if defined(TARGET_RISCV32)
+ 0x0202a583, /* lw a1, 32(t0) */
0x0182a283, /* lw t0, 24(t0) */
#elif defined(TARGET_RISCV64)
- 0x0182e283, /* lwu t0, 24(t0) */
+ 0x0202b583, /* ld a1, 32(t0) */
+ 0x0182b283, /* ld t0, 24(t0) */
#endif
0x00028067, /* jr t0 */
0x00000000,
start_addr, /* start: .dword */
+ 0x00000000,
+ fdt_load_addr, /* fdt_laddr: .dword */
+ 0x00000000,
/* dtb: */
};
/* copy in the reset vector in little_endian byte order */
- for (i = 0; i < sizeof(reset_vec) >> 2; i++) {
+ for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
reset_vec[i] = cpu_to_le32(reset_vec[i]);
}
rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
memmap[SIFIVE_U_MROM].base, &address_space_memory);
-
- /* copy in the device tree */
- if (fdt_pack(s->fdt) || fdt_totalsize(s->fdt) >
- memmap[SIFIVE_U_MROM].size - sizeof(reset_vec)) {
- error_report("not enough space to store device-tree");
- exit(1);
- }
- qemu_fdt_dumpdtb(s->fdt, fdt_totalsize(s->fdt));
- rom_add_blob_fixed_as("mrom.fdt", s->fdt, fdt_totalsize(s->fdt),
- memmap[SIFIVE_U_MROM].base + sizeof(reset_vec),
- &address_space_memory);
}
static bool sifive_u_machine_get_start_in_flash(Object *obj, Error **errp)
diff --git a/hw/riscv/spike.c b/hw/riscv/spike.c
index c696077cbc16..5b04562dd106 100644
--- a/hw/riscv/spike.c
+++ b/hw/riscv/spike.c
@@ -163,6 +163,7 @@ static void spike_board_init(MachineState *machine)
MemoryRegion *main_mem = g_new(MemoryRegion, 1);
MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
unsigned int smp_cpus = machine->smp.cpus;
+ uint32_t fdt_load_addr;
/* Initialize SOC */
object_initialize_child(OBJECT(machine), "soc", &s->soc,
@@ -208,9 +209,13 @@ static void spike_board_init(MachineState *machine)
}
}
+ /* Compute the fdt load address in dram */
+ fdt_load_addr = riscv_load_fdt(memmap[SPIKE_DRAM].base,
+ machine->ram_size, s->fdt);
/* load the reset vector */
riscv_setup_rom_reset_vec(memmap[SPIKE_DRAM].base, memmap[SPIKE_MROM].base,
- memmap[SPIKE_MROM].size, s->fdt);
+ memmap[SPIKE_MROM].size,
+ fdt_load_addr, s->fdt);
/* initialize HTIF using symbols found in load_kernel */
htif_mm_init(system_memory, mask_rom, &s->soc.harts[0].env, serial_hd(0));
diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
index 8ec77e43de26..3b3cc44912f4 100644
--- a/hw/riscv/virt.c
+++ b/hw/riscv/virt.c
@@ -478,6 +478,7 @@ static void virt_machine_init(MachineState *machine)
char *plic_hart_config;
size_t plic_hart_config_len;
target_ulong start_addr = memmap[VIRT_DRAM].base;
+ uint32_t fdt_load_addr;
int i;
unsigned int smp_cpus = machine->smp.cpus;
@@ -532,9 +533,13 @@ static void virt_machine_init(MachineState *machine)
start_addr = virt_memmap[VIRT_FLASH].base;
}
+ /* Compute the fdt load address in dram */
+ fdt_load_addr = riscv_load_fdt(memmap[VIRT_DRAM].base,
+ machine->ram_size, s->fdt);
/* load the reset vector */
riscv_setup_rom_reset_vec(start_addr, virt_memmap[VIRT_MROM].base,
- virt_memmap[VIRT_MROM].size, s->fdt);
+ virt_memmap[VIRT_MROM].size,
+ fdt_load_addr, s->fdt);
/* create PLIC hart topology configuration string */
plic_hart_config_len = (strlen(VIRT_PLIC_HART_CONFIG) + 1) * smp_cpus;
diff --git a/include/hw/riscv/boot.h b/include/hw/riscv/boot.h
index 3e9759c89aa2..35b6ddf710d7 100644
--- a/include/hw/riscv/boot.h
+++ b/include/hw/riscv/boot.h
@@ -35,7 +35,9 @@ target_ulong riscv_load_kernel(const char *kernel_filename,
symbol_fn_t sym_cb);
hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
uint64_t kernel_entry, hwaddr *start);
+uint32_t riscv_load_fdt(hwaddr dram_start, uint64_t dram_size, void *fdt);
void riscv_setup_rom_reset_vec(hwaddr saddr, hwaddr rom_base,
- hwaddr rom_size, void *fdt);
+ hwaddr rom_size,
+ uint32_t fdt_load_addr, void *fdt);
#endif /* RISCV_BOOT_H */
--
2.26.2