On Mon, Oct 19, 2020 at 4:17 PM Palmer Dabbelt <pal...@dabbelt.com> wrote:
>
> On Tue, 13 Oct 2020 17:17:33 PDT (-0700), Alistair Francis wrote:
> > Instead of loading the kernel at a hardcoded start address, let's load
> > the kernel at the next alligned address after the end of the firmware.
> >
> > This should have no impact for current users of OpenSBI, but will
> > allow loading a noMMU kernel at the start of memory.
> >
> > Signed-off-by: Alistair Francis <alistair.fran...@wdc.com>
> > ---
> > include/hw/riscv/boot.h | 3 +++
> > hw/riscv/boot.c | 19 ++++++++++++++-----
> > hw/riscv/opentitan.c | 3 ++-
> > hw/riscv/sifive_e.c | 3 ++-
> > hw/riscv/sifive_u.c | 10 ++++++++--
> > hw/riscv/spike.c | 11 ++++++++---
> > hw/riscv/virt.c | 11 ++++++++---
> > 7 files changed, 45 insertions(+), 15 deletions(-)
> >
> > diff --git a/include/hw/riscv/boot.h b/include/hw/riscv/boot.h
> > index 2975ed1a31..0b01988727 100644
> > --- a/include/hw/riscv/boot.h
> > +++ b/include/hw/riscv/boot.h
> > @@ -25,6 +25,8 @@
> >
> > bool riscv_is_32_bit(MachineState *machine);
> >
> > +target_ulong riscv_calc_kernel_start_addr(MachineState *machine,
> > + target_ulong firmware_end_addr);
> > target_ulong riscv_find_and_load_firmware(MachineState *machine,
> > const char
> > *default_machine_firmware,
> > hwaddr firmware_load_addr,
> > @@ -34,6 +36,7 @@ target_ulong riscv_load_firmware(const char
> > *firmware_filename,
> > hwaddr firmware_load_addr,
> > symbol_fn_t sym_cb);
> > 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,
> > uint64_t kernel_entry, hwaddr *start);
> > diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
> > index 5dea644f47..9b3fe3fb1e 100644
> > --- a/hw/riscv/boot.c
> > +++ b/hw/riscv/boot.c
> > @@ -33,10 +33,8 @@
> > #include <libfdt.h>
> >
> > #if defined(TARGET_RISCV32)
> > -# define KERNEL_BOOT_ADDRESS 0x80400000
> > #define fw_dynamic_info_data(__val) cpu_to_le32(__val)
> > #else
> > -# define KERNEL_BOOT_ADDRESS 0x80200000
> > #define fw_dynamic_info_data(__val) cpu_to_le64(__val)
> > #endif
> >
> > @@ -49,6 +47,15 @@ bool riscv_is_32_bit(MachineState *machine)
> > }
> > }
> >
> > +target_ulong riscv_calc_kernel_start_addr(MachineState *machine,
> > + target_ulong firmware_end_addr) {
> > + if (riscv_is_32_bit(machine)) {
> > + return QEMU_ALIGN_UP(firmware_end_addr, 4 * MiB);
> > + } else {
> > + return QEMU_ALIGN_UP(firmware_end_addr, 2 * MiB);
> > + }
> > +}
> > +
> > target_ulong riscv_find_and_load_firmware(MachineState *machine,
> > const char
> > *default_machine_firmware,
> > hwaddr firmware_load_addr,
> > @@ -123,7 +130,9 @@ target_ulong riscv_load_firmware(const char
> > *firmware_filename,
> > exit(1);
> > }
> >
> > -target_ulong riscv_load_kernel(const char *kernel_filename, symbol_fn_t
> > sym_cb)
> > +target_ulong riscv_load_kernel(const char *kernel_filename,
> > + target_ulong kernel_start_addr,
> > + symbol_fn_t sym_cb)
> > {
> > uint64_t kernel_entry;
> >
> > @@ -138,9 +147,9 @@ target_ulong riscv_load_kernel(const char
> > *kernel_filename, symbol_fn_t sym_cb)
> > return kernel_entry;
> > }
> >
> > - if (load_image_targphys_as(kernel_filename, KERNEL_BOOT_ADDRESS,
> > + if (load_image_targphys_as(kernel_filename, kernel_start_addr,
> > ram_size, NULL) > 0) {
> > - return KERNEL_BOOT_ADDRESS;
> > + return kernel_start_addr;
> > }
> >
> > error_report("could not load kernel '%s'", kernel_filename);
> > diff --git a/hw/riscv/opentitan.c b/hw/riscv/opentitan.c
> > index 0531bd879b..cc758b78b8 100644
> > --- a/hw/riscv/opentitan.c
> > +++ b/hw/riscv/opentitan.c
> > @@ -75,7 +75,8 @@ static void opentitan_board_init(MachineState *machine)
> > }
> >
> > if (machine->kernel_filename) {
> > - riscv_load_kernel(machine->kernel_filename, NULL);
> > + riscv_load_kernel(machine->kernel_filename,
> > + memmap[IBEX_DEV_RAM].base, NULL);
> > }
> > }
> >
> > diff --git a/hw/riscv/sifive_e.c b/hw/riscv/sifive_e.c
> > index fcfac16816..59bac4cc9a 100644
> > --- a/hw/riscv/sifive_e.c
> > +++ b/hw/riscv/sifive_e.c
> > @@ -114,7 +114,8 @@ static void sifive_e_machine_init(MachineState *machine)
> > memmap[SIFIVE_E_DEV_MROM].base,
> > &address_space_memory);
> >
> > if (machine->kernel_filename) {
> > - riscv_load_kernel(machine->kernel_filename, NULL);
> > + riscv_load_kernel(machine->kernel_filename,
> > + memmap[SIFIVE_E_DEV_DTIM].base, NULL);
> > }
> > }
> >
> > diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
> > index 5f3ad9bc0f..b2472c6627 100644
> > --- a/hw/riscv/sifive_u.c
> > +++ b/hw/riscv/sifive_u.c
> > @@ -415,6 +415,7 @@ static void sifive_u_machine_init(MachineState *machine)
> > MemoryRegion *main_mem = g_new(MemoryRegion, 1);
> > MemoryRegion *flash0 = g_new(MemoryRegion, 1);
> > target_ulong start_addr = memmap[SIFIVE_U_DEV_DRAM].base;
> > + target_ulong firmware_end_addr, kernel_start_addr;
> > uint32_t start_addr_hi32 = 0x00000000;
> > int i;
> > uint32_t fdt_load_addr;
> > @@ -474,10 +475,15 @@ static void sifive_u_machine_init(MachineState
> > *machine)
> > break;
> > }
> >
> > - riscv_find_and_load_firmware(machine, BIOS_FILENAME, start_addr, NULL);
> > + firmware_end_addr = riscv_find_and_load_firmware(machine,
> > BIOS_FILENAME,
> > + start_addr, NULL);
> >
> > if (machine->kernel_filename) {
> > - kernel_entry = riscv_load_kernel(machine->kernel_filename, NULL);
> > + kernel_start_addr = riscv_calc_kernel_start_addr(machine,
> > +
> > firmware_end_addr);
> > +
> > + kernel_entry = riscv_load_kernel(machine->kernel_filename,
> > + kernel_start_addr, NULL);
> >
> > if (machine->initrd_filename) {
> > hwaddr start;
> > diff --git a/hw/riscv/spike.c b/hw/riscv/spike.c
> > index 3fd152a035..facac6e7d2 100644
> > --- a/hw/riscv/spike.c
> > +++ b/hw/riscv/spike.c
> > @@ -195,6 +195,7 @@ static void spike_board_init(MachineState *machine)
> > MemoryRegion *system_memory = get_system_memory();
> > MemoryRegion *main_mem = g_new(MemoryRegion, 1);
> > MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
> > + target_ulong firmware_end_addr, kernel_start_addr;
> > uint32_t fdt_load_addr;
> > uint64_t kernel_entry;
> > char *soc_name;
> > @@ -261,12 +262,16 @@ static void spike_board_init(MachineState *machine)
> > memory_region_add_subregion(system_memory, memmap[SPIKE_MROM].base,
> > mask_rom);
> >
> > - riscv_find_and_load_firmware(machine, BIOS_FILENAME,
> > - memmap[SPIKE_DRAM].base,
> > - htif_symbol_callback);
> > + firmware_end_addr = riscv_find_and_load_firmware(machine,
> > BIOS_FILENAME,
> > +
> > memmap[SPIKE_DRAM].base,
> > + htif_symbol_callback);
> >
> > if (machine->kernel_filename) {
> > + kernel_start_addr = riscv_calc_kernel_start_addr(machine,
> > +
> > firmware_end_addr);
> > +
> > kernel_entry = riscv_load_kernel(machine->kernel_filename,
> > + kernel_start_addr,
> > htif_symbol_callback);
> >
> > if (machine->initrd_filename) {
> > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> > index 41bd2f38ba..6bfd10dfc7 100644
> > --- a/hw/riscv/virt.c
> > +++ b/hw/riscv/virt.c
> > @@ -493,6 +493,7 @@ static void virt_machine_init(MachineState *machine)
> > char *plic_hart_config, *soc_name;
> > size_t plic_hart_config_len;
> > target_ulong start_addr = memmap[VIRT_DRAM].base;
> > + target_ulong firmware_end_addr, kernel_start_addr;
> > uint32_t fdt_load_addr;
> > uint64_t kernel_entry;
> > DeviceState *mmio_plic, *virtio_plic, *pcie_plic;
> > @@ -602,11 +603,15 @@ static void virt_machine_init(MachineState *machine)
> > memory_region_add_subregion(system_memory, memmap[VIRT_MROM].base,
> > mask_rom);
> >
> > - riscv_find_and_load_firmware(machine, BIOS_FILENAME,
> > - memmap[VIRT_DRAM].base, NULL);
> > + firmware_end_addr = riscv_find_and_load_firmware(machine,
> > BIOS_FILENAME,
> > + start_addr, NULL);
> >
> > if (machine->kernel_filename) {
> > - kernel_entry = riscv_load_kernel(machine->kernel_filename, NULL);
> > + kernel_start_addr = riscv_calc_kernel_start_addr(machine,
> > +
> > firmware_end_addr);
> > +
> > + kernel_entry = riscv_load_kernel(machine->kernel_filename,
> > + kernel_start_addr, NULL);
> >
> > if (machine->initrd_filename) {
> > hwaddr start;
>
> It's probably worth going through and making sure we mark the right regions as
> reserved in the DT, as with these being mobile we might run into latent bugs.
Do you mean mark where the firmware is as reserved?
> I haven't actually looked so maybe we're fine, but IIRC we sort of papered
> over
> a handful of memory layout agreements that weren't even in specs (or event
> meant to be in specs) that have stuck around for quite a while.
For the virt machine or the sifive_u?
>
> Reviewed-by: Palmer Dabbelt <palmerdabb...@google.com>
Thanks
Alistair
