+Atish On Wed, Jun 8, 2022 at 2:20 PM Alistair Francis <alistair.fran...@opensource.wdc.com> wrote: > > From: Alistair Francis <alistair.fran...@wdc.com> > > We previously stored the device tree at a 16MB alignment from the end of > memory (or 3GB). This means we need at least 16MB of memory to be able > to do this. We don't actually need the FDT to be 16MB aligned, so let's > drop it down to 2MB so that we can support systems with less memory, > while also allowing FDT size expansion. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/992 > Signed-off-by: Alistair Francis <alistair.fran...@wdc.com> > --- > hw/riscv/boot.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c > index 57a41df8e9..e476d8f491 100644 > --- a/hw/riscv/boot.c > +++ b/hw/riscv/boot.c > @@ -226,11 +226,11 @@ uint64_t riscv_load_fdt(hwaddr dram_base, uint64_t > mem_size, void *fdt) > /* > * 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 16MB aligned address that less than fdt size from > the > + * Thus, put it at an 2MB aligned address that less than fdt size from > the > * end of dram or 3GB whichever is lesser. > */ > temp = (dram_base < 3072 * MiB) ? MIN(dram_end, 3072 * MiB) : dram_end; > - fdt_addr = QEMU_ALIGN_DOWN(temp - fdtsize, 16 * MiB); > + fdt_addr = QEMU_ALIGN_DOWN(temp - fdtsize, 2 * MiB); >
@Atish Patra may have some pointers about the 16MiB alignment requirement. Regards, Bin
