On 1/9/2026 10:16 AM, Joel Stanley wrote:
From: Nicholas Piggin <[email protected]>
Machines that have discontiguous memory may need to adjust where
firmware and images are loaded at boot. Provide an interfaces for
machines to describe a discontiguous low/high RAM scheme for this
purpose.
Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Joel Stanley <[email protected]>
---
Reviewed-by: Daniel Henrique Barboza <[email protected]>
include/hw/riscv/boot.h | 7 +++++++
hw/riscv/boot.c | 11 +++++++++++
2 files changed, 18 insertions(+)
diff --git a/include/hw/riscv/boot.h b/include/hw/riscv/boot.h
index f00b3ca12245..115e3222174f 100644
--- a/include/hw/riscv/boot.h
+++ b/include/hw/riscv/boot.h
@@ -28,6 +28,10 @@
#define RISCV64_BIOS_BIN "opensbi-riscv64-generic-fw_dynamic.bin"
typedef struct RISCVBootInfo {
+ /* First contiguous RAM region. If size is zero then assume entire RAM */
+ hwaddr ram_low_start;
+ hwaddr ram_low_size;
+
ssize_t kernel_size;
hwaddr image_low_addr;
hwaddr image_high_addr;
@@ -43,6 +47,9 @@ bool riscv_is_32bit(RISCVHartArrayState *harts);
char *riscv_plic_hart_config_string(int hart_count);
void riscv_boot_info_init(RISCVBootInfo *info, RISCVHartArrayState *harts);
+void riscv_boot_info_init_discontig_mem(RISCVBootInfo *info,
+ RISCVHartArrayState *harts,
+ hwaddr start, hwaddr size);
vaddr riscv_calc_kernel_start_addr(RISCVBootInfo *info,
hwaddr firmware_end_addr);
hwaddr riscv_find_and_load_firmware(MachineState *machine,
diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
index e5490beda007..9babb85b0458 100644
--- a/hw/riscv/boot.c
+++ b/hw/riscv/boot.c
@@ -69,11 +69,22 @@ char *riscv_plic_hart_config_string(int hart_count)
void riscv_boot_info_init(RISCVBootInfo *info, RISCVHartArrayState *harts)
{
+ info->ram_low_start = 0;
+ info->ram_low_size = 0;
info->kernel_size = 0;
info->initrd_size = 0;
info->is_32bit = riscv_is_32bit(harts);
}
+void riscv_boot_info_init_discontig_mem(RISCVBootInfo *info,
+ RISCVHartArrayState *harts,
+ hwaddr start, hwaddr size)
+{
+ riscv_boot_info_init(info, harts);
+ info->ram_low_start = start;
+ info->ram_low_size = size;
+}
+
vaddr riscv_calc_kernel_start_addr(RISCVBootInfo *info,
hwaddr firmware_end_addr) {
if (info->is_32bit) {
