On 10/15/25 08:21, Jamin Lin wrote:
AST2700 has a 128KB SRAM, physically mapped at 0x10000000–0x1001FFFF for
the PSP (CA35) processor. The SSP coprocessor shares this same SRAM but
accesses it through a different address window at 0x70000000–0x7001FFFF.
To model this shared-memory behavior in QEMU, this commit introduces a
linked SRAM property and alias mapping between the PSP and SSP subsystems.
Changes include:
- Add a "MemoryRegion *sram" link and "MemoryRegion sram_alias" to
AspeedCoprocessorState.
- Register the new "sram" property in aspeed_coprocessor_common.c.
- In aspeed_ast27x0-fc.c, connect the SSP coprocessor’s "sram" link to
the PSP’s SRAM region.
- In aspeed_ast27x0-ssp.c, create an alias mapping for SRAM at
0x70000000 – 0x7001FFFF in the SSP’s memory map.
This ensures that the SSP can correctly access the shared SRAM contents
through its own address space while maintaining a consistent physical
backing region. It also guarantees that the SRAM is realized before the
SSP device, ensuring successful alias setup.
Signed-off-by: Jamin Lin <[email protected]>
---
include/hw/arm/aspeed_coprocessor.h | 3 ++-
hw/arm/aspeed_ast27x0-fc.c | 4 ++++
hw/arm/aspeed_ast27x0-ssp.c | 7 +++++++
hw/arm/aspeed_coprocessor_common.c | 2 ++
4 files changed, 15 insertions(+), 1 deletion(-)
Reviewed-by: Cédric Le Goater <[email protected]>
Thanks,
C.
