The AST2500 SoC family changes the runtime behaviour of the hardware strapping register (SCU70) to write-1-set/write-1-clear, with write-1-clear implemented on the "read-only" SoC revision register (SCU7C). For the the AST2400, the hardware strapping is runtime-configured with read-modify-write semantics.
Signed-off-by: Andrew Jeffery <and...@aj.id.au> --- hw/misc/aspeed_scu.c | 19 +++++++++++++++++-- include/hw/misc/aspeed_scu.h | 2 ++ 2 files changed, 19 insertions(+), 2 deletions(-) diff --git a/hw/misc/aspeed_scu.c b/hw/misc/aspeed_scu.c index 5e6d5744eeca..9051767cbbcd 100644 --- a/hw/misc/aspeed_scu.c +++ b/hw/misc/aspeed_scu.c @@ -202,11 +202,26 @@ static void aspeed_scu_write(void *opaque, hwaddr offset, uint64_t data, case PROT_KEY: s->regs[reg] = (data == ASPEED_SCU_PROT_KEY) ? 1 : 0; return; - + case HW_STRAP1: + if (ASPEED_IS_AST2500(s->regs[SILICON_REV])) { + s->regs[HW_STRAP1] |= data; + return; + } + /* Jump to assignment below */ + break; + case SILICON_REV: + if (ASPEED_IS_AST2500(s->regs[SILICON_REV])) { + s->regs[HW_STRAP1] &= ~data; + } else { + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Write to read-only offset 0x%" HWADDR_PRIx "\n", + __func__, offset); + } + /* Avoid assignment below, we've handled everything */ + return; case FREQ_CNTR_EVAL: case VGA_SCRATCH1 ... VGA_SCRATCH8: case RNG_DATA: - case SILICON_REV: case FREE_CNTR4: case FREE_CNTR4_EXT: qemu_log_mask(LOG_GUEST_ERROR, diff --git a/include/hw/misc/aspeed_scu.h b/include/hw/misc/aspeed_scu.h index d70cc0aeca61..169611a211bb 100644 --- a/include/hw/misc/aspeed_scu.h +++ b/include/hw/misc/aspeed_scu.h @@ -37,6 +37,8 @@ typedef struct AspeedSCUState { #define AST2500_A0_SILICON_REV 0x04000303U #define AST2500_A1_SILICON_REV 0x04010303U +#define ASPEED_IS_AST2500(si_rev) ((((si_rev) >> 24) & 0xff) == 0x04) + extern bool is_supported_silicon_rev(uint32_t silicon_rev); #define ASPEED_SCU_PROT_KEY 0x1688A8A8 -- 2.17.1