From: Jamin Lin <jamin_...@aspeedtech.com> On AST2700 SoC, QEMU now sets BIT6 in VGA0 SCRATCH register to indicate that DDR training has completed, thus skipping the dram_init().
To align with the recent U-Boot changes, where the Main Control Register's BIT16 is checked to skip the dram_init() process, this patch sets BIT16 in the SDMC Main Control Register at reset time. This allows both the main U-Boot stage to correctly detect and bypass DRAM initialization when running under QEMU. Reference: - QEMU: https://github.com/qemu/qemu/commit/2d082fea485ee455a70ed3e963cdf9a70f34858a - U-Boot: https://github.com/AspeedTech-BMC/u-boot/commit/94e5435504fb0d8888f5c1bfd3fa284cdd6aaf9b Signed-off-by: Jamin Lin <jamin_...@aspeedtech.com> Reviewed-by: Cédric Le Goater <c...@redhat.com> Link: https://lore.kernel.org/qemu-devel/20250618080006.846355-2-jamin_...@aspeedtech.com Signed-off-by: Cédric Le Goater <c...@redhat.com> --- hw/misc/aspeed_sdmc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/hw/misc/aspeed_sdmc.c b/hw/misc/aspeed_sdmc.c index f04d9930dd79..dff7cc362d32 100644 --- a/hw/misc/aspeed_sdmc.c +++ b/hw/misc/aspeed_sdmc.c @@ -570,6 +570,9 @@ static void aspeed_2700_sdmc_reset(DeviceState *dev) /* Set ram size bit and defaults values */ s->regs[R_MAIN_CONF] = asc->compute_conf(s, 0); + /* Skipping dram init */ + s->regs[R_MAIN_CONTROL] = BIT(16); + if (s->unlocked) { s->regs[R_2700_PROT] = PROT_UNLOCKED; } -- 2.50.0
