From: Bin Meng <bin.m...@windriver.com> U-Boot expects PMU_MISC0 register bit 7 is set (see init_bandgap() in arch/arm/mach-imx/mx6/soc.c) during boot. This bit indicates the bandgap has stabilized.
With this change, the latest upstream U-Boot (v2021.01-rc3) for imx6 sabrelite board (mx6qsabrelite_defconfig), with a slight change made by switching CONFIG_OF_SEPARATE to CONFIG_OF_EMBED, boots to U-Boot shell on QEMU with the following command: $ qemu-system-arm -M sabrelite -smp 4 -m 1G -kernel u-boot \ -display none -serial null -serial stdio Boot log below: U-Boot 2021.01-rc3 (Dec 12 2020 - 17:40:02 +0800) CPU: Freescale i.MX?? rev1.0 at 792 MHz Reset cause: POR Model: Freescale i.MX6 Quad SABRE Lite Board Board: SABRE Lite I2C: ready DRAM: 1 GiB force_idle_bus: sda=0 scl=0 sda.gp=0x5c scl.gp=0x55 force_idle_bus: failed to clear bus, sda=0 scl=0 force_idle_bus: sda=0 scl=0 sda.gp=0x6d scl.gp=0x6c force_idle_bus: failed to clear bus, sda=0 scl=0 force_idle_bus: sda=0 scl=0 sda.gp=0xcb scl.gp=0x5 force_idle_bus: failed to clear bus, sda=0 scl=0 MMC: FSL_SDHC: 0, FSL_SDHC: 1 Loading Environment from MMC... *** Warning - No block device, using default environment In: serial Out: serial Err: serial Net: Board Net Initialization Failed No ethernet found. starting USB... Bus usb@2184000: usb dr_mode not found USB EHCI 1.00 Bus usb@2184200: USB EHCI 1.00 scanning bus usb@2184000 for devices... 1 USB Device(s) found scanning bus usb@2184200 for devices... 1 USB Device(s) found scanning usb for storage devices... 0 Storage Device(s) found scanning usb for ethernet devices... 0 Ethernet Device(s) found Hit any key to stop autoboot: 0 => Signed-off-by: Bin Meng <bin.m...@windriver.com> Reviewed-by: Alex Bennée <alex.ben...@linaro.org> --- (no changes since v1) hw/misc/imx6_ccm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/misc/imx6_ccm.c b/hw/misc/imx6_ccm.c index cb740427ec..7e031b6775 100644 --- a/hw/misc/imx6_ccm.c +++ b/hw/misc/imx6_ccm.c @@ -450,7 +450,7 @@ static void imx6_ccm_reset(DeviceState *dev) s->analog[PMU_REG_3P0] = 0x00000F74; s->analog[PMU_REG_2P5] = 0x00005071; s->analog[PMU_REG_CORE] = 0x00402010; - s->analog[PMU_MISC0] = 0x04000000; + s->analog[PMU_MISC0] = 0x04000080; s->analog[PMU_MISC1] = 0x00000000; s->analog[PMU_MISC2] = 0x00272727; -- 2.25.1