u-boot version: 2021.07-RC3 environment: Ubuntu 18.04 64-bit
[Description] Build and run u-boot:
make sandbox_defconfig make ./u-boot -d u-boot.dtb
Type the following on the command-line:
=> demo hello 5
I Got the following Error:
Command 'demo' failed: Error -22
If I disable CONFIG_OF_LIVE, the command will get the right answer.
[Analysis] Index 5 is the device named 'hexagon' defined in arch/sandbox/dts/sandbox.dtsi:
hexagon { compatible = "demo-simple"; colour = "white"; sides = <6>; };
device_probe will call of_to_plat, which finally call demo_parse_dt in drivers/demo/demo-uclass.c.
int demo_parse_dt(struct udevice *dev) { struct dm_demo_pdata *pdata = dev_get_plat(dev); int dn = dev_of_offset(dev);
pdata->sides = fdtdec_get_int(gd->fdt_blob, dn, "sides", 0); pdata->colour = fdt_getprop(gd->fdt_blob, dn, "colour", NULL); if (!pdata->sides || !pdata->colour) { debug("%s: Invalid device tree data\n", __func__); return -EINVAL; }
return 0; }
With the default configurations, I got 0 for pdata->sides, and NULL for pdata->colour. Seem that fdtdec_get_int and fdt_getprop hadn't get the correct values from device tree. With CONFIG_OF_LIVE enabled, node_ member of struct udevice will be set as a node pointer instead of an offset. dn = dev_of_offset(dev) will get an incorrect result, so "sides" and "colour" cannot be reached.
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Hongzhu Wang
bj_wanghz@126.com