Hi Sughosh, On Sun, 13 Mar 2022 at 08:49, Sughosh Ganu <[email protected]> wrote: > > The 'rng' u-boot command is used for printing a select number of > random bytes on the console. Currently, the RNG device from which the > random bytes are read is fixed. However, a platform can have multiple > RNG devices, one example being qemu, which has a virtio RNG device and > the RNG pseudo device through the TPM chip. > > Extend the 'rng' command so that the user can provide the RNG device > number from which the random bytes are to be read. This will be the > device index under the RNG uclass. > > Signed-off-by: Sughosh Ganu <[email protected]> > Tested-by: Heinrich Schuchardt <[email protected]> > Reviewed-by: Ilias Apalodimas <[email protected]> > --- > > Changes since V4: > > * Use uclass_get_device_by_seq API to get the RNG device as suggested > by Simon > > cmd/rng.c | 31 +++++++++++++++++++++++-------- > 1 file changed, 23 insertions(+), 8 deletions(-)
Reviewed-by: Simon Glass <[email protected]> with the nit below fixed > > diff --git a/cmd/rng.c b/cmd/rng.c > index 1ad5a096c0..2ddf27545f 100644 > --- a/cmd/rng.c > +++ b/cmd/rng.c > @@ -13,19 +13,34 @@ > > static int do_rng(struct cmd_tbl *cmdtp, int flag, int argc, char *const > argv[]) > { > - size_t n = 0x40; > + size_t n; > struct udevice *dev; > void *buf; > + int devnum; > int ret = CMD_RET_SUCCESS; > > - if (uclass_get_device(UCLASS_RNG, 0, &dev) || !dev) { > + switch (argc) { > + case 1: > + devnum = 0; > + n = 0x40; > + break; > + case 2: > + devnum = hextoul(argv[1], NULL); > + n = 0x40; > + break; > + case 3: > + devnum = hextoul(argv[1], NULL); > + n = hextoul(argv[2], NULL); > + break; > + default: > + return CMD_RET_USAGE; > + } > + > + if (uclass_get_device_by_seq(UCLASS_RNG, devnum, &dev) || !dev) { Please check the function comments: you can drop the '|| !dev' bit since it returns an error if no device is found. > printf("No RNG device\n"); > return CMD_RET_FAILURE; > } > > - if (argc >= 2) > - n = hextoul(argv[1], NULL); > - > buf = malloc(n); > if (!buf) { > printf("Out of memory\n"); > @@ -46,12 +61,12 @@ static int do_rng(struct cmd_tbl *cmdtp, int flag, int > argc, char *const argv[]) > > #ifdef CONFIG_SYS_LONGHELP > static char rng_help_text[] = > - "[n]\n" > - " - print n random bytes\n"; > + "[dev [n]]\n" > + " - print n random bytes read from dev\n"; > #endif > > U_BOOT_CMD( > - rng, 2, 0, do_rng, > + rng, 3, 0, do_rng, > "print bytes from the hardware random number generator", > rng_help_text > ); > -- > 2.25.1 > Regards, SImon
