| Message ID | 20220228120638.678137-11-sughosh.ganu@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | tpm: rng: Move TPM RNG functionality to driver model | expand |
Hi Sughosh, On Mon, 28 Feb 2022 at 05:07, Sughosh Ganu <sughosh.ganu@linaro.org> 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 <sughosh.ganu@linaro.org> > Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > --- > > Changes since V1: > * Changed the help text to show order of the parameters passed > to the rng command, based on review comment from Heinrich > > cmd/rng.c | 31 +++++++++++++++++++++++-------- > 1 file changed, 23 insertions(+), 8 deletions(-) Please add a test for the command and also add doc/usage Regards, Simon
hi Simon, On Tue, 1 Mar 2022 at 20:29, Simon Glass <sjg@chromium.org> wrote: > > Hi Sughosh, > > On Mon, 28 Feb 2022 at 05:07, Sughosh Ganu <sughosh.ganu@linaro.org> 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 <sughosh.ganu@linaro.org> > > Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > > --- > > > > Changes since V1: > > * Changed the help text to show order of the parameters passed > > to the rng command, based on review comment from Heinrich > > > > cmd/rng.c | 31 +++++++++++++++++++++++-------- > > 1 file changed, 23 insertions(+), 8 deletions(-) > > Please add a test for the command and also add doc/usage We already have a test for the RNG uclass, which is basically doing the exact same thing. Do we still need one for the command? Or is it for testing the command parameters? -sughosh > > Regards, > Simon
Hi Sughosh, On Tue, 1 Mar 2022 at 21:56, Sughosh Ganu <sughosh.ganu@linaro.org> wrote: > > hi Simon, > > On Tue, 1 Mar 2022 at 20:29, Simon Glass <sjg@chromium.org> wrote: > > > > Hi Sughosh, > > > > On Mon, 28 Feb 2022 at 05:07, Sughosh Ganu <sughosh.ganu@linaro.org> 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 <sughosh.ganu@linaro.org> > > > Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > > > --- > > > > > > Changes since V1: > > > * Changed the help text to show order of the parameters passed > > > to the rng command, based on review comment from Heinrich > > > > > > cmd/rng.c | 31 +++++++++++++++++++++++-------- > > > 1 file changed, 23 insertions(+), 8 deletions(-) > > > > Please add a test for the command and also add doc/usage > > We already have a test for the RNG uclass, which is basically doing > the exact same thing. Do we still need one for the command? Or is it > for testing the command parameters? Yes and it provides test coverage. See acpi.c for an example test. It can be quite simple I suspect. Regards, Simon
diff --git a/cmd/rng.c b/cmd/rng.c index 1ad5a096c0..bb89cfa784 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(UCLASS_RNG, devnum, &dev) || !dev) { 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 );