| Message ID | 1439906635-28191-1-git-send-email-guillaume.gardet@free.fr |
|---|---|
| State | Changes Requested |
| Delegated to: | Tom Rini |
| Headers | show |
On 08/18/2015 08:03 AM, Guillaume GARDET wrote: > Add CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG support to set 'board_rev' and > 'board_name' envs. That states what the patch does rather than why its useful to do it. Can you expand on why it's useful to set these variables? > diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c > @@ -240,6 +240,12 @@ int misc_init_r(void) > { > set_fdtfile(); > set_usbethaddr(); > +#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG > + char str_rev[11]; > + sprintf(str_rev, "0x%X", rpi_board_rev); > + setenv("board_rev", str_rev); > + setenv("board_name", models[rpi_board_rev].name); > +#endif > return 0; > } That adds a variable declaration in the middle of code. I'd suggest moving the new code into set_board_info() (a name that some other boards/SoCs that honor CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG use), and calling that function inside the ifdef in misc_init_r(). You can always make the function static and implement it before misc_init_r() so that the compiler is likely to inline it. I'm not sure that models[rpi_board_rev].name contains values that are useful to place into an environment variable. It depends what you expect to do with that variable. Note that the values are not unique, and contain spaces, which might make the value hard to use and/or not reliable to differentiate between all the different types of boards. Conceptually I have no general objection to this patch, although I am a little worried about turning the board_name variable into some kind of ABI.
Le 19/08/2015 05:14, Stephen Warren a écrit : > On 08/18/2015 08:03 AM, Guillaume GARDET wrote: >> Add CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG support to set 'board_rev' and >> 'board_name' envs. > That states what the patch does rather than why its useful to do it. Can > you expand on why it's useful to set these variables? Using boot scripts you may need to get the board version / revision infos, for example to select the right DTB since u-boot DTB names and kernel DTB files do not match. > >> diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c >> @@ -240,6 +240,12 @@ int misc_init_r(void) >> { >> set_fdtfile(); >> set_usbethaddr(); >> +#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG >> + char str_rev[11]; >> + sprintf(str_rev, "0x%X", rpi_board_rev); >> + setenv("board_rev", str_rev); >> + setenv("board_name", models[rpi_board_rev].name); >> +#endif >> return 0; >> } > That adds a variable declaration in the middle of code. I'd suggest > moving the new code into set_board_info() (a name that some other > boards/SoCs that honor CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG use), and > calling that function inside the ifdef in misc_init_r(). You can always > make the function static and implement it before misc_init_r() so that > the compiler is likely to inline it. Ok, will do that. > > I'm not sure that models[rpi_board_rev].name contains values that are > useful to place into an environment variable. It depends what you expect > to do with that variable. Note that the values are not unique, and > contain spaces, which might make the value hard to use and/or not > reliable to differentiate between all the different types of boards. > > Conceptually I have no general objection to this patch, although I am a > little worried about turning the board_name variable into some kind of ABI. > board_name variable should be considered to get a pretty board info print, not any kind of ABI. If people need to differentiate boards revs, just use board_rev variable. Guillaume
On 08/21/2015 03:47 AM, Guillaume Gardet wrote: > > > Le 19/08/2015 05:14, Stephen Warren a écrit : >> On 08/18/2015 08:03 AM, Guillaume GARDET wrote: >>> Add CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG support to set 'board_rev' and >>> 'board_name' envs. >> That states what the patch does rather than why its useful to do it. Can >> you expand on why it's useful to set these variables? > > Using boot scripts you may need to get the board version / revision > infos, for example to select the right DTB since u-boot DTB names and > kernel DTB files do not match. The fix here isn't to craft all kinds of complex scripts in U-Boot based on a slew of extra variables. Rather, the set of DT files in the kernel should be expanded so that there is one DT per board design, i.e. so the filenames in the kernel match the filenames that U-Boot expects. >>> diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c >>> @@ -240,6 +240,12 @@ int misc_init_r(void) >>> { >>> set_fdtfile(); >>> set_usbethaddr(); >>> +#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG >>> + char str_rev[11]; >>> + sprintf(str_rev, "0x%X", rpi_board_rev); >>> + setenv("board_rev", str_rev); >>> + setenv("board_name", models[rpi_board_rev].name); >>> +#endif >>> return 0; >>> } >> >> That adds a variable declaration in the middle of code. I'd suggest >> moving the new code into set_board_info() (a name that some other >> boards/SoCs that honor CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG use), and >> calling that function inside the ifdef in misc_init_r(). You can always >> make the function static and implement it before misc_init_r() so that >> the compiler is likely to inline it. > > Ok, will do that. > >> >> I'm not sure that models[rpi_board_rev].name contains values that are >> useful to place into an environment variable. It depends what you expect >> to do with that variable. Note that the values are not unique, and >> contain spaces, which might make the value hard to use and/or not >> reliable to differentiate between all the different types of boards. >> >> Conceptually I have no general objection to this patch, although I am a >> little worried about turning the board_name variable into some kind of >> ABI. > > board_name variable should be considered to get a pretty board info > print, not any kind of ABI. If people need to differentiate boards revs, > just use board_rev variable. The values in models[] are already printed when U-Boot starts. If those are the only justifications for this patch, I'm not sure it's a good idea.
On Tue, 2015-08-25 at 19:34 -0600, Stephen Warren wrote: > On 08/21/2015 03:47 AM, Guillaume Gardet wrote: > > > > > > Le 19/08/2015 05:14, Stephen Warren a écrit : > >> On 08/18/2015 08:03 AM, Guillaume GARDET wrote: > >>> Add CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG support to set 'board_rev' and > >>> 'board_name' envs. > >> That states what the patch does rather than why its useful to do it. Can > >> you expand on why it's useful to set these variables? > > > > Using boot scripts you may need to get the board version / revision > > infos, for example to select the right DTB since u-boot DTB names and > > kernel DTB files do not match. > > The fix here isn't to craft all kinds of complex scripts in U-Boot based > on a slew of extra variables. Rather, the set of DT files in the kernel > should be expanded so that there is one DT per board design, i.e. so the > filenames in the kernel match the filenames that U-Boot expects. > You speak of "the kernel" as if there were only one. FreeBSD also uses dtb files, and we often have to do local patches to u-boot source to make it emit identifying info such as soc type/model/rev and board rev so that we can choose the right dtb file. The way we handle dtb files is nothing like what linux does, but we use the same dts source and dtb files as linux. In some cases we need u-boot to load those files, in other cases we just need some u-boot script code to set fdt_file to the right name, then our next-stage kernel loader handles the actual loading of the file. Who does the loading isn't as important as being able to choose the right file to load, given an sdcard image that contains a single kernel that works for a variety of related boards, but multiple dtb files, one per board. -- Ian
On 08/25/2015 07:46 PM, Ian Lepore wrote: > On Tue, 2015-08-25 at 19:34 -0600, Stephen Warren wrote: >> On 08/21/2015 03:47 AM, Guillaume Gardet wrote: >>> >>> >>> Le 19/08/2015 05:14, Stephen Warren a écrit : >>>> On 08/18/2015 08:03 AM, Guillaume GARDET wrote: >>>>> Add CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG support to set 'board_rev' and >>>>> 'board_name' envs. >>>> That states what the patch does rather than why its useful to do it. Can >>>> you expand on why it's useful to set these variables? >>> >>> Using boot scripts you may need to get the board version / revision >>> infos, for example to select the right DTB since u-boot DTB names and >>> kernel DTB files do not match. >> >> The fix here isn't to craft all kinds of complex scripts in U-Boot based >> on a slew of extra variables. Rather, the set of DT files in the kernel >> should be expanded so that there is one DT per board design, i.e. so the >> filenames in the kernel match the filenames that U-Boot expects. > > You speak of "the kernel" as if there were only one. You're right; I should have said "DT file repository" not "kernel" here. In practice, that's the Linux kernel at present though. Still, I stand by my assertion that the values U-Boot expects for DTB filenames make sense, and we should update any/all repositories of DTB files so there is a complete set of matching files.
diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c index d21750e..b61ff67 100644 --- a/board/raspberrypi/rpi/rpi.c +++ b/board/raspberrypi/rpi/rpi.c @@ -240,6 +240,12 @@ int misc_init_r(void) { set_fdtfile(); set_usbethaddr(); +#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG + char str_rev[11]; + sprintf(str_rev, "0x%X", rpi_board_rev); + setenv("board_rev", str_rev); + setenv("board_name", models[rpi_board_rev].name); +#endif return 0; } diff --git a/include/configs/rpi-common.h b/include/configs/rpi-common.h index 8830a10..17237cf 100644 --- a/include/configs/rpi-common.h +++ b/include/configs/rpi-common.h @@ -133,6 +133,7 @@ #include <config_distro_defaults.h> /* Environment */ +#define CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG #define ENV_DEVICE_SETTINGS \ "stdin=serial,lcd\0" \ "stdout=serial,lcd\0" \
Add CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG support to set 'board_rev' and 'board_name' envs. Signed-off-by: Guillaume GARDET <guillaume.gardet@free.fr> Cc: Stephen Warren <swarren@wwwdotorg.org> --- board/raspberrypi/rpi/rpi.c | 6 ++++++ include/configs/rpi-common.h | 1 + 2 files changed, 7 insertions(+)