| Message ID | cover.f8d15c19daa14158145260d790deac55f3c66fb3.1511864667.git-series.maxime.ripard@free-electrons.com |
|---|---|
| Headers | show |
| Series | env: Multiple env support and env transition for sunxi | expand |
On Tue, Nov 28, 2017 at 11:24:35AM +0100, Maxime Ripard wrote: > Hi, > > Here is an attempt at transitioning away from the MMC raw environment to a > FAT-based one. Since the RFC was quite well received, I actually tested it > and fixed a few rough edges. > > You'll find the first RFC here for reference: > https://lists.denx.de/pipermail/u-boot/2017-October/310111.html > > And the second that originated in this series: > https://lists.denx.de/pipermail/u-boot/2017-November/311608.html > > The fundamental issue I'm trying to adress is that we've had for a > very long time the assumption that the main U-Boot binary wouldn't > exceed around 500 bytes. > > However, we're starting to get real close to that limit, and are > running out of silver bullets to deal with the consequences of having > a bigger U-Boot binary, the main consequence being that we would > have some overlap between the environment and U-Boot. > > One way to address this that has been suggested by Tom is to move away > from the raw MMC environment to a FAT-based one. This would allow us > to slowly migrate away, and eventually remove the MMC-raw option > entirely to reclaim that space for the binary. > > That cannot be done in a single release however, since we might have > environments in the wild already that people rely on. And since we > always encouraged people to use the raw MMC environment, noone would > expect that. > > This is even worse since some platforms are using the U-Boot > environment to deal with implement their upgrade mechanism, such as > mender.io, and force moving the environment would break any further > upgrade. > > The suggested implementation is to allow U-Boot to compile multiple > environments backend at once, based on the work done by Simon. The > default behaviour shouldn't change obviously. We can then piggy-back > on this to tweak on a per-board basis the environment lookup algorithm > to always favour the FAT-based environment and then fallback to the > MMC. It will allow us to migrate a raw-MMC user to a FAT based > solution as soon as they update their environment (assuming that there > is a bootable FAT partition in the system). > > This has just been compile tested on sunxi so far, and I'd like > general comments on the approach taken. Obviously, this will need to > work properly before being merged. > > Let me know what you think, I think this is the right direction to head in. Can you please address the few outstanding points / questions and have something posted shortly after v2018.01 releases, and I'll apply it for inclusion in v2018.03? Thanks! -- Tom
Hi Tom, On Thu, Dec 07, 2017 at 03:09:31PM -0500, Tom Rini wrote: > > Here is an attempt at transitioning away from the MMC raw environment to a > > FAT-based one. Since the RFC was quite well received, I actually tested it > > and fixed a few rough edges. > > > > You'll find the first RFC here for reference: > > https://lists.denx.de/pipermail/u-boot/2017-October/310111.html > > > > And the second that originated in this series: > > https://lists.denx.de/pipermail/u-boot/2017-November/311608.html > > > > The fundamental issue I'm trying to adress is that we've had for a > > very long time the assumption that the main U-Boot binary wouldn't > > exceed around 500 bytes. > > > > However, we're starting to get real close to that limit, and are > > running out of silver bullets to deal with the consequences of having > > a bigger U-Boot binary, the main consequence being that we would > > have some overlap between the environment and U-Boot. > > > > One way to address this that has been suggested by Tom is to move away > > from the raw MMC environment to a FAT-based one. This would allow us > > to slowly migrate away, and eventually remove the MMC-raw option > > entirely to reclaim that space for the binary. > > > > That cannot be done in a single release however, since we might have > > environments in the wild already that people rely on. And since we > > always encouraged people to use the raw MMC environment, noone would > > expect that. > > > > This is even worse since some platforms are using the U-Boot > > environment to deal with implement their upgrade mechanism, such as > > mender.io, and force moving the environment would break any further > > upgrade. > > > > The suggested implementation is to allow U-Boot to compile multiple > > environments backend at once, based on the work done by Simon. The > > default behaviour shouldn't change obviously. We can then piggy-back > > on this to tweak on a per-board basis the environment lookup algorithm > > to always favour the FAT-based environment and then fallback to the > > MMC. It will allow us to migrate a raw-MMC user to a FAT based > > solution as soon as they update their environment (assuming that there > > is a bootable FAT partition in the system). > > > > This has just been compile tested on sunxi so far, and I'd like > > general comments on the approach taken. Obviously, this will need to > > work properly before being merged. > > > > Let me know what you think, > > I think this is the right direction to head in. Can you please address > the few outstanding points / questions This is done already. > and have something posted shortly after v2018.01 releases, and I'll > apply it for inclusion in v2018.03? And I was waiting for your feedback :) I'll do that, thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
Hi, Here is an attempt at transitioning away from the MMC raw environment to a FAT-based one. Since the RFC was quite well received, I actually tested it and fixed a few rough edges. You'll find the first RFC here for reference: https://lists.denx.de/pipermail/u-boot/2017-October/310111.html And the second that originated in this series: https://lists.denx.de/pipermail/u-boot/2017-November/311608.html The fundamental issue I'm trying to adress is that we've had for a very long time the assumption that the main U-Boot binary wouldn't exceed around 500 bytes. However, we're starting to get real close to that limit, and are running out of silver bullets to deal with the consequences of having a bigger U-Boot binary, the main consequence being that we would have some overlap between the environment and U-Boot. One way to address this that has been suggested by Tom is to move away from the raw MMC environment to a FAT-based one. This would allow us to slowly migrate away, and eventually remove the MMC-raw option entirely to reclaim that space for the binary. That cannot be done in a single release however, since we might have environments in the wild already that people rely on. And since we always encouraged people to use the raw MMC environment, noone would expect that. This is even worse since some platforms are using the U-Boot environment to deal with implement their upgrade mechanism, such as mender.io, and force moving the environment would break any further upgrade. The suggested implementation is to allow U-Boot to compile multiple environments backend at once, based on the work done by Simon. The default behaviour shouldn't change obviously. We can then piggy-back on this to tweak on a per-board basis the environment lookup algorithm to always favour the FAT-based environment and then fallback to the MMC. It will allow us to migrate a raw-MMC user to a FAT based solution as soon as they update their environment (assuming that there is a bootable FAT partition in the system). This has just been compile tested on sunxi so far, and I'd like general comments on the approach taken. Obviously, this will need to work properly before being merged. Let me know what you think, Maxime Changes from the RFC: - Added more useful messages to see where we're loading / saving - Init all the environments no matter what, and the deal with whatever env we want to pick at load time - Added the various tags collected Maxime Ripard (14): cmd: nvedit: Get rid of the env lookup env: Rename env_driver_lookup_default and env_get_default_location env: Pass additional parameters to the env lookup function env: Make the env save message a bit more explicit env: Make it explicit where we're loading our environment from env: fat: Make the debug messages play a little nicer env: mmc: Make the debug messages play a little nicer env: common: Make the debug messages play a little nicer env: Support multiple environments env: Initialise all the environments env: Allow to build multiple environments in Kconfig env: Mark env_get_location as weak sunxi: Transition from the MMC to a FAT-based environment env: sunxi: Enable FAT-based environment support by default board/sunxi/board.c | 16 +++- cmd/nvedit.c | 4 +- env/Kconfig | 69 +++++------ env/common.c | 2 +- env/env.c | 198 +++++++++++++++++++------------ env/fat.c | 9 +- env/mmc.c | 1 +- include/asm-generic/global_data.h | 1 +- include/environment.h | 14 +- 9 files changed, 192 insertions(+), 122 deletions(-) base-commit: c253573f3e269fd9a24ee6684d87dd91106018a5