From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Tue, 4 Apr 2017 00:07:07 +0200 Subject: [U-Boot] [PATCH 0/3] imx: bootaux elf firmware support In-Reply-To: <0d0cd2362362fb2029e46821678f2f8b@agner.ch> References: <20170329195827.6217-1-stefan@agner.ch> <20170403132024.514307fd@jawa> <0d0cd2362362fb2029e46821678f2f8b@agner.ch> Message-ID: <15002942-54e4-2271-f88e-fe67e9892f7d@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 04/03/2017 11:36 PM, Stefan Agner wrote: > Hi Lukasz, > > On 2017-04-03 04:20, Lukasz Majewski wrote: >> Hi Stefan, >> >> Thanks for your patch. Please allow me to share some ideas for >> improvements. >> >>> From: Stefan Agner >>> >>> This patchset enables to boot elf binaries on secondary Cortex-M >>> class cores available on i.MX 6SoloX/7Solo/7Dual. This makes >>> handling and loading firmwares much more convinient since all >>> information where the firmware has to be loaded to is contained in >>> the elf headers. A typical usage looks like this: >>> >>> Colibri iMX7 # tftp ${loadaddr} firmware.elf && bootaux ${loadaddr} >>> Using FEC0 device >>> TFTP from server 192.168.10.1; our IP address is 192.168.10.2 >>> Filename 'firmware.elf'. >>> Load address: 0x80800000 >>> Loading: ################################################## 88.3 >>> KiB 5.4 MiB/s >>> done >>> Bytes transferred = 90424 (16138 hex) >>> ## Starting auxiliary core at 0x1FFF8311 ... >>> Colibri iMX7 # >> >> I can find some other platforms (not only IMX), which would benefit >> from this code - the generic 'bootaux' command. >> >> One good example would to allow multiple binaries for different SoC >> Cores (e.g. 2x Cortex-A8) to be loaded and started by u-boot. >> >> Hence, I'm wondering if you could make those patches usable for other >> platforms as well? > > I don't think that this is a good idea. bootaux is meant for auxiliary > cores, which often use a different architecture and are not cache > coherent (hence the cache flushes). > > On SMP systems the main operating system normally starts the secondary > core. Otherwise, if you want to run them separately using U-Boot, maybe > a new command such as bootsmp would be more suited. > Admitedly, I didn't look at the patch, but if you want to boot ad-hoc cores, you can very well also boot secondary cores on the current CPU complex with the same command. Why not ? Also, I think this might come useful when booting stuff like "Altera Sparrow" ... -- Best regards, Marek Vasut