4 ms·
I see that the PR against the Raspberry Pi linux repo is out [0]. Interestingly they are introducing a BCM2712 defconfig with a 64k default page size. From the
by bpye 3y ago
I see that the PR against the Raspberry Pi linux repo is out [0]. Interestingly they are introducing a BCM2712 defconfig with a 64k default page size.
From the device tree [1] it looks like they've rolled their own IOMMU rather than using ARM's SMMU which is annoying.
[0] - https://github.com/raspberrypi/linux/pull/5618 https://github.com/raspberrypi/linux/pull/5618
[1] - https://github.com/raspberrypi/linux/blob/9c75e5408c01cb7c6582200ce0f888c25d54626e/arch/arm/boot/dts/bcm2712.dtsi#L865C4-L894 https://github.com/raspberrypi/linux/blob/9c75e5408c01cb7c65...
- fanf2 3y agoInteresting. Did the earlier Raspberry Pi Broadcom SOCs not have an IOMMU? If they did I would have expected the 5 to be compatible with older ones.
- bpye 3y agoI'm fairly sure that none of the earlier SoCs had an IOMMU. It's of course possible that there was one hidden in the GPU or something, but nothing on the CPU side.
- proompter5 3y agoWhat would be the benefit of having their own IOMMU instead of just using the ARM SMMU?