| Message ID | 20250205071714.635518-3-ilias.apalodimas@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | Fix page permission on arm64 architectures | expand |
On Wed, Feb 05, 2025 at 09:16:46AM +0200, Ilias Apalodimas wrote: > Since we added support in meminfo to dump live page tables, describe > the only working architecture for now (aarch64) and add links to public > documentation for further reading. > > Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Generally looks good, a small change however please: [snip] > @@ -26,8 +27,9 @@ The layout of memory is set up before relocation, within the init sequence in > ending with the stack. This results in the maximum possible amount of memory > being left free for image-loading. > > -The meminfo command writes the DRAM size, then the rest of its outputs in 5 > -columns: > +The meminfo command writes the DRAM size. If the architecture supports it > +(currently only aarch64) dumps the page table entries and then the rest of > +its outputs in 5 columns: How about: If the architecture also supports it, page table entries will be shown next. Finally the rest of the outputs are printed in 5 columns: This will make sure that when the next architecture adds support the documentation doesn't need to be updated here (and the temptation to list every arch that does this will be resisted). Thanks!
Hi Tom, On Wed, 5 Feb 2025 at 19:22, Tom Rini <trini@konsulko.com> wrote: > > On Wed, Feb 05, 2025 at 09:16:46AM +0200, Ilias Apalodimas wrote: > > > Since we added support in meminfo to dump live page tables, describe > > the only working architecture for now (aarch64) and add links to public > > documentation for further reading. > > > > Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> > > Generally looks good, a small change however please: > > [snip] > > @@ -26,8 +27,9 @@ The layout of memory is set up before relocation, within the init sequence in > > ending with the stack. This results in the maximum possible amount of memory > > being left free for image-loading. > > > > -The meminfo command writes the DRAM size, then the rest of its outputs in 5 > > -columns: > > +The meminfo command writes the DRAM size. If the architecture supports it > > +(currently only aarch64) dumps the page table entries and then the rest of > > +its outputs in 5 columns: > > How about: > If the architecture also supports it, page table entries will be shown > next. Finally the rest of the outputs are printed in 5 columns: > > This will make sure that when the next architecture adds support the > documentation doesn't need to be updated here (and the temptation to > list every arch that does this will be resisted). Thanks! Sure, this makes sense. Thanks /Ilias > > -- > Tom
Hi Ilias, On Wed, 5 Feb 2025 at 00:17, Ilias Apalodimas <ilias.apalodimas@linaro.org> wrote: > > Since we added support in meminfo to dump live page tables, describe > the only working architecture for now (aarch64) and add links to public > documentation for further reading. > > Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> > --- > doc/usage/cmd/meminfo.rst | 71 +++++++++++++++++++++++++++++---------- > 1 file changed, 53 insertions(+), 18 deletions(-) This is useless information for most people. I would rather have it behind a flag. Regards, Simon
Hi Simon On Thu, 6 Feb 2025 at 14:31, Simon Glass <sjg@chromium.org> wrote: > > Hi Ilias, > > On Wed, 5 Feb 2025 at 00:17, Ilias Apalodimas > <ilias.apalodimas@linaro.org> wrote: > > > > Since we added support in meminfo to dump live page tables, describe > > the only working architecture for now (aarch64) and add links to public > > documentation for further reading. > > > > Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> > > --- > > doc/usage/cmd/meminfo.rst | 71 +++++++++++++++++++++++++++++---------- > > 1 file changed, 53 insertions(+), 18 deletions(-) > > This is useless information for most people. I would rather have it > behind a flag. > Ok I can move the call a few lines below CONFIG_CMD_MEMINFO_MAP Thanks /Ilias > Regards, > Simon
diff --git a/doc/usage/cmd/meminfo.rst b/doc/usage/cmd/meminfo.rst index 6c94493cccc6..cf123f653059 100644 --- a/doc/usage/cmd/meminfo.rst +++ b/doc/usage/cmd/meminfo.rst @@ -18,7 +18,8 @@ Description The meminfo command shows the amount of memory. If ``CONFIG_CMD_MEMINFO_MAP`` is enabled, then it also shows the layout of memory used by U-Boot and the region -which is free for use by images. +which is free for use by images. In architectures that support it, it also prints +the mapped pages and their permissions. The latter is architecture specific. The layout of memory is set up before relocation, within the init sequence in ``board_init_f()``, specifically the various ``reserve_...()`` functions. This @@ -26,8 +27,9 @@ The layout of memory is set up before relocation, within the init sequence in ending with the stack. This results in the maximum possible amount of memory being left free for image-loading. -The meminfo command writes the DRAM size, then the rest of its outputs in 5 -columns: +The meminfo command writes the DRAM size. If the architecture supports it +(currently only aarch64) dumps the page table entries and then the rest of +its outputs in 5 columns: Region Name of the region @@ -99,28 +101,61 @@ free Free memory, which is available for loading images. The base address of this is ``gd->ram_base`` which is generally set by ``CFG_SYS_SDRAM_BASE``. +Aarch64 specific flags +---------------------- + +More information on the output can be found +Chapter D8 - The AArch64 Virtual Memory System Architecture at +https://developer.arm.com/documentation/ddi0487/latest/ + +In short, for a stage 1 translation regime the following apply: + +* RWX: Pages mapped with Read, Write and Execute permissions +* RO: Pages mapped with Read-Only permissions +* PXN: PXN (Privileged Execute Never) applies to execution at EL1 and above +* UXN: UXN (Unprivileged Execute Never) applies to EL0 + Example ------- This example shows output with both ``CONFIG_CMD_MEMINFO`` and -``CONFIG_CMD_MEMINFO_MAP`` enabled:: - - => meminfo - DRAM: 256 MiB +``CONFIG_CMD_MEMINFO_MAP`` enabled for aarch64 qemu:: + + DRAM: 8 GiB + Walking pagetable at 000000023ffe0000, va_bits: 40. Using 4 levels + [0x0000023ffe1000] | Table | | | + [0x0000023ffe2000] | Table | | | + [0x00000000000000 - 0x00000008000000] | Block | RWX | Normal | Inner-shareable + [0x00000008000000 - 0x00000040000000] | Block | PXN UXN | Device-nGnRnE | Non-shareable + [0x00000040000000 - 0x00000200000000] | Block | RWX | Normal | Inner-shareable + [0x0000023ffea000] | Table | | | + [0x00000200000000 - 0x0000023f600000] | Block | RWX | Normal | Inner-shareable + [0x0000023ffeb000] | Table | | | + [0x0000023f600000 - 0x0000023f68c000] | Pages | RWX | Normal | Inner-shareable + [0x0000023f68c000 - 0x0000023f74f000] | Pages | RO | Normal | Inner-shareable + [0x0000023f74f000 - 0x0000023f794000] | Pages | PXN UXN RO | Normal | Inner-shareable + [0x0000023f794000 - 0x0000023f79d000] | Pages | PXN UXN | Normal | Inner-shareable + [0x0000023f79d000 - 0x0000023f800000] | Pages | RWX | Normal | Inner-shareable + [0x0000023f800000 - 0x00000240000000] | Block | RWX | Normal | Inner-shareable + [0x00000240000000 - 0x00004000000000] | Block | RWX | Normal | Inner-shareable + [0x0000023ffe3000] | Table | | | + [0x00004010000000 - 0x00004020000000] | Block | PXN UXN | Device-nGnRnE | Non-shareable + [0x0000023ffe4000] | Table | | | + [0x00008000000000 - 0x00010000000000] | Block | PXN UXN | Device-nGnRnE | Non-shareable Region Base Size End Gap ------------------------------------------------ - video f000000 1000000 10000000 - code ec3a000 3c5d28 efffd28 2d8 - malloc 8c38000 6002000 ec3a000 0 - board_info 8c37f90 68 8c37ff8 8 - global_data 8c37d80 208 8c37f88 8 - devicetree 8c33000 4d7d 8c37d7d 3 - bootstage 8c32c20 3c8 8c32fe8 18 - bloblist 8c32000 400 8c32400 820 - stack 7c31ff0 1000000 8c31ff0 10 - free 0 7c31ff0 7c31ff0 0 - + video 23f7e0000 800000 23ffe0000 + code 23f68a000 156000 23f7e0000 0 + malloc 23e64a000 1040000 23f68a000 0 + board_info 23e649f80 78 23e649ff8 8 + global_data 23e649df0 188 23e649f78 8 + devicetree 23e549df0 100000 23e649df0 0 + bloblist 23e547000 2000 23e549000 df0 + stack 23d546ff0 1000000 23e546ff0 10 + lmb 23d546ff0 0 23d546ff0 0 + lmb 23d543000 3ff0 23d546ff0 0 + free 40000000 23d543000 27d543000 ffffffffc0000000 Return value ------------
Since we added support in meminfo to dump live page tables, describe the only working architecture for now (aarch64) and add links to public documentation for further reading. Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> --- doc/usage/cmd/meminfo.rst | 71 +++++++++++++++++++++++++++++---------- 1 file changed, 53 insertions(+), 18 deletions(-)