Re: New fast(?)-boot results on ARM

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Robert Schwebel wrote:
On Fri, Aug 14, 2009 at 10:04:57PM +0200, Denys Vlasenko wrote:
rsc@thebe:~$ microcom | ptx_ts "U-Boot 2.0.0-rc9"
[  2.395740] <  2.395740>
[  2.395860] <  0.000120>
[  0.000011] <  0.000011> U-Boot 2.0.0-rc9 (Aug  5 2009 - 10:05:58)
[  0.000059] <  0.000048>
[  0.003823] <  0.003764> Board: Phytec phyCORE-i.MX27
[  0.010753] <  0.006930> cfi_probe: cfi_flash base: 0xc0000000 size: 0x02000000
[  0.018711] <  0.007958> NAND device: Manufacturer ID: 0x20, Chip ID: 0x36 (ST Micro NAND 64MiB 1,8V 8-bit)
[  0.026592] <  0.007881> imxfb@imxfb0: i.MX Framebuffer driver
[  0.178655] <  0.152063> dev_protect: currently broken
[  0.178736] <  0.000081> Using environment in NOR Flash
[  0.182577] <  0.003841> initialising PLLs
[  0.367142] <  0.184565> Malloc space: 0xa3f00000 -> 0xa7f00000 (size 64 MB)
[  0.370568] <  0.003426> Stack space : 0xa3ef8000 -> 0xa3f00000 (size 32 kB)
[  0.445993] <  0.075425> running /env/bin/init...
[  0.870592] <  0.424599>
[  0.874559] <  0.003967> Hit any key to stop autoboot:  0
boot loader is not fast. considering its simple task, it can be made
faster.

Yup, will check. Almost 1 s seems really long.

Some things to check regarding this and kernel uncompression (copy):

- How often is (compressed/uncompressed) kernel data copied? Once the compressed one from storage (NOR/NAND?) to RAM by boot loader? Then by kernel's uncompression from RAM to it's final location in RAM?

- For boot loader and uncompression, is D-Cache enabled?

- Is data (image) copy done by optimized functions? Using (a) DMA or at least (b) some optimized memcpy using ARM's ldmia/stmia?

Best regards

Dirk
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