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Diffstat (limited to 'doc/README.chromium')
| -rw-r--r-- | doc/README.chromium | 41 |
1 files changed, 38 insertions, 3 deletions
diff --git a/doc/README.chromium b/doc/README.chromium index 8f67da6c728..75f2f24042c 100644 --- a/doc/README.chromium +++ b/doc/README.chromium @@ -23,6 +23,13 @@ available: from U-Boot in 2013) and coreboot. See below for more information on this. + - Running U-Boot from coreboot. This allows U-Boot to run on more devices + since many of them only support coreboot as the bootloader and have + no bare-metal support in U-Boot. For this, use the 'coreboot' target. + + - Running U-Boot and booting into a Chrome OS image, but without verified + boot. This can be useful for testing. + U-Boot with Chromium OS verified boot ------------------------------------- @@ -168,14 +175,42 @@ existed in U-Boot were not brought over to coreboot or depthcharge. The U-Boot tests ('make check') do operate, but at present there are no Chromium OS tests available. These will hopefully come together over time. Of course the above sandbox feature provides a sort of functional test and can -detecte problems that affect the flow or particular vboot features. +detect problems that affect the flow or particular vboot features. + + +U-Boot without Chromium OS verified boot +---------------------------------------- + +The following script can be used to boot a Chrome OS image on coral: + + # Read the image header and obtain the address of the kernel + # The offset 4f0 is defined by verified boot and may change for other + # Chromebooks + read mmc 2:2 100000 0 80; setexpr loader *001004f0; + + # Get the kernel size and calculate the number of blocks (0x200 bytes each) + setexpr size *00100518; setexpr blocks $size / 200; + + # Read the full kernel and calculate the address of the setup block + read mmc 2:2 100000 80 $blocks; setexpr setup $loader - 1000; + + # Locate the command line + setexpr cmdline $loader - 2000; + + # Start the zboot process with the loaded kernel, setup block and cmdline + zboot start 100000 0 0 0 $setup $cmdline; + + # Load the kernel, fix up the 'setup' block, dump information + zboot load; zboot setup; zboot dump + + # Boot into Chrome OS + zboot go TO DO ----- -- Support for booting from coreboot (patches expected March 2019) -- Support for booting from an ARM board, e.g. bob +Get the full ACPI tables working with Coral Simon Glass |