1 <h1>AArch64 UEFI bootstraps</h1> 2 3 <p>Copyright (c) 2011-2013 ARM Limited. All rights reserved. 4 See the <code>LICENSE.TXT</code> file for more information.</p> 5 6 <p>Contents:</p> 7 8 <ul> 9 <li>Introduction</li> 10 <li>Build</li> 11 <li>Use on ARMv8 RTSM and FVP models</li> 12 <li>Use on ARMv8 Foundation model</li> 13 </ul> 14 15 <h2>Introduction</h2> 16 17 <p>A bootstrap can be used to change the model state, like the Exception 18 Level (EL), before executing the UEFI binary.</p> 19 20 <p>For the ARMv8 RTSM and FVP models this can be used to show/test the UEFI binary 21 starting at different exception levels. The ARMv8 models start at EL3 by 22 default.</p> 23 24 <p>In the case of the Foundation model a bootstrap is required to jump to the 25 UEFI binary as loaded in RAM. This is required as the Foundation model cannot 26 load and execute UEFI binaries directly. The Foundation model can only load and 27 execute ELF binaries.</p> 28 29 <h2>Build</h2> 30 31 <p>Build the bootstraps using a AArch64 GCC cross-compiler. By default the 32 <code>Makefile</code> is configured to assume a GCC bare-metal toolchain:</p> 33 34 <pre><code>PATH=$PATH:<path/to/baremetal-tools/bin/> make clean 35 PATH=$PATH:<path/to/baremetal-tools/bin/> make 36 </code></pre> 37 38 <p>To build the bootstraps with a Linux GCC toolchain use the following 39 commands:</p> 40 41 <pre><code>PATH=$PATH:<path/to/aarch64-linux-gnu-tools/bin/> make clean 42 PATH=$PATH:<path/to/aarch64-linux-gnu-tools/bin/> CROSS_COMPILE=<gcc-prefix> make 43 </code></pre> 44 45 <p>The <code>gcc-prefix</code> depends on the specific toolchain distribution used. It can be 46 "aarch64-linux-gnu-" for example.</p> 47 48 <p>This will result in four <code>axf</code> files:</p> 49 50 <ul> 51 <li><p>uefi-bootstrap-el3 : The bootstrap jumps to the UEFI code in FLASH without 52 changing anything.</p></li> 53 <li><p>uefi-bootstrap-el2 : Setup EL3 and switch the model to EL2 before jumping to the 54 UEFI code in FLASH.</p></li> 55 <li><p>uefi-bootstrap-el1 : Setup EL3 and prepare to run at non-secure EL1. Switch to 56 non-secure EL1 and run the UEFI code in FLASH.</p></li> 57 <li><p>uefi-bootstrap-el3-foundation : The bootstrap jumps to the UEFI code in RAM 58 without changing anything. Only to be used with the 59 Foundation model. The Foundation model does not have 60 non-secure memory at address <code>0x0</code> and thus the UEFI image 61 should be pre-loaded into non-secure RAM at address 62 <code>0xA0000000</code>.</p></li> 63 </ul> 64 65 <h2>Use on ARMv8 RTSM and FVP models</h2> 66 67 <p>Add the '-a' option to the model start script and point to the required 68 bootstrap:</p> 69 70 <pre><code>< ... model start script as described in top-level readme file ... > 71 -a <path/to/bootstrap-binary-file> 72 </code></pre> 73 74 <p>NOTE: The Foundation model bootstrap should not be used with these models.</p> 75 76 <h2>Use on ARMv8 Foundation model</h2> 77 78 <p>The Foundation model takes an option for an ELF file to be loaded as well as an 79 option to load a binary data blob into RAM. This can be used to run UEFI in the 80 following manner:</p> 81 82 <pre><code><PATH_TO_INSTALLED_FOUNDATION_MODEL>/Foundation_v8 --cores=2 --visualization 83 --image=uefi-bootstrap-el3-foundation.axf --nsdata=RTSM_VE_FOUNDATIONV8_EFI.fd@0xA0000000 84 </code></pre> 85 86 <p>NOTE: The RTSM version of the bootstraps and UEFI image will not work as 87 expected on the Foundation model. Foundation model specific versions 88 should be used.</p> 89
