From: Leif Lindholm <leif.lindholm@linaro.org>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, patches@linaro.org,
hpa@linux.intel.com, tglx@linutronix.de, matt.fleming@intel.com,
Leif Lindholm <leif.lindholm@linaro.org>
Subject: [PATCH 1/4] Documentation: arm: [U]EFI runtime services
Date: Tue, 25 Jun 2013 19:11:00 +0100 [thread overview]
Message-ID: <1372183863-11333-2-git-send-email-leif.lindholm@linaro.org> (raw)
In-Reply-To: <1372183863-11333-1-git-send-email-leif.lindholm@linaro.org>
This patch provides documentation of the [U]EFI runtime services and
configuration features.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
---
Documentation/arm/00-INDEX | 3 +++
Documentation/arm/uefi.txt | 39 +++++++++++++++++++++++++++++++++++++++
2 files changed, 42 insertions(+)
create mode 100644 Documentation/arm/uefi.txt
diff --git a/Documentation/arm/00-INDEX b/Documentation/arm/00-INDEX
index 4978456..87e01d1 100644
--- a/Documentation/arm/00-INDEX
+++ b/Documentation/arm/00-INDEX
@@ -36,3 +36,6 @@ nwfpe/
- NWFPE floating point emulator documentation
swp_emulation
- SWP/SWPB emulation handler/logging description
+
+uefi.txt
+ - [U]EFI configuration and runtime services documentation
diff --git a/Documentation/arm/uefi.txt b/Documentation/arm/uefi.txt
new file mode 100644
index 0000000..5c48271
--- /dev/null
+++ b/Documentation/arm/uefi.txt
@@ -0,0 +1,39 @@
+The nomenclature EFI and UEFI are used interchangeably in this document.
+
+The implementation depends on receiving pointers to the UEFI memory map
+and System Table in a Flattened Device Tree - so is only available with
+CONFIG_OF.
+
+It (early) parses the FDT for the following parameters:
+- 'efi-system-table':
+ Physical address of the system table. (required)
+- 'efi-runtime-mmap':
+ Physical address of an EFI memory map, containing at least
+ the regions to be preserved. (required)
+- 'efi-runtime-mmap-size':
+ Size in bytes of the provided memory map. (required)
+- 'efi-mmap-desc-size':
+ Size of each descriptor in the memory map. (override default)
+- 'efi-mmap-desc-ver':
+ Memory descriptor format version. (override default)
+
+Since UEFI firmware on ARM systems are required to use a 1:1 memory map
+even on LPAE-capable systems, the above fields are 32-bit regardless.
+
+It also depends on early_ioremap to parse the memory map and preserve
+the regions required for runtime services.
+
+For actually enabling [U]EFI support, enable:
+- CONFIG_EFI=y
+- CONFIG_EFI_VARS=y or m
+
+After the kernel has mapped the required regions into its address space,
+a SetVirtualAddressMap() call is made into UEFI in order to update
+relocations. This call must be performed with all the code in a 1:1
+mapping. This implementation achieves this by temporarily disabling the
+MMU for the duration of this call. This can only be done safely:
+- before secondary CPUs are brought online.
+- after early_initcalls have completed, sinze it uses setup_mm_for_reboot().
+
+For verbose debug messages, specify 'uefi_debug' on the kernel command
+line.
--
1.7.10.4
next prev parent reply other threads:[~2013-06-25 18:06 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-25 18:10 [PATCH 0/4] arm: [U]EFI runtime services support Leif Lindholm
2013-06-25 18:11 ` Leif Lindholm [this message]
2013-06-25 18:46 ` [PATCH 1/4] Documentation: arm: [U]EFI runtime services Christopher Covington
2013-06-25 23:42 ` Stephen Warren
2013-06-26 13:20 ` Grant Likely
2013-06-26 13:53 ` Leif Lindholm
2013-06-26 13:59 ` Matt Fleming
2013-06-26 14:38 ` James Bottomley
2013-06-27 1:32 ` Matthew Garrett
2013-06-27 6:23 ` Grant Likely
2013-06-27 6:33 ` James Bottomley
2013-06-27 14:37 ` Matthew Garrett
2013-06-27 15:09 ` James Bottomley
2013-06-27 15:37 ` Grant Likely
2013-06-27 17:28 ` Matthew Garrett
2013-06-27 14:54 ` Grant Likely
2013-06-27 15:04 ` James Bottomley
2013-06-27 18:32 ` Russell King - ARM Linux
2013-06-27 9:00 ` Leif Lindholm
2013-06-27 14:38 ` Matthew Garrett
2013-06-27 18:32 ` H. Peter Anvin
2013-06-26 18:32 ` Stephen Warren
2013-06-26 19:31 ` Leif Lindholm
2013-06-27 18:04 ` Stephen Warren
2013-06-27 20:11 ` Grant Likely
2013-06-26 13:13 ` Grant Likely
2013-06-26 14:04 ` Leif Lindholm
2013-06-26 14:35 ` Grant Likely
2013-06-27 14:22 ` Arnd Bergmann
2013-06-30 3:21 ` Rob Landley
2013-06-25 18:11 ` [PATCH 2/4] x86: efi: break efi_lookup_mapped_addr out to generic code Leif Lindholm
2013-06-26 13:30 ` Grant Likely
2013-06-26 13:32 ` Matt Fleming
2013-06-26 14:11 ` Leif Lindholm
2013-06-26 14:40 ` Matt Fleming
2013-06-25 18:11 ` [PATCH 3/4] arm: Add [U]EFI runtime services support Leif Lindholm
2013-06-25 18:20 ` Matthew Garrett
2013-06-26 13:46 ` Grant Likely
2013-06-26 13:46 ` Grant Likely
2013-06-26 13:54 ` Matt Fleming
2013-06-26 14:15 ` Borislav Petkov
2013-06-26 14:35 ` Grant Likely
2013-06-26 14:22 ` Leif Lindholm
2013-06-25 18:11 ` [PATCH 4/4] init: efi: arm: enable (U)EFI runtime services on arm Leif Lindholm
2013-06-26 13:24 ` Grant Likely
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