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authorSimon Glass <sjg@chromium.org>2023-07-16 06:38:45 +0300
committerBin Meng <bmeng@tinylab.org>2023-07-17 12:08:44 +0300
commit297184143ab788b7e591604475760c1794532c99 (patch)
treef95d57491f28b0785cc9abb92ecf8b7458f7cd77 /doc
parent78f24d8f3415a9ceec993231b81efaa30e2a3cdc (diff)
downloadu-boot-297184143ab788b7e591604475760c1794532c99.tar.xz
acpi: Add a comment to set the acpi tables
Sometimes a previous bootloader has written ACPI tables. It is useful to be able to find and list these. Add an 'acpi set' command to set the address for these tables. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Diffstat (limited to 'doc')
-rw-r--r--doc/usage/cmd/acpi.rst29
1 files changed, 27 insertions, 2 deletions
diff --git a/doc/usage/cmd/acpi.rst b/doc/usage/cmd/acpi.rst
index 14bafc8e35..6b9b8949f3 100644
--- a/doc/usage/cmd/acpi.rst
+++ b/doc/usage/cmd/acpi.rst
@@ -11,12 +11,14 @@ Synopis
acpi list
acpi items [-d]
acpi dump <name>
+ acpi set <address>
Description
-----------
-The *acpi* command is used to dump the ACPI tables generated by U-Boot for passing
-to the operating systems.
+The *acpi* command is used to dump the ACPI tables generated by U-Boot for
+passing to the operating systems. It allows manually setting the address to take
+a look at existing ACPI tables.
ACPI tables can be generated by various output functions and even devices can
output material to include in the Differentiated System Description Table (DSDT)
@@ -231,5 +233,28 @@ Example
00000000: 44 53 44 54 ea 32 00 00 02 eb 55 2d 42 4f 4f 54 DSDT.2....U-BOOT
00000010: 55 2d 42 4f 4f 54 42 4c 25 07 11 20 49 4e 54 4c U-BOOTBL%.. INTL
+This shows searching for tables in a known area of memory, then setting the
+pointer::
+
+ => acpi list
+ No ACPI tables present
+ => ms.s bff00000 80000 "RSD PTR"
+ bff75000: 52 53 44 20 50 54 52 20 cf 42 4f 43 48 53 20 00 RSD PTR .BOCHS .
+ 1 match
+ => acpi set bff75000
+ Setting ACPI pointer to bff75000
+ => acpi list
+ Name Base Size Detail
+ ---- -------- ----- ------
+ RSDP bff75000 0 v00 BOCHS
+ RSDT bff76a63 38 v01 BOCHS BXPC 1 BXPC 1
+ FACP bff768ff 74 v01 BOCHS BXPC 1 BXPC 1
+ DSDT bff75080 187f v01 BOCHS BXPC 1 BXPC 1
+ FACS bff75040 40
+ APIC bff76973 90 v01 BOCHS BXPC 1 BXPC 1
+ HPET bff76a03 38 v01 BOCHS BXPC 1 BXPC 1
+ WAET bff76a3b 28 v01 BOCHS BXPC 1 BXPC 1
+ SSDT bff95040 c5 v02 COREv4 COREBOOT 2a CORE 20221020
+
.. _`ACPI specification`: https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf