[haiku-bugs] [Haiku] #10663: RSDP and MP Floating Pointer scan spots
- From: yaniv@xxxxxxxxxxxxxx
- Date: Mon, 10 Mar 2014 11:35:31 -0000
#10663: RSDP and MP Floating Pointer scan spots
---------------------------+------------------------------
Reporter: yaniv | Owner: axeld
Type: bug | Status: new
Priority: normal | Milestone: R1
Component: System/Kernel | Version: R1/Development
Keywords: | Blocked By:
Blocking: | Has a Patch: 0
Platform: x86 |
---------------------------+------------------------------
'''In src/system/boot/platform/bios_ia32/acpi.cpp'''
acpi_scan_spots[] includes BDA area, it should be the first 1 KB of EBDA.
According to spec:
OSPM finds the Root System Description Pointer (RSDP) structure by
searching
physical memory ranges on 16-byte boundaries for a valid Root System
Description
Pointer structure signature and checksum match as follows:
• The first 1 KB of the Extended BIOS Data Area (EBDA). For EISA or MCA
systems,
the EBDA can be found in the two-byte location 40:0Eh on the BIOS data
area.
• The BIOS read-only memory space between 0E0000h and 0FFFFFh.
'''In src/system/boot/platform/bios_ia32/smp.cpp'''
acpi_scan_spots[] need to include the first 1 KB of EBDA.
acpi_scan_spots[0] need to use actual base memory size from BDA
According to spec:
1. The MP Floating Pointer Structure. This structure contains a physical
address
pointer to the MP configuration table and other MP feature information
bytes. When present, this structure indicates that the system conforms to
the MP specification.
This structure must be stored in at least one of the following memory
locations,
because the operating system searches for the MP floating pointer
structure in the
order described below:
a. In the first kilobyte of Extended BIOS Data Area (EBDA), or
b. Within the last kilobyte of system base memory (e.g., 639K-640K for
systems with
640 KB of base memory or 511K-512K for systems with 512 KB of base
memory) if the
EBDA segment is undefined, or
c. In the BIOS ROM address space between 0F0000h and 0FFFFFh.
--
Ticket URL: <https://dev.haiku-os.org/ticket/10663>
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