path: root/Documentation
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authorAndres Salomon <dilinger@queued.net>2010-06-18 17:46:53 -0400
committerH. Peter Anvin <hpa@linux.intel.com>2010-06-18 14:54:36 -0700
commitfd699c76552bbfa66631f019be415a87dbb08237 (patch)
tree49f136f22fc94230af214f9c9c21a6fc0b7180e1 /Documentation
parent7e27d6e778cd87b6f2415515d7127eba53fe5d02 (diff)
x86, olpc: Add support for calling into OpenFirmware
Add support for saving OFW's cif, and later calling into it to run OFW commands. OFW remains resident in memory, living within virtual range 0xff800000 - 0xffc00000. A single page directory entry points to the pgdir that OFW actually uses, so rather than saving the entire page table, we grab and install that one entry permanently in the kernel's page table. This is currently only used by the OLPC XO. Note that this particular calling convention breaks PAE and PAT, and so cannot be used on newer x86 hardware. Signed-off-by: Andres Salomon <dilinger@queued.net> LKML-Reference: <20100618174653.7755a39a@dev.queued.net> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'Documentation')
1 files changed, 1 insertions, 0 deletions
diff --git a/Documentation/x86/zero-page.txt b/Documentation/x86/zero-page.txt
index feb37e177010..cf5437deda81 100644
--- a/Documentation/x86/zero-page.txt
+++ b/Documentation/x86/zero-page.txt
@@ -18,6 +18,7 @@ Offset Proto Name Meaning
080/010 ALL hd0_info hd0 disk parameter, OBSOLETE!!
090/010 ALL hd1_info hd1 disk parameter, OBSOLETE!!
0A0/010 ALL sys_desc_table System description table (struct sys_desc_table)
+0B0/010 ALL olpc_ofw_header OLPC's OpenFirmware CIF and friends
140/080 ALL edid_info Video mode setup (struct edid_info)
1C0/020 ALL efi_info EFI 32 information (struct efi_info)
1E0/004 ALL alk_mem_k Alternative mem check, in KB

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