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>
This commit is contained in:
Andres Salomon
2010-06-18 17:46:53 -04:00
committed by H. Peter Anvin
parent 7e27d6e778
commit fd699c7655
9 changed files with 173 additions and 8 deletions

View File

@ -70,6 +70,14 @@ struct sys_desc_table {
__u8 table[14];
};
/* Gleaned from OFW's set-parameters in cpu/x86/pc/linux.fth */
struct olpc_ofw_header {
__u32 ofw_magic; /* OFW signature */
__u32 ofw_version;
__u32 cif_handler; /* callback into OFW */
__u32 irq_desc_table;
} __attribute__((packed));
struct efi_info {
__u32 efi_loader_signature;
__u32 efi_systab;
@ -92,7 +100,8 @@ struct boot_params {
__u8 hd0_info[16]; /* obsolete! */ /* 0x080 */
__u8 hd1_info[16]; /* obsolete! */ /* 0x090 */
struct sys_desc_table sys_desc_table; /* 0x0a0 */
__u8 _pad4[144]; /* 0x0b0 */
struct olpc_ofw_header olpc_ofw_header; /* 0x0b0 */
__u8 _pad4[128]; /* 0x0c0 */
struct edid_info edid_info; /* 0x140 */
struct efi_info efi_info; /* 0x1c0 */
__u32 alt_mem_k; /* 0x1e0 */