| 1 | /* |
| 2 | * Broadcom's CFE specific prom routines |
| 3 | * |
| 4 | * Copyright (C) 2007-2008 Gabor Juhos <juhosg@openwrt.org> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify it |
| 7 | * under the terms of the GNU General Public License version 2 as published |
| 8 | * by the Free Software Foundation. |
| 9 | * |
| 10 | */ |
| 11 | |
| 12 | #include <linux/types.h> |
| 13 | #include <linux/init.h> |
| 14 | |
| 15 | #include <asm/bootinfo.h> |
| 16 | #include <asm/addrspace.h> |
| 17 | |
| 18 | #include <prom/cfe.h> |
| 19 | #include "prom_read.h" |
| 20 | |
| 21 | /* |
| 22 | * CFE based boards |
| 23 | */ |
| 24 | #define CFE_EPTSEAL 0x43464531 /* CFE1 is the magic number to recognize CFE |
| 25 | from other bootloaders */ |
| 26 | |
| 27 | static int cfe_found; |
| 28 | |
| 29 | static u32 cfe_handle; |
| 30 | static u32 cfe_entry; |
| 31 | static u32 cfe_seal; |
| 32 | |
| 33 | int __init cfe_present(void) |
| 34 | { |
| 35 | /* |
| 36 | * This method only works, when we are booted directly from the CFE. |
| 37 | */ |
| 38 | u32 a1 = (u32) fw_arg1; |
| 39 | |
| 40 | if (cfe_found) |
| 41 | return 1; |
| 42 | |
| 43 | cfe_handle = (u32) fw_arg0; |
| 44 | cfe_entry = (u32) fw_arg2; |
| 45 | cfe_seal = (u32) fw_arg3; |
| 46 | |
| 47 | /* Check for CFE by finding the CFE magic number */ |
| 48 | if (cfe_seal != CFE_EPTSEAL) |
| 49 | return 0; |
| 50 | |
| 51 | /* cfe_a1_val must be 0, because only one CPU present in the ADM5120 */ |
| 52 | if (a1 != 0) |
| 53 | return 0; |
| 54 | |
| 55 | /* The cfe_handle, and the cfe_entry must be kernel mode addresses */ |
| 56 | if ((cfe_handle < KSEG0) || (cfe_entry < KSEG0)) |
| 57 | return 0; |
| 58 | |
| 59 | cfe_found = 1; |
| 60 | return 1; |
| 61 | } |
| 62 | |
| 63 | char *cfe_getenv(char *envname) |
| 64 | { |
| 65 | if (cfe_found == 0) |
| 66 | return NULL; |
| 67 | |
| 68 | return NULL; |
| 69 | } |
| 70 | |
