| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Not really prom support code (yet), but sort of anti-prom code. The current |
| 3 | * bootloader does a number of things it shouldn't and doesn't do things that it |
| 4 | * should. The stuff in here is mainly a hodge-podge collection of setup code |
| 5 | * to get the board up and running. |
| 6 | * ---Dan |
| 7 | */ |
| 8 | |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | #include <asm/reg.h> |
| 10 | #include <asm/page.h> |
| 11 | #include <platforms/gemini.h> |
| 12 | #include <asm/ppc_asm.h> |
| 13 | |
| 14 | /* |
| 15 | * On 750's the MMU is on when Linux is booted, so we need to clear out the |
| 16 | * bootloader's BAT settings, make sure we're in supervisor state (gotcha!), |
| 17 | * and turn off the MMU. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | _GLOBAL(gemini_prom_init) |
| 22 | #ifdef CONFIG_SMP |
| 23 | /* Since the MMU's on, get stuff in rom space that we'll need */ |
| 24 | lis r4,GEMINI_CPUSTAT@h |
| 25 | ori r4,r4,GEMINI_CPUSTAT@l |
| 26 | lbz r5,0(r4) |
| 27 | andi. r5,r5,3 |
| 28 | mr r24,r5 /* cpu # used later on */ |
| 29 | #endif |
| 30 | mfmsr r4 |
| 31 | li r3,MSR_PR /* ensure supervisor! */ |
| 32 | ori r3,r3,MSR_IR|MSR_DR |
| 33 | andc r4,r4,r3 |
| 34 | mtmsr r4 |
| 35 | isync |
| 36 | #if 0 |
| 37 | /* zero out the bats now that the MMU is off */ |
| 38 | prom_no_mmu: |
| 39 | li r3,0 |
| 40 | mtspr SPRN_IBAT0U,r3 |
| 41 | mtspr SPRN_IBAT0L,r3 |
| 42 | mtspr SPRN_IBAT1U,r3 |
| 43 | mtspr SPRN_IBAT1L,r3 |
| 44 | mtspr SPRN_IBAT2U,r3 |
| 45 | mtspr SPRN_IBAT2L,r3 |
| 46 | mtspr SPRN_IBAT3U,r3 |
| 47 | mtspr SPRN_IBAT3L,r3 |
| 48 | |
| 49 | mtspr SPRN_DBAT0U,r3 |
| 50 | mtspr SPRN_DBAT0L,r3 |
| 51 | mtspr SPRN_DBAT1U,r3 |
| 52 | mtspr SPRN_DBAT1L,r3 |
| 53 | mtspr SPRN_DBAT2U,r3 |
| 54 | mtspr SPRN_DBAT2L,r3 |
| 55 | mtspr SPRN_DBAT3U,r3 |
| 56 | mtspr SPRN_DBAT3L,r3 |
| 57 | #endif |
| 58 | |
| 59 | /* the bootloader (as far as I'm currently aware) doesn't mess with page |
| 60 | tables, but since we're already here, might as well zap these, too */ |
| 61 | li r4,0 |
| 62 | mtspr SPRN_SDR1,r4 |
| 63 | |
| 64 | li r4,16 |
| 65 | mtctr r4 |
| 66 | li r3,0 |
| 67 | li r4,0 |
| 68 | 3: mtsrin r3,r4 |
| 69 | addi r3,r3,1 |
| 70 | bdnz 3b |
| 71 | |
| 72 | #ifdef CONFIG_SMP |
| 73 | /* The 750 book (and Mot/IBM support) says that this will "assist" snooping |
| 74 | when in SMP. Not sure yet whether this should stay or leave... */ |
| 75 | mfspr r4,SPRN_HID0 |
| 76 | ori r4,r4,HID0_ABE |
| 77 | mtspr SPRN_HID0,r4 |
| 78 | sync |
| 79 | #endif /* CONFIG_SMP */ |
| 80 | blr |
| 81 | |
| 82 | /* apparently, SMon doesn't pay attention to HID0[SRST]. Disable the MMU and |
| 83 | branch to 0xfff00100 */ |
| 84 | _GLOBAL(_gemini_reboot) |
| 85 | lis r5,GEMINI_BOOT_INIT@h |
| 86 | ori r5,r5,GEMINI_BOOT_INIT@l |
| 87 | li r6,MSR_IP |
| 88 | mtspr SPRN_SRR0,r5 |
| 89 | mtspr SPRN_SRR1,r6 |
| 90 | rfi |
