94 строки
2.3 KiB
ArmAsm
94 строки
2.3 KiB
ArmAsm
/*
|
|
* arch/ppc/platforms/gemini_prom.S
|
|
*
|
|
* Not really prom support code (yet), but sort of anti-prom code. The current
|
|
* bootloader does a number of things it shouldn't and doesn't do things that it
|
|
* should. The stuff in here is mainly a hodge-podge collection of setup code
|
|
* to get the board up and running.
|
|
* ---Dan
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <asm/reg.h>
|
|
#include <asm/page.h>
|
|
#include <platforms/gemini.h>
|
|
#include <asm/ppc_asm.h>
|
|
|
|
/*
|
|
* On 750's the MMU is on when Linux is booted, so we need to clear out the
|
|
* bootloader's BAT settings, make sure we're in supervisor state (gotcha!),
|
|
* and turn off the MMU.
|
|
*
|
|
*/
|
|
|
|
_GLOBAL(gemini_prom_init)
|
|
#ifdef CONFIG_SMP
|
|
/* Since the MMU's on, get stuff in rom space that we'll need */
|
|
lis r4,GEMINI_CPUSTAT@h
|
|
ori r4,r4,GEMINI_CPUSTAT@l
|
|
lbz r5,0(r4)
|
|
andi. r5,r5,3
|
|
mr r24,r5 /* cpu # used later on */
|
|
#endif
|
|
mfmsr r4
|
|
li r3,MSR_PR /* ensure supervisor! */
|
|
ori r3,r3,MSR_IR|MSR_DR
|
|
andc r4,r4,r3
|
|
mtmsr r4
|
|
isync
|
|
#if 0
|
|
/* zero out the bats now that the MMU is off */
|
|
prom_no_mmu:
|
|
li r3,0
|
|
mtspr SPRN_IBAT0U,r3
|
|
mtspr SPRN_IBAT0L,r3
|
|
mtspr SPRN_IBAT1U,r3
|
|
mtspr SPRN_IBAT1L,r3
|
|
mtspr SPRN_IBAT2U,r3
|
|
mtspr SPRN_IBAT2L,r3
|
|
mtspr SPRN_IBAT3U,r3
|
|
mtspr SPRN_IBAT3L,r3
|
|
|
|
mtspr SPRN_DBAT0U,r3
|
|
mtspr SPRN_DBAT0L,r3
|
|
mtspr SPRN_DBAT1U,r3
|
|
mtspr SPRN_DBAT1L,r3
|
|
mtspr SPRN_DBAT2U,r3
|
|
mtspr SPRN_DBAT2L,r3
|
|
mtspr SPRN_DBAT3U,r3
|
|
mtspr SPRN_DBAT3L,r3
|
|
#endif
|
|
|
|
/* the bootloader (as far as I'm currently aware) doesn't mess with page
|
|
tables, but since we're already here, might as well zap these, too */
|
|
li r4,0
|
|
mtspr SPRN_SDR1,r4
|
|
|
|
li r4,16
|
|
mtctr r4
|
|
li r3,0
|
|
li r4,0
|
|
3: mtsrin r3,r4
|
|
addi r3,r3,1
|
|
bdnz 3b
|
|
|
|
#ifdef CONFIG_SMP
|
|
/* The 750 book (and Mot/IBM support) says that this will "assist" snooping
|
|
when in SMP. Not sure yet whether this should stay or leave... */
|
|
mfspr r4,SPRN_HID0
|
|
ori r4,r4,HID0_ABE
|
|
mtspr SPRN_HID0,r4
|
|
sync
|
|
#endif /* CONFIG_SMP */
|
|
blr
|
|
|
|
/* apparently, SMon doesn't pay attention to HID0[SRST]. Disable the MMU and
|
|
branch to 0xfff00100 */
|
|
_GLOBAL(_gemini_reboot)
|
|
lis r5,GEMINI_BOOT_INIT@h
|
|
ori r5,r5,GEMINI_BOOT_INIT@l
|
|
li r6,MSR_IP
|
|
mtspr SPRN_SRR0,r5
|
|
mtspr SPRN_SRR1,r6
|
|
rfi
|