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342 lines
6.9 KiB
ArmAsm

# © IBM Corp. 2022
# Licensed under and subject to the terms of the CC-BY 4.0
# license (https://creativecommons.org/licenses/by/4.0/legalcode).
# Additional rights, including the right to physically implement a softcore
# that is compliant with the required sections of the Power ISA
# Specification, will be available at no cost via the OpenPOWER Foundation.
# This README will be updated with additional information when OpenPOWER's
# license is available.
# boot kernel
# resets to 32BE
# set up translations for starting bios (inc. BE/LE)
# copy modifiable rom data to ram - or do in bios?
# set up msr for running bios (inc. 32/64)
# jump to bios
.include "defines.s"
.macro load32 rx,v
li \rx,0
oris \rx,\rx,\v>>16
ori \rx,\rx,\v&0x0000FFFF
.endm
.macro load16swiz rx,v
li \rx,0
ori \rx,\rx,(\v<<8)&0xFF00
ori \rx,\rx,(\v>>8)&0x00FF
.endm
# constants from linker script, or defsym
.ifdef BIOS_32
# sup MSR cm=1 ce=1 ee=1 pr=0 fp=1 me=1 fe=00 de=0 is=0 ds=0
.set BIOS_MSR,0x0002B000
.else
# sup MSR cm=1 ce=1 ee=1 pr=0 fp=1 me=1 fe=00 de=0 is=0 ds=0
.set BIOS_MSR,0x8002B000
.endif
# erat w2 (test) # word 2 wlc=40:41 rsvd=42 u=44:47 r=48 c=49 wimge=52:56 vf=57 ux/sx=58:59 uw/sw=60:61 ur/sr=62:63
.ifdef BIOS_LE
.set BIOS_ERATW2,0x000000BF
.else
.set BIOS_ERATW2,0x0000003F
.endif
# bios might be able to use one stack during thread startup if careful
.ifndef BIOS_STACK_0
.set BIOS_STACK_0,_stack_0
.endif
.ifndef BIOS_STACK_1
.set BIOS_STACK_1,_stack_1
.endif
.ifndef BIOS_START
.set BIOS_START,0x00010000
.endif
.section .text
.global _start
.org 0x000
_start:
int_000:
b boot_start
# critical input
.org 0x020
int_020:
.ifndef INT_UNHANDLED
b .
.else
b INT_UNHANDLED
.endif
# debug
.org 0x040
int_040:
b .
# dsi
.org 0x060
int_060:
b .
# isi
.org 0x080
int_080:
b .
# external
.org 0x0A0
int_0A0:
b .
# alignment
.org 0x0C0
int_0C0:
b .
# program
.org 0x0E0
int_0E0:
b .
# fp unavailable
.org 0x100
int_100:
b .
# sc
.org 0x120
int_120:
b .
# apu unavailable
.org 0x140
int_140:
b .
# decrementer
.org 0x160
int_160:
b .
# fit
.org 0x180
int_180:
b .
# watchdog
.org 0x1A0
int_1A0:
b .
# dtlb
.org 0x1C0
int_1C0:
b .
# itlb
.org 0x1E0
int_1E0:
b .
# vector unavailable
.org 0x200
int_200:
b .
#
.org 0x220
int_220:
b .
#
.org 0x240
int_240:
b .
#
.org 0x260
int_260:
b .
# doorbell
.org 0x280
int_280:
b .
# doorbell critical
.org 0x2A0
int_2A0:
b .
# doorbell guest
.org 0x2C0
int_2C0:
b .
# doorbell guest critical
.org 0x2E0
int_2E0:
b .
# hvsc
.org 0x300
int_300:
b .
# hvpriv
.org 0x320
int_320:
b .
# lrat
.org 0x340
int_340:
b .
# ------------------------------------------------------------------------------------------------------------------------------
# initial translation
# both erats:
# 00000000 64K: (rom, BE)
# 00010000 64K: (ram, BE or LE)
#
.org 0x400
boot_start:
mfspr r5,tir # who am i?
cmpdi r5,0x00 # skip unless T0
bne init_t123
lis r3,0x8C00 # 32=ecl 36:37=tlbsel (10=i, 11=d)
# derat 31 @00000000
li r0,0x001F # entry #31
li r2,0x0015 # word 2 wlc=40:41 rsvd=42 u=44:47 r=48 c=49 wimge=52:56 vf=57 ux/sx=58:59 uw/sw=60:61 ur/sr=62:63
li r4,0 # word 1 rpn(32:51)=32:51 rpn(22:31)=54:63
li r8,0x023F # word 0 epn=32:51 class=52:53 v=54 x=55 size=56:59 thrd=60:63 size: 0001=4K 0011=64K 0101=1M 0111=16M 1010=1G
mtspr mmucr0,r3
eratwe r2,r0,2
eratwe r4,r0,1
eratwe r8,r0,0
isync
load32 r10,BIOS_ERATW2 # word 2 wlc=40:41 rsvd=42 u=44:47 r=48 c=49 wimge=52:56 vf=57 ux/sx=58:59 uw/sw=60:61 ur/sr=62:63
# derat 30 @<BIOS_START>
li r0,0x001E # entry #30
load32 r4,BIOS_START # word 1 rpn(32:51)=32:51 rpn(22:31)=54:63
load32 r8,BIOS_START
ori r8,r8,0x023F # word 0 epn=32:51 class=52:53 v=54 x=55 size=56:59 thrd=60:63 size: 0001=4K 0011=64K 0101=1M 0111=16M 1010=1G
eratwe r10,r0,2
eratwe r4,r0,1
eratwe r8,r0,0
isync
lis r3,0x8800 # 32=ecl 36:37=tlbsel (10=i, 11=d)
# ierat 15 @00000000
li r0,0x000F # entry #15
li r2,0x003F # word 2 wlc=40:41 rsvd=42 u=44:47 r=48 c=49 wimge=52:56 vf=57 ux/sx=58:59 uw/sw=60:61 ur/sr=62:63
li r4,0 # word 1 rpn(32:51)=32:51 rpn(22:31)=54:63
li r8,0x023F # word 0 epn=32:51 class=52:53 v=54 x=55 size=56:59 thrd=60:63 size: 0001=4K 0011=64K 0101=1M 0111=16M 1010=1G
mtspr mmucr0,r3
eratwe r2,r0,2
eratwe r4,r0,1
eratwe r8,r0,0
isync
# *** leave the init'd entry 14 for MT access to FFFFFFC0
# ierat 13 @<BIOS_START>
li r0,0x000D # entry #13
load32 r4,BIOS_START # word 1 rpn(32:51)=32:51 rpn(22:31)=54:63
load32 r8,BIOS_START
ori r8,r8,0x023F # word 0 epn=32:51 class=52:53 v=54 x=55 size=56:59 thrd=60:63 size: 0001=4K 0011=64K 0101=1M 0111=16M 1010=1G
eratwe r10,r0,2
eratwe r4,r0,1
eratwe r8,r0,0
isync
b init_t0
# ------------------------------------------------------------------------------------------------------------------------------
# init
#
# T0
init_t0:
# set up BIOS msr
load32 r10,BIOS_MSR
mtmsr r10
isync
# can't use load32 unless you can .set BIOS_STACK_0 to the linked value
# load32 r1,BIOS_STACK_0 # @stack_0
# this ignores def
# lis r1,_stack_0@h
# ori r1,r1,_stack_0@l
# this requires data load
lwz r1,stack_0(r0)
b boot_complete
# except T0
init_t123:
# set up BIOS msr
load32 r10,BIOS_MSR
mtmsr r10
isync
# check tir if more than 2 threads possible
lwz r1,stack_1(r0)
b boot_complete
# ------------------------------------------------------------------------------------------------------------------------------
boot_complete:
# set up thread and hop to it
lis r3,main@h
ori r3,r3,main@l
mtctr r3
mfspr r3,tir # who am i?
bctrl
b kernel_return
# ------------------------------------------------------------------------------------------------------------------------------
.org 0x7FC
kernel_return:
b .
# dec
.org 0x800
int_800:
b .
# perf
.org 0x820
int_820:
b .
.org 0x8F0
.section .rodata
stack_0: .long BIOS_STACK_0
stack_1: .long BIOS_STACK_1