historical/m0-applesillicon.git/xnu-qemu-arm64-5.1.0/roms/SLOF/slof/entry.S
2024-01-16 11:20:27 -06:00

219 lines
4.6 KiB
ArmAsm

/******************************************************************************
* Copyright (c) 2004, 2008 IBM Corporation
* All rights reserved.
* This program and the accompanying materials
* are made available under the terms of the BSD License
* which accompanies this distribution, and is available at
* http://www.opensource.org/licenses/bsd-license.php
*
* Contributors:
* IBM Corporation - initial implementation
*****************************************************************************/
#include <macros.h>
#define STACKSIZE 0x2000
#
# The generic exception code.
#
# Enter with GPR0 = vector, SPRG0 = saved GPR0
#
.section ".entry_text"
the_handler:
.quad handler
eregs:
/* the_exception_frame is a C variable which is usually
* defined in $(TARG).c
* the_exception_frame can be accessed from paflof through
* the word eregs
* in the case an excpetion is handled paflof will read
* from eregs the values of all registers and print them
* out in the exception handler */
.quad the_exception_frame
handler:
mtsprg 1,1 # SPRG1 = saved GPR1
bcl 20,31,$+4
mflr 1
ld 1,eregs-$+4(1) # GPR1 = address of register save area
.irp i, 2,3,4,5,6,7,8,9,10,11,12,13,14,15, \
16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
std \i,\i*8(1)
.endr # save GPR2..GPR31
li r3, 3 // GPR3 = mode (param_1, param_2)
mr 4,0 // GPR4 = vector
mfsprg 0,0
std 0,0(1) # save GPR0
mfsprg 0,1
std 0,8(1) # save GPR1
cmpwi r4, 0x900 # Decrementer interrupt
bne 0f
mfdec r5 # Save old value of decrementer as reason
lis r0,0x7fff # Set decrementer to highest value
mtdec r0
0:
mfcr 0
std 0,0x100(1)
mfxer 0
std 0,0x108(1)
mfsprg 0,3 # save lr
std 0,0x110(1)
mfsprg 0,2 # save ctr
std 0,0x118(1)
mfsrr0 0
std 0,0x120(1)
mfsrr1 0
std 0,0x128(1)
mfdar 0
std 0,0x130(1)
mfdsisr 0
std 0,0x138(1) # save special regs
bcl 20, 31, over
base:
.align 3
.the_system_stack:
.quad the_system_stack+STACKSIZE-base
over:
mflr r2 /* gpr 2 is the base */
ld r1, .the_system_stack-base(r2) /* load stack pointer */
add r1, r1, r2 /* add base */
li r0, 0
stdu r0, -0x10(r1)
stdu r1, -0x100(r1)
lis 2,engine@ha
ld 0,engine@l(2) # set up entry
mtsrr0 0
ld 2,8+engine@l(2) # set up TOC pointer
rfid
# b .engine # ...and run!
#
# Swap non-volatile client interface regs, plus GPR3..GPR7.
#
swap_ci_regs:
/* save lr */
mflr r0
/* let's find out where our client stack is */
bcl 20, 31, client_over
client_base:
.align 3
.the_client_frame:
.quad the_client_frame-client_base
client_over:
mflr r8 /* gpr 2 is the client_base */
mtlr r0 /* restore the original lr */
ld r0, .the_client_frame-client_base(r8)
add r8, r0, r8 /* add the client_base */
/* r8 now contains the address of the_client_frame */
.irp i, 1,2,3,4,5,6,7, \
13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
ld 0,\i*8(8)
std \i,\i*8(8)
mr \i,0
.endr # swap GPR1..7, GPR13..31
ld 0,0x100(8)
mfcr 9
mtcrf 0xff,0
std 9,0x100(8) # swap CR
ld 0,0x128(8)
mfmsr 9
mtmsrd 0
sync
isync
std 9,0x128(8) # swap MSR
blr
#
# Entry point for the OF client interface.
#
.globl client_entry_point
.section ".opd","aw"
.align 3
client_entry_point:
.quad .client_entry_point,.TOC.@tocbase,0
.previous
.type .client_entry_point,@function
.globl .client_entry_point
.client_entry_point:
mflr 4
bl swap_ci_regs # swap regs
mtlr 4
li 3, 0 # client call
blr
#
# Start the client.
#
.globl call_client
.section ".opd","aw"
.align 3
call_client:
.quad .call_client,.TOC.@tocbase,0
.previous
.type .call_client,@function
.globl .call_client
.call_client: # called with r3 = address, returns r3
mflr 4
mtctr 3
bl swap_ci_regs
/* Check if LE loading */
cmpwi 0,13,1
beq 0f
bctrl
b 1f
0: /* handle LE */
mfmsr 13
xori 13,13,1
mtsrr1 13
mfctr 13
mr 12,13
mtsrr0 13
rfid
#if 0 /* in case we return back, still to be tested */
.long 0x05009f42; /* bcl 20,31,$+4 */
.long 0xa602c87d; /* mflr r14 */
.long 0x1c00ce39; /* addi r14,r14,28 */
.long 0xa600e07d; /* mfmsr r15 */
.long 0x0100ef69; /* xori r15,r15,1 */
.long 0xa603da7d; /* mtsrr0 r14 */
.long 0xa603fb7d; /* mtsrr1 r15 */
.long 0x2400004c; /* rfid */
#endif
1:
bl swap_ci_regs
mtlr 4
li 3, -1 # client app return
blr
# Call another function via pointer in r6
# (arguments can be provided in r3 to r5)
# Destination function should jump back to lr
C_ENTRY(call_c)
mtctr r6
bctr
.global the_system_stack
.lcomm the_system_stack, STACKSIZE, 16