Does anyone know why my code halts and raise error when in
AA64,RV64,LA64 UEFI?
lazarus / 64-FPC development

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TYDQ · 2024-08-19 10:32

My full pascal code is in
https://github.com/TYDQSoft/UEFIPascalOS/tree/main(Contains my pascal
OS code and elf2efi code)
I have used my elf2efi utility (Pascal-based program running on
linux,which programmed by me) to converts my elf file to UEFI pecoff
executable.To simulate the elf file executation as a pecoff file,all
position relation(Not absolute address) will not changed by this
program.
This is the my error pascal code segment about where the error occurs
in LA64(LoongArch64,due to its error raising is friendly and according
the error exception,I positioned this error directly on this code):
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure e
fi_initialize(InputImageHandle:efi_handle;InputSystemTable:Pefi_system
_table);[public,alias:'EFI_INITIALIZE'];begin ParentImageHandle:=Input
ImageHandle; GlobalSystemTable:=InputSystemTable;end;And that is where
the error occurs in the main program(Start of the program to where the
error occurs):
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
uefiloader; {$MODE FPC} uses uefi,binarybase,bootconfig,graphics;   
function efi_main(ImageHandle:efi_handle;systemtable:Pefi_system_table
):efi_status;{$ifdef cpux86_64}MS_ABI_Default;{$endif}{$ifdef
cpui386}cdecl;{$endif}[public,alias:'_start'];var {For checking elf
file}    sfsp:Pefi_simple_file_system_protocol;   
fp:Pefi_file_protocol;    efsl:efi_file_system_list;   
i,j,count,procindex:natuint;    status:efi_status;   
finfo:efi_file_info;    finfosize:natuint;    proccontent:Pointer;   
procsize:natuint;    partstr:PWideChar;    gpl:efi_graphics_list;   
isgraphics:boolean;    loaderscreenconfig:screen_config;    {For elf
structure}    header:elf64_header;   
program_headers:^elf64_program_header;   
LowAddress,HighAddress:qword;    PageCount:qword;   
KernelRelocateBase:qword;    RelocateOffset:qword;   
ZeroStart:^qword;    SourceStart,DestStart:^byte;   
KernelEntry:Pointer;    bool:array[1..4] of boolean;    {For loading
elf files}    initparam:Psys_parameter_item;    param:sys_parameter; 
 func:sys_parameter_function;   
funcandparam:sys_parameter_function_and_parameter;    res:Pointer;   
{For memory initializtion}    memorymap:efi_memory_map;   
memoryavailable:efi_memory_result;    addressoffset:natuint;   
allocaddress:natuint;begin   {Initialize the uefi
loader} efi_initialize(ImageHandle,systemtable);I know FPC in other
architecture uses default calling convention and UEFI in architecture
which is not x64 uses this too,Using default calling convention is not
wrong.However,while reading the assembly code generated,I was confused
about why my efi_initialize have error after I convert the elf file to
UEFI pecoff file.Does anyone know why my code raise the error(It is
raised by UEFI internal debugger) and how can I fix it?(Due to my code
cannot pass when in Aarch64,LoongArch,RiscV UEFI)

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TYDQ · 2024-08-21 12:25

Is it too hard for us to respond?

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Laksen · 2024-08-21 22:38

Maybe if you said what failed, and gave examples of the disassembly on
the address where it failed?

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TYDQ · 2024-08-22 03:15

Quote from: Laksen on August 22, 2024, 12:38:59 amMaybe if you said
what failed, and gave examples of the disassembly on the address where
it failed?
This is generated assembly code from fpc,I will mark where the error
occurs:
Code: ASM  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i .section
.text.n_uefi_$$_efi_initialize$pointer$pefi_system_table,"ax"       
.balign 8.globl  UEFI_$$_EFI_INITIALIZE$POINTER$PEFI_SYSTEM_TABLE    
  .type   UEFI_$$_EFI_INITIALIZE$POINTER$PEFI_SYSTEM_TABLE,@functionUE
FI_$$_EFI_INITIALIZE$POINTER$PEFI_SYSTEM_TABLE:.globl  EFI_INITIALIZE 
      .type   EFI_INITIALIZE,@functionEFI_INITIALIZE:.Lc14:# [2874]
begin        addi.d  $sp,$sp,-32.Lc15:        st.d   
$fp,$sp,16.Lc16:        addi.d  $fp,$sp,32.Lc17:# Var InputImageHandle
located at $r3+0, size=OS_64# Var InputSystemTable located at $r3+8,
size=OS_64        st.d    $a0,$sp,0        st.d    $a1,$sp,8# [2875]
ParentImageHandle:=InputImageHandle;
GlobalSystemTable:=InputSystemTable;        move    $t0,$sp       
pcalau12i       $t1,%got_pc_hi20(TC_$UEFI_$$_PARENTIMAGEHANDLE)      
ld.d    $t1,$t1,%got_pc_lo12(TC_$UEFI_$$_PARENTIMAGEHANDLE)       
ld.d    $t0,$t0,0        st.d    $t0,$t1,0 #That is where the error
occurs.        addi.d  $t1,$sp,8        pcalau12i      
$t0,%got_pc_hi20(TC_$UEFI_$$_GLOBALSYSTEMTABLE)        ld.d   
$t0,$t0,%got_pc_lo12(TC_$UEFI_$$_GLOBALSYSTEMTABLE)        ld.d   
$t1,$t1,0        st.d    $t1,$t0,0# [2876] end;        addi.d 
$sp,$fp,-32        ld.d    $fp,$sp,16AArch64 and Riscv64 UEFI internal
debugger don't show the ImageBase and EntryPoint address,So I don't
have the way to find out where the error occurs in disassembly.

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TYDQ · 2024-08-22 07:19

Quote from: Laksen on August 22, 2024, 12:38:59 amMaybe if you said
what failed, and gave examples of the disassembly on the address where
it failed?
I have read the assembly in aarch64 target:
Code: ASM  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i .section
.text.n_uefi_$$_efi_console_get_max_row_and_max_column,"ax"       
.balign 8.globl  UEFI_$$_EFI_CONSOLE_GET_MAX_ROW_AND_MAX_COLUMN      
.type   UEFI_$$_EFI_CONSOLE_GET_MAX_ROW_AND_MAX_COLUMN,@functionUEFI_$
$_EFI_CONSOLE_GET_MAX_ROW_AND_MAX_COLUMN:.globl 
EFI_CONSOLE_GET_MAX_ROW_AND_MAX_COLUMN        .type   EFI_CONSOLE_GET_
MAX_ROW_AND_MAX_COLUMN,@functionEFI_CONSOLE_GET_MAX_ROW_AND_MAX_COLUMN
:.Lc90:// [3330] begin        stp     x29,x30,[sp, #-16]!.Lc91:      
mov     x29,sp.Lc92:        sub     sp,sp,#64// Var maxc located at
sp+0, size=OS_64// Var maxr located at sp+8, size=OS_64// Var
maxcharsize located at sp+16, size=OS_64// Var rescolumn located at
sp+24, size=OS_64// Var resrow located at sp+32, size=OS_64// Var
maxcharindex located at sp+40, size=OS_64// Var status located at
sp+48, size=OS_S64// Var i located at sp+56, size=OS_8// [3331] i:=0;
status:=efi_success; maxcharsize:=2000; maxcharindex:=1;
rescolumn:=80; resrow:=25;        strb    wzr,[sp, #56]        str   
xzr,[sp, #48]        movz    x0,#2000        str     x0,[sp, #16]    
  movz    x0,#1        str     x0,[sp, #40]        movz    x0,#80    
  str     x0,[sp, #24]        movz    x0,#25        str     x0,[sp,
#32]// [3332]
GlobalSystemTable^.ConOut^.SetMode(GlobalSystemTable^.ConOut,0);     
 adrp    x0,TC_$UEFI_$$_GLOBALSYSTEMTABLE        add    
x0,x0,:lo12:TC_$UEFI_$$_GLOBALSYSTEMTABLE        ldr     x0,[x0]     
 ldr     x0,[x0, #64] #that is where error occurs in assembly       
movz    x1,#0        adrp    x2,TC_$UEFI_$$_GLOBALSYSTEMTABLE       
add     x2,x2,:lo12:TC_$UEFI_$$_GLOBALSYSTEMTABLE        ldr    
x2,[x2]        ldr     x2,[x2, #64]        ldr     x2,[x2, #32]      
blr     x2

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Laksen · 2024-08-22 09:48

On la64, what's the value of $t1 when it crashes? Does it match the
value you have updated in the .got?

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TYDQ · 2024-08-22 10:15

Quote from: Laksen on August 22, 2024, 11:48:15 amOn la64, what's the
value of $t1 when it crashes? Does it match the value you have updated
in the .got?
I don't know,the LoongArch UEFI internal debugger don't show me
this.It show me just:
PROGRESS CODE: V03058001 I0
CRMD   0xB0
PRMD   0x4
ECFG  0x800
ESTAT   0x40000
ERA    0xD85C458(The error position)
BADV    0x0(The fault address)
BADI 0x29C00184(The error machine code)
PC 0x00000D85C458(The error position)

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Laksen · 2024-08-22 10:37

Attach a debugger and break on that address?

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TYDQ · 2024-08-22 11:17

Quote from: Laksen on August 22, 2024, 12:37:17 pmAttach a debugger
and break on that address?
UEFI has its internal debugger,but its function doesn't abundant.

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Laksen · 2024-08-22 12:17

If you are using QEMU you can easily use gdb

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TYDQ · 2024-08-22 13:15

Quote from: Laksen on August 22, 2024, 02:17:13 pmIf you are using
QEMU you can easily use gdb
I'm using libvirt and QEMU.

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Laksen · 2024-08-22 14:20

Okay that should work fine I guess. Try and search for how to use gdb
with QEMU

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TYDQ · 2024-08-27 03:59

Quote from: Laksen on August 22, 2024, 04:20:28 pmOkay that should
work fine I guess. Try and search for how to use gdb with QEMU
However,after I edited my elf2efi,the error still occurs in
RV64(Risc-V 64),other three platforms are running successfully.
UEFI internal debugger told me this and this is where error occurs:
Code: ASM  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i .section
.text.n_uefi_$$_efi_initialize$pointer$pefi_system_table,"ax"       
.balign 8.globl  UEFI_$$_EFI_INITIALIZE$POINTER$PEFI_SYSTEM_TABLE    
  .type   UEFI_$$_EFI_INITIALIZE$POINTER$PEFI_SYSTEM_TABLE,@functionUE
FI_$$_EFI_INITIALIZE$POINTER$PEFI_SYSTEM_TABLE:.globl  EFI_INITIALIZE 
      .type   EFI_INITIALIZE,@functionEFI_INITIALIZE:.Lc8:# [2858]
begin        addi    x2,x2,-16        sd      x1,8(x2)        sd     
x8,0(x2)        addi    x8,x2,16        addi    x2,x2,-104# Var
InputImageHandle located in register x10# Var InputSystemTable located
in register x11# Var InputImageHandle located in register x10.La1:#
[2859] ParentImageHandle:=InputImageHandle;
GlobalSystemTable:=InputSystemTable;        auipc  
x12,%got_pcrel_hi(TC_$UEFI_$$_PARENTIMAGEHANDLE)        ld     
x12,%pcrel_lo(.La1)(x12)        sd      x10,0(x12) # where the error
occurs# Var InputSystemTable located in register x11.La2:        auipc
  x10,%got_pcrel_hi(TC_$UEFI_$$_GLOBALSYSTEMTABLE)        ld     
x10,%pcrel_lo(.La2)(x10)        sd      x11,0(x10)# [2860] end;      
ld      x8,104(x2)        ld      x1,112(x2)        addi    x2,x2,120 
      jalr    x0,x1.Lc7:.Le3:        .size  
UEFI_$$_EFI_INITIALIZE$POINTER$PEFI_SYSTEM_TABLE, .Le3 -
UEFI_$$_EFI_INITIALIZE$POINTER$PEFI_SYSTEM_TABLE This is the error
type:
!!!! RISCV64 Exception Type -
000000000000000F(EXCEPT_RISCV_STORE_ACCESS_PAGE_FAULT) !!!!
     t0 = 0x00000000000001000        t1 = 0x00000000083FFF620
                                                                  t2 =
0x00000000000001000        t3 = 0x0FFFFFFFFBC62157E
                                                  t4 =
0x00000000000003E33        t5 = 0x00000000000004FEC
                                 t6 = 0x00000000000000004        s0 =
0x00000000083FFF610
                  s1 = 0x00000000000000013        s2 =
0x00000000000000000
                                                                     
           s3 = 0x00000000000000000        s4 = 0x000000000BFE00000
                                                                  s5 =
0x0000000017FFFE018        s6 = 0x08000000A00006800
                                                  s7 =
0x00000000000000004        s8 = 0x00000000000002000
                                 s9 = 0x00000000080043710       s10 =
0x00000000000000000
                 s11 = 0x00000000000000000        a0 =
0x0000000017F2AB998
                                                                     
           a1 = 0x0000000017FFFE018        a2 = 0x00000000000000000
                                                                  a3 =
0x00000000000000000        a4 = 0x0000000017FFFE018
                                                  a5 =
0x0000000017E2DFA88        a6 = 0x00000000000000006
                                 a7 = 0x0000000000000000E      zero =
0x00000000000000000
                  ra = 0x0000000017E2DFAD0        sp =
0x0000000017FE14D78
                                                                     
           gp = 0x00000000000000000        tp = 0x0000000008004E000
                                                                sepc =
0x0000000017E2E06BC   sstatus = 0x08000000200006120
                                               stval =
0x00000000000000000

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Laksen · 2024-08-27 11:04

x12 is 0

Looks like there's a mix of pcrel and got_pcrel

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Laksen · 2024-08-27 15:34

Nevermind, that's probably not the issue. You need to dig deeper. I
would advice setting a breakpoint with GDB. It sounds like that
inbuilt debugger is quite tedious to work with

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TYDQ · 2024-08-28 03:54

Quote from: Laksen on August 27, 2024, 05:34:39 pmNevermind, that's
probably not the issue. You need to dig deeper. I would advice setting
a breakpoint with GDB. It sounds like that inbuilt debugger is quite
tedious to work with
OK,I will try to do this.According to UEFI spec,ImageHandle is in
x10(a0),SystemTable is in x11(a1).This can't be errorous.I will dig
into it deeper.