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Trying to debug failing TFTP open

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This commit is contained in:
Thomas Oltmann 2025-07-09 19:29:27 +02:00
parent be2d14de91
commit 093969301e
1 changed files with 44 additions and 31 deletions
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75
lboot.S
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@ -89,6 +89,8 @@ _start: cli
add $12, %sp
mov tx_buf+20, %eax
mov %eax, server_ip
mov tx_buf+24, %eax
mov %eax, gateway_ip
mov $msg_unreal, %si
call print
@ -323,16 +325,30 @@ tftp_open: push %ecx
push %bp
mov %sp, %bp
mov %esi, %ebx
mov $msg_topen, %si
call print
push $PACKET_SIZE
push $69<<8
mov $128, %ecx
sub %cx, %sp
sub %cx, %sp
mov %ss, %edi
shl $4, %edi
add %esp, %edi
xor %ax, %ax
cld
addr32 rep stosb
mov %ebx, %esi
mov $6, %ecx
mov %ss, %edi
shl $4, %edi
add %esp, %edi
cld
addr32 rep movsb
push $0
push $0
push gateway_ip+2
push gateway_ip
push server_ip+2
push server_ip
push $0
@ -348,6 +364,9 @@ tftp_open: push %ecx
tftp_close: push %bp
mov %sp, %bp
mov $msg_tclose, %si
call print
push $0
pxe_call PXE_TFTP_CLOSE
@ -359,6 +378,9 @@ tftp_read: push %ebx
push %bp
mov %sp, %bp
mov $msg_tread, %si
call print
push %cs
push $tx_buf
push $0
@ -377,7 +399,14 @@ out_of_mem: mov $msg_memerr, %si
jmp hang
// print: print NUL-terminated string pointed to by SI
print: xor %bx, %bx
print: push %eax
push %ebx
push %edx
push %esi
push %bp
mov %sp, %bp
xor %bx, %bx
_prnext: mov $COM1+5, %dx
inb %dx, %al
@ -395,7 +424,12 @@ _prnext: mov $COM1+5, %dx
int $0x10
jmp _prnext
_prdone: ret
_prdone: leave
pop %esi
pop %edx
pop %ebx
pop %eax
ret
// long: Enter long mode
long:
@ -434,33 +468,8 @@ long:
hang: hlt
jmp hang
_pcerr: push %cx
mov $msg_pcerr, %si
_pcerr: mov $msg_pcerr, %si
call print
pop %cx
push %cx
xor %bx, %bx
mov %ch, %bl
mov hex_digits(%bx), %bl
mov %bx, tx_buf
mov $tx_buf, %si
call print
pop %cx
push %cx
xor %bx, %bx
mov %cl, %bl
mov hex_digits(%bx), %bl
mov %bx, tx_buf
mov $tx_buf, %si
call print
pop %cx
jmp hang
// gdt16: Protected mode / Unreal mode 16-bit GDT
@ -522,11 +531,15 @@ msg_long: .asciz " * Long Mode\r\n"
msg_pserr: .asciz "panic: Missing !PXE structure.\r\n"
msg_pcerr: .asciz "panic: PXE call failed.\r\n"
msg_memerr: .asciz "panic: Out of heap space.\r\n"
msg_topen: .asciz "tftp_open\r\n"
msg_tclose: .asciz "tftp_close\r\n"
msg_tread: .asciz "tftp_read\r\n"
fn_initrd: .asciz "initrd"
pxe_api: .long 0
server_ip: .space 4
gateway_ip: .space 4
heap_ptr: .long 0
heap_end: .long 0