Can anybody help me with these error messages, please? ≽^•⩊•^≼

Question

Here is the code (written in assebly at&t syntax):

.section .data
    .equ N, 1024
    v: .skip N * 4
    fin: .string "input.txt"
    fout: .string "output.txt"
    descriptor: .long 0
    sz: .long 0
    n: .long 0
    Q: .long 0
    x: .long 0
    y: .long 0
    p: .long 0
    q: .long 0
    format_int: .string "%d"
    format_output: .string "fd:(%d,%d)\n"
    format_failure: .string "fd:(0,0)\n"
    type: .long 0
    buffer: .space 256           

.section .text
    .global _start

_start:
    movl $5, %eax             
    movl $fin, %ebx          
    movl $0, %ecx             
    movl $0, %edx             
    int $0x80                
    movl %eax, %edi           

    movl $5, %eax            
    movl $fout, %ebx          
    movl $577, %ecx           
    movl $438, %edx            
    int $0x80                
    movl %eax, %esi          
    
    push %edi            # main.S:37: Error: operand type mismatch for `push'
    lea buffer, %eax  
    push %eax            # main.S:39: Error: operand type mismatch for `push'
    
    movl $3, %eax            
    movl $4, %edx          
    int $0x80               
    movl %eax, Q           

.loop:
    cmpl $0, Q
    jle .end

    push %edi       # main.S:50: Error: operand type mismatch for `push'            
    push $buffer             
    movl $3, %eax           
    movl $4, %edx          
    int $0x80              
    movl %eax, type         

    cmpl $1, type
    je .add
    cmpl $2, type
    je .get
    cmpl $3, type
    je .delete
    cmpl $4, type
    je .defragmentation

.add:
    call ADD
    jmp .decrement

.get:
    push descriptor
    push %edi # main.S:72: Error: operand type mismatch for `push
    push $buffer
    movl $3, %eax           
    movl $4, %edx          
    int $0x80
    call GET
    jmp .decrement

.delete:
    call DELETE
    jmp .decrement

.defragmentation:
    call DEFRAGMENTATION
    jmp .decrement

.decrement:
    subl $1, Q
    jmp .loop

.end:
    movl $6, %eax            
    movl %edi, %ebx           
    int $0x80              

    movl $6, %eax            
    movl %esi, %ebx        
    int $0x80                 

    movl $1, %eax           
    xor %ebx, %ebx           
    int $0x80                

ADD:
    push %edi      # main.S:106: Error: operand type mismatch for `push'
    push n
    push $buffer
    movl $3, %eax            
    movl $4, %edx            
    int $0x80
    movl %eax, n

    .add_loop:
        cmpl $0, n
        jle .add_end

        push %edi       # main.S:118: Error: operand type mismatch for `push'
        push descriptor
        push sz
        push $buffer
        movl $3, %eax        
        movl $4, %edx       
        int $0x80
        movl %eax, descriptor
        movl %ebx, sz

        movl sz, %eax
        addl $7, %eax
        shrl $3, %eax
        movl %eax, sz

        movl $1, ok

        movl $0, %ecx
        .inner_loop:
            cmpl $N, sz
            jge .found_space

            movl $1, ok
            movl $0, %ebx
            .check_space:
                cmpl sz, %ebx
                jge .space_checked
                cmpl $0, v(%ecx,%ebx, 4)
                jne .not_available
                incl %ebx
                jmp .check_space

            .not_available:
                movl $0, ok
                jmp .space_checked

            .space_checked:
                cmpl $1, ok
                jne .next_space

                movl $0, %ebx
                .allocate_space:
                    cmpl sz, %ebx
                    jge .allocated
                    movl $descriptor, v(%ecx, %ebx, 4)
                    incl %ebx
                    jmp .allocate_space

                .allocated:
                    push %edi      # main.S:167: Error: operand type mismatch for `push'
                    push descriptor
                    push %ecx      # main.S:169: Error: operand type mismatch for `push'
                    push sz
                    push format_output 
                    movl $4, %eax        
                    movl %esi, %ebx      
                    movl $buffer, %ecx  
                    movl $256, %edx      
                    int $0x80
                    jmp .add_end

            .next_space:
                incl %ecx
                jmp .inner_loop

        .found_space:
            push descriptor
            push format_failure
            movl $4, %eax         
            movl %esi, %ebx      
            movl $buffer, %ecx   
            movl $256, %edx       
            int $0x80

        subl $1, n
        jmp .add_loop

    .add_end:
        ret


min:
    cmp %ebx, %eax     
    jle .min_return       
    mov %ebx, %eax        
.min_return:
    ret


max:
    cmp %ebx, %eax      
    jge .max_return        
    mov %ebx, %eax        
.max_return:
    ret

GET:
  
    movl $N, x
    movl $0, y

    movl $0, %ecx
    .get_loop:
        cmpl $N, %ecx
        jge .get_end
        
        movl v(,%ecx,4), %eax  
        cmpl descriptor, %eax
        jne .next_get

       
        movl %ecx, %eax
        call min
        movl %eax, x
        movl %ecx, %eax
        call max
        movl %eax, y

    .next_get:
        incl %ecx
        jmp .get_loop

    .get_end:
        cmpl $N, x
        je .not_found
        jmp .output_get

    .not_found:
        movl $0, x

    .output_get:
        push x
        push y
        push format_get
        movl $4, %eax        
        movl $1, %ebx       
        movl $buffer, %ecx   
        movl $256, %edx     
        int $0x80           
        addl $16, %esp
        ret
DELETE:
    push descriptor
    push format_int

    push $buffer            
    movl $3, %eax           
    movl $4, %edx             
    int $0x80                
    movl %eax, descriptor     

    movl $0, %ecx
    .delete_loop:
        cmpl $N, %ecx
        jge .delete_end

        movl v(,%ecx,4), %eax  
        cmpl descriptor, %eax
        jne .next_delete

     
        movl $0, v(,%ecx,4)


    .next_delete:
        incl %ecx
        jmp .delete_loop

    .delete_end:
      
        movl $0, %ecx
        .output_delete:
            cmpl $N, %ecx
            jge .delete_output_end

            cmpl $0, v(,%ecx,4)
            je .next_output

            push v(,%ecx,4)
            push format_output
            
            movl $4, %eax          
            movl $1, %ebx            
            movl $buffer, %ecx      
            movl $256, %edx        
            int $0x80
        
            call GET
            jmp .next_output

        .next_output:
        incl %ecx
        jmp .output_delete

    .delete_output_end:
        ret
DEFRAGMENTATION:
    movl p, %eax
    movl q, %ebx
    movl $0, %eax
    movl $0, %ebx

    .defrag_loop:
        cmpl $N, %ebx
        jge .defrag_end

        cmpl $0, v(,%ebx, 4)
        je .skip
        movl v(,%ebx,4), %eax
        movl %eax, v(,%eax,4)
        movl $0, v(,%ebx,4)
        incl %eax

    .skip:
        incl %ebx
        jmp .defrag_loop

    .defrag_end:
        movl $0, %ecx
        .output_defrag:
            cmpl $N, %ecx
            jge .defrag_output_end

            cmpl $0, v(, %ecx, 4)
            je .next_defrag_output

            push v(,%ecx, 4)
            push format_output
            
            movl $4, %eax              
            movl $1, %ebx              
            movl $buffer, %ecx          
            movl $256, %edx            
            int $0x80                   

            addl $12, %esp
            call GET
            jmp .next_defrag_output

        .next_defrag_output:
        incl %ecx
        jmp .output_defrag

    .defrag_output_end:
        ret

When I try to compile it, i run into these errors:

main.S: Assembler messages:
main.S:37: Error: operand type mismatch for `push'
main.S:39: Error: operand type mismatch for `push'
main.S:50: Error: operand type mismatch for `push'
main.S:72: Error: operand type mismatch for `push'
main.S:106: Error: operand type mismatch for `push'
main.S:118: Error: operand type mismatch for `push'
main.S:167: Error: operand type mismatch for `push'
main.S:169: Error: operand type mismatch for `push'

I'm sure they are all related to each other. Not sure if it is relevant, but this is the input I used:

10 (no of operations)
4  (defrag)
3  (delete)
1  (add)
2  (get)
124
109 32 (fd, fd_size)
196 39
197 16
219 25

I realized I needed to load values into registers before using push. I replaced push descriptor with movl descriptor, %eax followed by push %eax, and similarly did this for other memory addresses like buffer. It still didn't work, so I must not be understanding something really fundamental...