X-Git-Url: https://git.rrq.au/?a=blobdiff_plain;f=main.asm;h=4ed478d0743f7f75d584f2632cc377e454fa98f8;hb=a0c4c60159c79c8d9af3d08e01bacfa354232c3b;hp=a670b343e99c1a1f0154f0eab083ef6eb1e6cc1a;hpb=7677dbbdce584a64e63946b39879f5edd114f36a;p=rrq%2Fjonasforth.git diff --git a/main.asm b/main.asm index a670b34..4ed478d 100644 --- a/main.asm +++ b/main.asm @@ -1,6 +1,6 @@ ;; vim: syntax=fasm -format ELF64 executable +include "uefi.asm" ;; "Syscalls" {{{ @@ -22,10 +22,46 @@ format ELF64 executable ;; ;; Clobbers: RAX, RCX, R11, RDI, RSI macro sys_print_string { - mov rax, 1 - mov rdi, 1 - mov rsi, rcx - syscall + push r8 + push r9 + push r10 + + call uefi_print_string + + pop r10 + pop r9 + pop r8 +} + +;; Read a character from the user into the given buffer. +;; +;; Input: +;; - RSI = Character buffer +;; +;; Output: +;; - BYTE [RSI] = Character +;; +;; Clobbers: RAX, RCX, R11, RDI, RSI, RDX +macro sys_read_char { + push rbx + push r8 + push r9 + push r10 + push r15 + + mov rcx, rsi + call uefi_read_char + + pop r15 + pop r10 + pop r9 + pop r8 + pop rbx +} + +macro sys_terminate code { + mov rax, code + call uefi_terminate } ;; }}} @@ -87,9 +123,7 @@ macro forth_asm label, name, immediate { .start: } -segment readable executable - -entry main +section '.text' code readable executable include "impl.asm" ; Misc. subroutines include "bootstrap.asm" ; Forth words encoded in Assembly @@ -98,6 +132,8 @@ main: cld ; Clear direction flag so LODSQ does the right thing. mov rbp, return_stack_top ; Initialize return stack + call uefi_initialize + mov rax, MAIN jmp qword [rax] @@ -258,9 +294,7 @@ forth_asm TELL, 'TELL' ;; Exit the program cleanly. forth_asm TERMINATE, 'TERMINATE' - mov rax, $3C - mov rdi, 0 - syscall + sys_terminate 0 ;; Duplicate a pair of elements. forth_asm PAIRDUP, '2DUP' @@ -422,11 +456,8 @@ forth_asm READ_STRING, 'S"' mov [.length], 0 .read_char: - mov rax, 0 - mov rdi, 0 mov rsi, .char_buffer - mov rdx, 1 - syscall + sys_read_char mov al, [.char_buffer] cmp al, '"' @@ -580,7 +611,7 @@ forth INPUT_LENGTH, 'INPUT-LENGTH' dq LIT, input_buffer_length dq EXIT -segment readable writable +section '.data' readable writable ;; The LATEST variable holds a pointer to the word that was last added to the ;; dictionary. This pointer is updated as new words are added, and its value is @@ -620,8 +651,6 @@ here_top rq $4000 rq $2000 return_stack_top: -segment readable - ;; We store some Forth code in sys.f that defined common words that the user ;; would expect to have available at startup. To execute these words, we just ;; include the file directly in the binary, and then interpret it at startup.