Make it run on UEFI!

[rrq/jonasforth.git] / main.asm

diff --git a/main.asm b/main.asm
index 4e1a05fa1253d00f6a3b85b1a3ceeb46286bcdf6..4ed478d0743f7f75d584f2632cc377e454fa98f8 100644 (file)
--- 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, '"'
@@ -452,10 +483,6 @@ read_string_buffer:
   ;; We borrow READ_STRING's buffer. They won't mind.
   mov [READ_STRING.length], 0
 
-  ;; Skip space ([TODO]: Shouldn't we do this while parsing instead?)
-  inc [input_buffer]
-  dec [input_buffer_length]
-
 .read_char:
   mov rbx, [input_buffer]
   mov al, [rbx]
@@ -584,7 +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
@@ -624,8 +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.