From 73eee3e599964e08bc02ebf9a16d0b182469e355 Mon Sep 17 00:00:00 2001
From: jn <jn@ccc.ac>
Date: Mon, 30 Jan 2023 20:42:21 +0100
Subject: [PATCH] kernel/vfs: Don't ignore buffer length in write(stream)

---
 applications/sh/main.asm |  4 ++++
 kernel/vfs.asm           | 16 +++++++++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/applications/sh/main.asm b/applications/sh/main.asm
index 5965148..67f58a5 100644
--- a/applications/sh/main.asm
+++ b/applications/sh/main.asm
@@ -233,16 +233,19 @@ shell_clear_buffer:
 ; outputs:
 ; none
 print_character_to_terminal:
+    push r0
     push r1
     push r2
 
     mov.8 [shell_char_buffer], r0
+    mov r0, 1
     mov r1, [shell_terminal_stream_struct_ptr]
     mov r2, shell_char_buffer
     call write
 
     pop r2
     pop r1
+    pop r0
     ret
 
 ; print a string to the terminal
@@ -257,6 +260,7 @@ print_str_to_terminal:
     mov r1, [shell_terminal_stream_struct_ptr]
     mov r2, r0
 print_str_to_terminal_loop:
+    mov r0, 1
     call write
     inc r2
     cmp.8 [r2], 0x00
diff --git a/kernel/vfs.asm b/kernel/vfs.asm
index f45b766..4d45785 100644
--- a/kernel/vfs.asm
+++ b/kernel/vfs.asm
@@ -91,7 +91,7 @@ stream_read:
 
 ; write specified number of bytes into the specified file
 ; inputs:
-; r0: number of bytes to write (ignored if file struct is a stream)
+; r0: number of bytes to write
 ; r1: pointer to file struct
 ; r2: pointer to source buffer (always 4 bytes if file struct is a stream)
 ; outputs:
@@ -111,6 +111,20 @@ write:
     pop r3
     ret
 stream_write:
+    push r31
+    push r2
+
+    mov r31, r0 ; number of bytes to write = loop count
+stream_write_loop:
+    call stream_write_char
+    inc r2
+    loop stream_write_loop
+
+    pop r2
+    pop r31
+    ret
+
+stream_write_char:
     push r0
     push r1