From d7df8501d67b7f1aa5e4416ba6d34d3acc023952 Mon Sep 17 00:00:00 2001
From: Paul Mathieu <paul@ponteilla.net>
Date: Sat, 4 Oct 2025 00:27:06 +0200
Subject: [PATCH] Last fixes tonight

---
 src/Makefile |  9 ++++-----
 src/ftpget.c |  8 ++++----
 src/stdlib.c | 40 +++++++++++++++++++++-------------------
 3 files changed, 29 insertions(+), 28 deletions(-)

diff --git a/src/Makefile b/src/Makefile
index 761a44c..45a11c7 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -39,20 +39,19 @@ polio.elf: polio-main.o polio.s fat12.o paracomm.o stdlib.o
 paracli.elf: LDFLAGS += -T doscom.ld
 paracli.elf: paracli.s paracomm.o
 
-dos-programs = mushroom.elf hello.elf ftpget.elf
-$(dos-programs): LDFLAGS += -T doscom.ld
+dos-programs = mushroom.com hello.com ftpget.com
+$(dos-programs:.com=.elf): LDFLAGS += -T doscom.ld
 
 mushroom.elf: mushroom.s
 hello.elf: hello.o stdlib.o crt0.s
 ftpget.elf: ftpget.o stdlib.o crt0.s
 
-polos.img: fat12boot.bin polmon.com polio.com mushroom.com hello.com
+polos.img: fat12boot.bin polmon.com polio.com $(dos-programs)
 	dd if=/dev/zero of=$@ bs=512 count=720
 	mformat -i $@ -t 40 -h 2 -s 9
 	mcopy -i $@ polio.com ::/
 	mcopy -i $@ polmon.com ::/
-	mcopy -i $@ mushroom.com ::/
-	mcopy -i $@ hello.com ::/
+	mcopy -i $@ $(dos-programs) ::/
 	dd if=fat12boot.bin of=$@ conv=notrunc
 
 .PHONY: clean
diff --git a/src/ftpget.c b/src/ftpget.c
index 0c70ca9..89556cf 100644
--- a/src/ftpget.c
+++ b/src/ftpget.c
@@ -19,15 +19,15 @@ int main(int argc, uint16_t argv[]) {
 
     uint8_t ok = 0x42;
 
-    for (int i = 0; i < size; i += chunksize) {
+    for (int i = 0; i < size; ) {
         runcomms(kUntilIdle);
         // delay?
 
-        uint8_t len = read(kLpt1, dest, chunksize);
-        if (len == 0) {
+        int len = read(kLpt1, dest + i, chunksize);
+        if (len <= 0) {
             break;
         }
         write(kLpt1, &ok, 1);
-        dest += len;
+        i += len;
     }
 }
diff --git a/src/stdlib.c b/src/stdlib.c
index bb319d3..eb58918 100644
--- a/src/stdlib.c
+++ b/src/stdlib.c
@@ -46,13 +46,31 @@ void* memset(void* ptr, int val, size_t len) {
     return ptr;
 }
 
+int _int80h_2(uint8_t fun, uint16_t arg1, uint16_t arg2) {
+    register uint16_t a1 asm("dx") = arg1;
+    register uint16_t a2 asm("cx") = arg2;
+    register uint8_t ah asm("ah") = fun;
+    register uint16_t ret asm("ax");
+    asm volatile("push %3            \n\t"
+                 "push %2            \n\t"
+                 "int $0x80          \n\t"
+                 "pop %%cx           \n\t"
+                 "pop %%cx           \n\t"
+                 : "=r"(ret)
+                 : "r"(ah), "r"(a1), "r"(a2)
+                 : "bx", "cc", "memory");
+
+    return ret;
+}
+
 int runcomms(char until_idle) {
     register int ret asm("ax");
     register char ui asm("al") = until_idle;
     asm volatile("mov $0x07, %%ah    \n\t"
                  "int $0x80          \n\t"
                  : "=r"(ret)
-                 : "r"(until_idle));
+                 : "r"(until_idle)
+                 : "bx", "cx", "dx", "cc", "memory");
 
     return ret;
 }
@@ -61,28 +79,12 @@ int read(int fd, void* buf, size_t size) {
     if (fd != kLpt1) {
         return -1;
     }
-    register int ret asm("ax");
-    asm volatile("push %2            \n\t"
-                 "push %1            \n\t"
-                 "mov $0x05, %%ah    \n\t"
-                 "int $0x80          \n\t"
-                 : "=r"(ret)
-                 : "r"(buf), "r"(size));
-
-    return ret;
+    return _int80h_2(0x05, (uint16_t)buf, size);
 }
 
 int write(int fd, void* buf, size_t size) {
     if (fd != kLpt1) {
         return -1;
     }
-    register int ret asm("ax");
-    asm volatile("push %2            \n\t"
-                 "push %1            \n\t"
-                 "mov $0x06, %%ah    \n\t"
-                 "int $0x80          \n\t"
-                 : "=r"(ret)
-                 : "r"(buf), "r"(size));
-
-    return ret;
+    return _int80h_2(0x06, (uint16_t)buf, size);
 }