function to return pointers to functions to read from a constant interface, so we only have to check the interface once per macro operation

makefile

@@ -11,6 +11,9 @@ files: out
 	cp -r src/skel/* out/fs/
 
 kernel: obj out
+	nasm src/kernel/ata.asm      -o obj/kata.o     -f elf32
+	nasm src/kernel/floppy.asm   -o obj/kfloppy.o  -f elf32
+	nasm src/kernel/ide.asm      -o obj/kide.o     -f elf32
 	nasm src/kernel/keyb.asm     -o obj/kkeyba.o   -f elf32
 	nasm src/kernel/serial.asm   -o obj/kserial.o  -f elf32
 	nasm src/kernel/stub.asm     -o obj/kstub.o    -f elf32
@@ -23,8 +26,9 @@ kernel: obj out
 	gcc  -c src/kernel/mem.c     -o obj/kmem.o     -ffreestanding -nostdlib -m32
 	gcc  -c src/kernel/proc.c    -o obj/kproc.o    -ffreestanding -nostdlib -m32
 	gcc  -c src/kernel/vga.c     -o obj/kvga.o     -ffreestanding -nostdlib -m32
-	ld obj/kkeyba.o obj/kserial.o obj/kstub.o obj/kdiskio.o obj/kfiles.o \
+	ld obj/kata.o obj/kfloppy.o obj/kide.o obj/kkeyba.o obj/kserial.o \
-		obj/kiso9660.o obj/kkeybc.o obj/kmain.o obj/kmem.o obj/kproc.o obj/kvga.o \
+	obj/kstub.o obj/kdiskio.o obj/kfiles.o obj/kiso9660.o obj/kkeybc.o \
+	obj/kmain.o obj/kmem.o obj/kproc.o obj/kvga.o \
 		-o out/kernel.elf -T src/kernel/link.ld -s --orphan-handling=discard -melf_i386
 
 clean:

src/kernel/ata.asm

@@ -0,0 +1,38 @@
+;Copyright 2019 Benji Dial
+
+;Permission to use, copy, modify, and/or distribute this
+;software for any purpose with or without fee is hereby
+;granted, provided that the above copyright notice and this
+;permission notice appear in all copies.
+
+;THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+;ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+;IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+;EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+;INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+;RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+;ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+;ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+;OF THIS SOFTWARE.
+
+global ata_read_sectors
+global ata_write_sectors
+
+section .text
+ata_read_sectors:;uint32_t ata_read_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer)
+  push ebp
+  mov ebp, esp
+
+  ;TODO
+
+  leave
+  ret
+
+ata_write_sectors:;uint32_t ata_write_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer)
+  push ebp
+  mov ebp, esp
+
+  ;TODO
+
+  leave
+  ret

src/kernel/ata.h

@@ -0,0 +1,23 @@
+/*
+Copyright 2019 Benji Dial
+
+Permission to use, copy, modify, and/or distribute this
+software for any purpose with or without fee is hereby
+granted, provided that the above copyright notice and this
+permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+OF THIS SOFTWARE.
+*/
+
+#include <stdint.h>
+
+uint32_t ata_read_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer);
+uint32_t ata_write_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer);

src/kernel/diskio.c

@@ -18,17 +18,30 @@ OF THIS SOFTWARE.
 */
 
 #include "diskio.h"
+#include "floppy.h"
+#include "ide.h"
+#include "ata.h"
 
-uint32_t read_sectors(uint8_t drive, uint32_t start, uint32_t count, void *buffer) {
+read_sectors_t read_sectors_functions[] = {
-  if ((drive >= 26) || !(drives[drive].flags & DISK_IN))
+  &floppy_read_sectors,
-    return 0;
+  &ide_read_sectors,
-  return 0;//TODO
+  &ata_read_sectors
+};
+
+read_sectors_t get_read_sectors_function(uint8_t drive) {
+  return (drive >= 26) || !(drives[drive].flags & DISK_IN) ? 0 :
+    read_sectors_functions[drives[drive].interface];
 }
 
-uint32_t write_sectors(uint8_t drive, uint32_t start, uint32_t count, void *buffer) {
+write_sectors_t write_sectors_functions[] = {
-  if ((drive >= 26) || !(drives[drive].flags & DISK_IN))
+  &floppy_write_sectors,
-    return 0;
+  &ide_write_sectors,
-  return 0;//TODO
+  &ata_write_sectors
+};
+
+write_sectors_t get_write_sectors_function(uint8_t drive) {
+  return (drive >= 26) || !(drives[drive].flags & DISK_IN) ? 0 :
+    write_sectors_functions[drives[drive].interface];
 }
 
 void update_status(uint8_t drive) {

src/kernel/diskio.h

@@ -29,6 +29,11 @@ enum interface {
   ATA
 };
 
+#define N_INTERFACES 3
+
+typedef uint32_t (*const read_sectors_t)(uint8_t, uint32_t, uint32_t, void *);
+typedef uint32_t (*const write_sectors_t)(uint8_t, uint32_t, uint32_t, void *);
+
 enum drive_flags {
   SPUN    = 0x01,
   DISK_IN = 0x02,
@@ -45,8 +50,8 @@ struct drive_info {
 
 struct drive_info drives[26];
 
-uint32_t read_sectors(uint8_t drive, uint32_t start, uint32_t count, void *buffer);
+read_sectors_t get_read_sectors_function(uint8_t drive);
-uint32_t write_sectors(uint8_t drive, uint32_t start, uint32_t count, void *buffer);
+write_sectors_t get_write_sectors_function(uint8_t drive);
 void update_status(uint8_t drive);
 
 #endif

src/kernel/floppy.asm

@@ -0,0 +1,38 @@
+;Copyright 2019 Benji Dial
+
+;Permission to use, copy, modify, and/or distribute this
+;software for any purpose with or without fee is hereby
+;granted, provided that the above copyright notice and this
+;permission notice appear in all copies.
+
+;THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+;ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+;IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+;EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+;INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+;RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+;ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+;ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+;OF THIS SOFTWARE.
+
+global floppy_read_sectors
+global floppy_write_sectors
+
+section .text
+floppy_read_sectors:;uint32_t floppy_read_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer)
+  push ebp
+  mov ebp, esp
+
+  ;TODO
+
+  leave
+  ret
+
+floppy_write_sectors:;uint32_t floppy_write_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer)
+  push ebp
+  mov ebp, esp
+
+  ;TODO
+
+  leave
+  ret

src/kernel/floppy.h

@@ -0,0 +1,23 @@
+/*
+Copyright 2019 Benji Dial
+
+Permission to use, copy, modify, and/or distribute this
+software for any purpose with or without fee is hereby
+granted, provided that the above copyright notice and this
+permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+OF THIS SOFTWARE.
+*/
+
+#include <stdint.h>
+
+uint32_t floppy_read_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer);
+uint32_t floppy_write_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer);

src/kernel/ide.asm

@@ -0,0 +1,38 @@
+;Copyright 2019 Benji Dial
+
+;Permission to use, copy, modify, and/or distribute this
+;software for any purpose with or without fee is hereby
+;granted, provided that the above copyright notice and this
+;permission notice appear in all copies.
+
+;THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+;ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+;IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+;EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+;INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+;RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+;ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+;ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+;OF THIS SOFTWARE.
+
+global ide_read_sectors
+global ide_write_sectors
+
+section .text
+ide_read_sectors:;uint32_t ide_read_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer)
+  push ebp
+  mov ebp, esp
+
+  ;TODO
+
+  leave
+  ret
+
+ide_write_sectors:;uint32_t ide_write_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer)
+  push ebp
+  mov ebp, esp
+
+  ;TODO
+
+  leave
+  ret

src/kernel/ide.h

@@ -0,0 +1,23 @@
+/*
+Copyright 2019 Benji Dial
+
+Permission to use, copy, modify, and/or distribute this
+software for any purpose with or without fee is hereby
+granted, provided that the above copyright notice and this
+permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+OF THIS SOFTWARE.
+*/
+
+#include <stdint.h>
+
+uint32_t ide_read_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer);
+uint32_t ide_write_sectors(uint8_t number, uint32_t start, uint32_t count, void *buffer);

src/kernel/iso9660.c

@@ -24,8 +24,9 @@ OF THIS SOFTWARE.
 
 bool iso_9660_parse_ph(uint8_t dn, uint8_t pn, uint32_t sector, uint8_t *buffer) {
   uint32_t s = sector + 64;
+  read_sectors_t rsf = get_read_sectors_function(dn);
   do {
-    read_sectors(dn, s, 4, buffer);
+    rsf(drives[dn].number, s, 4, buffer);
     if ((*buffer == 255) || (*(uint32_t *)&buffer[1] != 0x30304443) ||
       (buffer[5] != (uint8_t)'1'))
       return false;