git: 017912879876 - stable/12 - Use symbolic names for int13 calls

The branch stable/12 has been updated by kevans:

URL: https://cgit.FreeBSD.org/src/commit/?id=01791287987664b5db4a362dc817f7081553aca2

commit 01791287987664b5db4a362dc817f7081553aca2
Author:     Warner Losh <imp@FreeBSD.org>
AuthorDate: 2019-12-16 21:52:12 +0000
Commit:     Kyle Evans <kevans@FreeBSD.org>
CommitDate: 2021-10-08 01:15:58 +0000

    Use symbolic names for int13 calls
    
    For all the INT13 calls, use symbolic names instead of magic numbers. This makes
    it easier to understand what the code is doing w/o a trip to google to find what
    these numbers mean.
    
    (cherry picked from commit 7f5499972e115cafc861ec438cd7237422cd9b7c)
---
 stand/i386/common/edd.h       |  3 ++
 stand/i386/libi386/biosdisk.c | 65 ++++++++++++++++++++++++++-----------------
 2 files changed, 43 insertions(+), 25 deletions(-)

diff --git a/stand/i386/common/edd.h b/stand/i386/common/edd.h
index 7d1f45020f9d..9739c45b0f38 100644
--- a/stand/i386/common/edd.h
+++ b/stand/i386/common/edd.h
@@ -107,4 +107,7 @@ struct edd_params_v4 {
 
 #define	EDD_DEVICE_PATH_KEY	0xbedd
 
+#define	EDD_QUERY_MAGIC		0x55aa
+#define	EDD_INSTALLED		0xaa55
+
 #endif /* !_EDD_H_ */
diff --git a/stand/i386/libi386/biosdisk.c b/stand/i386/libi386/biosdisk.c
index c2d95e81161f..00d2de5de418 100644
--- a/stand/i386/libi386/biosdisk.c
+++ b/stand/i386/libi386/biosdisk.c
@@ -64,6 +64,22 @@ __FBSDID("$FreeBSD$");
 #define	ACDMAJOR	117
 #define	CDMAJOR		15
 
+/*
+ * INT13 commands
+ */
+#define	CMD_RESET	0x0000
+#define	CMD_READ_CHS	0x0200
+#define	CMD_WRITE_CHS	0x0300
+#define	CMD_READ_PARAM	0x0800
+#define	CMD_DRIVE_TYPE	0x1500
+#define	CMD_CHECK_EDD	0x4100
+#define	CMD_READ_LBA	0x4200
+#define	CMD_WRITE_LBA	0x4300
+#define	CMD_EXT_PARAM	0x4800
+#define	CMD_CD_GET_STATUS 0x4b01
+
+#define	DISK_BIOS	0x13
+
 #ifdef DISK_DEBUG
 #define	DPRINTF(fmt, args...)	printf("%s: " fmt "\n", __func__, ## args)
 #else
@@ -266,8 +282,8 @@ fd_count(void)
 		bd_reset_disk(drive);
 
 		v86.ctl = V86_FLAGS;
-		v86.addr = 0x13;
-		v86.eax = 0x1500;
+		v86.addr = DISK_BIOS;
+		v86.eax = CMD_DRIVE_TYPE;
 		v86.edx = drive;
 		v86int();
 
@@ -371,8 +387,8 @@ bd_get_diskinfo_cd(struct bdinfo *bd)
 	bc_sp.sp_size = sizeof (bc_sp) - sizeof (bc_sp.sp_dummy);
 
         v86.ctl = V86_FLAGS;
-        v86.addr = 0x13;
-        v86.eax = 0x4b01;
+        v86.addr = DISK_BIOS;
+        v86.eax = CMD_CD_GET_STATUS;
         v86.edx = bd->bd_unit;
         v86.ds = VTOPSEG(&bc_sp);
         v86.esi = VTOPOFF(&bc_sp);
@@ -462,14 +478,14 @@ bd_check_extensions(int unit)
 
 	/* Determine if we can use EDD with this device. */
 	v86.ctl = V86_FLAGS;
-	v86.addr = 0x13;
-	v86.eax = 0x4100;
+	v86.addr = DISK_BIOS;
+	v86.eax = CMD_CHECK_EDD;
 	v86.edx = unit;
-	v86.ebx = 0x55aa;
+	v86.ebx = EDD_QUERY_MAGIC;
 	v86int();
 
 	if (V86_CY(v86.efl) ||			/* carry set */
-	    (v86.ebx & 0xffff) != 0xaa55)	/* signature */
+	    (v86.ebx & 0xffff) != EDD_INSTALLED) /* signature */
 		return (0);
 
 	/* extended disk access functions (AH=42h-44h,47h,48h) supported */
@@ -484,8 +500,8 @@ bd_reset_disk(int unit)
 {
 	/* reset disk */
 	v86.ctl = V86_FLAGS;
-	v86.addr = 0x13;
-	v86.eax = 0;
+	v86.addr = DISK_BIOS;
+	v86.eax = CMD_RESET;
 	v86.edx = unit;
 	v86int();
 }
@@ -498,8 +514,8 @@ bd_get_diskinfo_std(struct bdinfo *bd)
 {
 	bzero(&v86, sizeof(v86));
 	v86.ctl = V86_FLAGS;
-	v86.addr = 0x13;
-	v86.eax = 0x800;
+	v86.addr = DISK_BIOS;
+	v86.eax = CMD_READ_PARAM;
 	v86.edx = bd->bd_unit;
 	v86int();
 
@@ -543,8 +559,8 @@ bd_get_diskinfo_ext(struct bdinfo *bd)
 	bzero(&dparams, sizeof(dparams));
 	params->len = sizeof(struct edd_params_v3);
 	v86.ctl = V86_FLAGS;
-	v86.addr = 0x13;
-	v86.eax = 0x4800;
+	v86.addr = DISK_BIOS;
+	v86.eax = CMD_EXT_PARAM;
 	v86.edx = bd->bd_unit;
 	v86.ds = VTOPSEG(&dparams);
 	v86.esi = VTOPOFF(&dparams);
@@ -615,8 +631,8 @@ bd_int13probe(bdinfo_t *bd)
 
 		/* Get disk type */
 		v86.ctl = V86_FLAGS;
-		v86.addr = 0x13;
-		v86.eax = 0x1500;
+		v86.addr = DISK_BIOS;
+		v86.eax = CMD_DRIVE_TYPE;
 		v86.edx = bd->bd_unit;
 		v86int();
 		if (V86_CY(v86.efl) || (v86.eax & 0x300) == 0)
@@ -1125,12 +1141,11 @@ bd_edd_io(bdinfo_t *bd, daddr_t dblk, int blks, caddr_t dest,
 	packet.seg = VTOPSEG(dest);
 	packet.lba = dblk;
 	v86.ctl = V86_FLAGS;
-	v86.addr = 0x13;
-	/* Should we Write with verify ?? 0x4302 ? */
+	v86.addr = DISK_BIOS;
 	if (dowrite == BD_WR)
-		v86.eax = 0x4300;
+		v86.eax = CMD_WRITE_LBA; /* maybe Write with verify 0x4302? */
 	else
-		v86.eax = 0x4200;
+		v86.eax = CMD_READ_LBA;
 	v86.edx = bd->bd_unit;
 	v86.ds = VTOPSEG(&packet);
 	v86.esi = VTOPOFF(&packet);
@@ -1162,11 +1177,11 @@ bd_chs_io(bdinfo_t *bd, daddr_t dblk, int blks, caddr_t dest,
 	}
 
 	v86.ctl = V86_FLAGS;
-	v86.addr = 0x13;
+	v86.addr = DISK_BIOS;
 	if (dowrite == BD_WR)
-		v86.eax = 0x300 | blks;
+		v86.eax = CMD_WRITE_CHS | blks;
 	else
-		v86.eax = 0x200 | blks;
+		v86.eax = CMD_READ_CHS | blks;
 	v86.ecx = ((cyl & 0xff) << 8) | ((cyl & 0x300) >> 2) | sec;
 	v86.edx = (hd << 8) | bd->bd_unit;
 	v86.es = VTOPSEG(dest);
@@ -1271,8 +1286,8 @@ bd_getbigeom(int bunit)
 {
 
 	v86.ctl = V86_FLAGS;
-	v86.addr = 0x13;
-	v86.eax = 0x800;
+	v86.addr = DISK_BIOS;
+	v86.eax = CMD_READ_PARAM;
 	v86.edx = 0x80 + bunit;
 	v86int();
 	if (V86_CY(v86.efl))