Delete all references to __com32.cs_bounce

The COM32 cs_bounce buffer is not usable with ELF modules, as we're
trying to move to an environment where memory is dynamically
allocated. All users of __com32.cs_bounce have been converted to using
lmalloc() to allocate low memory.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>

4 files changed, 58 insertions, 19 deletions

diff --git a/com32/gpllib/disk/geom.c b/com32/gpllib/disk/geom.c
index 9e673ed4..e1095200 100644
--- a/com32/gpllib/disk/geom.c
+++ b/com32/gpllib/disk/geom.c
@@ -120,7 +120,7 @@ static int detect_extensions(struct driveinfo *drive_info)
 static int get_drive_parameters_with_extensions(struct driveinfo *drive_info)
 {
     com32sys_t inreg, outreg;
-    struct edd_device_parameters *dp = __com32.cs_bounce;
+    struct edd_device_parameters *dp;
 
     memset(&inreg, 0, sizeof inreg);
 
@@ -134,6 +134,10 @@ static int get_drive_parameters_with_extensions(struct driveinfo *drive_info)
      * If the buffer length is less than 26 on entry an error shall be
      * returned.
      */
+    dp = lmalloc(sizeof *dp);
+    if (!dp)
+	return -1;
+
     dp->len = sizeof(struct edd_device_parameters);
 
     inreg.esi.w[0] = OFFS(dp);
@@ -144,10 +148,13 @@ static int get_drive_parameters_with_extensions(struct driveinfo *drive_info)
     __intcall(0x13, &inreg, &outreg);
 
     /* CF set on error */
-    if (outreg.eflags.l & EFLAGS_CF)
+    if (outreg.eflags.l & EFLAGS_CF) {
+	lfree(dp);
 	return outreg.eax.b[1];
+    }
 
     memcpy(&drive_info->edd_params, dp, sizeof drive_info->edd_params);
+    lfree(dp);
 
     return 0;
 }
diff --git a/com32/gpllib/disk/read.c b/com32/gpllib/disk/read.c
index 7a6cc430..541957f9 100644
--- a/com32/gpllib/disk/read.c
+++ b/com32/gpllib/disk/read.c
@@ -76,13 +76,22 @@ int read_sectors(struct driveinfo *drive_info, void *data,
 		 const unsigned int lba, const int sectors)
 {
     com32sys_t inreg, outreg;
-    struct ebios_dapa *dapa = __com32.cs_bounce;
-    void *buf = (char *)__com32.cs_bounce + sectors * SECTOR;
+    struct ebios_dapa *dapa;
+    void *buf;
     char *bufp = data;
+    int rv = -1;
 
     if (get_drive_parameters(drive_info) == -1)
 	return -1;
 
+    buf = lmalloc(sectors * SECTOR);
+    if (!buf)
+	return -1;
+
+    dapa = lmalloc(sizeof(*dapa));
+    if (!dapa)
+	goto fail;
+
     memset(&inreg, 0, sizeof inreg);
 
     if (drive_info->ebios) {
@@ -102,7 +111,7 @@ int read_sectors(struct driveinfo *drive_info, void *data,
 	if (!drive_info->cbios) {	// XXX errno
 	    /* We failed to get the geometry */
 	    if (lba)
-		return -1;	/* Can only read MBR */
+		goto fail;	/* Can only read MBR */
 
 	    s = 1;
 	    h = 0;
@@ -112,7 +121,7 @@ int read_sectors(struct driveinfo *drive_info, void *data,
 
 	// XXX errno
 	if (s > 63 || h > 256 || c > 1023)
-	    return -1;
+	    goto fail;
 
 	inreg.eax.w[0] = 0x0201;	/* Read one sector */
 	inreg.ecx.b[1] = c & 0xff;
@@ -126,10 +135,14 @@ int read_sectors(struct driveinfo *drive_info, void *data,
     /* Perform the read */
     if (int13_retry(&inreg, &outreg)) {
 	errno_disk = outreg.eax.b[1];
-	return -1;		/* Give up */
+	goto fail;		/* Give up */
     }
 
     memcpy(bufp, buf, sectors * SECTOR);
+    rv = sectors;
 
-    return sectors;
+fail:
+    lfree(dapa);
+    lfree(buf);
+    return rv;
 }
diff --git a/com32/gpllib/disk/write.c b/com32/gpllib/disk/write.c
index 89e530d9..d183adef 100644
--- a/com32/gpllib/disk/write.c
+++ b/com32/gpllib/disk/write.c
@@ -36,8 +36,17 @@ int write_sectors(const struct driveinfo *drive_info, const unsigned int lba,
 		  const void *data, const int size)
 {
     com32sys_t inreg, outreg;
-    struct ebios_dapa *dapa = __com32.cs_bounce;
-    void *buf = (char *)__com32.cs_bounce + size;
+    struct ebios_dapa *dapa;
+    void *buf;
+    int rv = -1;
+
+    buf = lmalloc(size);
+    if (!buf)
+	return -1;
+
+    dapa = lmalloc(sizeof(*dapa));
+    if (!dapa)
+	goto out;
 
     memcpy(buf, data, size);
     memset(&inreg, 0, sizeof inreg);
@@ -59,7 +68,7 @@ int write_sectors(const struct driveinfo *drive_info, const unsigned int lba,
 	if (!drive_info->cbios) {	// XXX errno
 	    /* We failed to get the geometry */
 	    if (lba)
-		return -1;	/* Can only write MBR */
+		goto out;	/* Can only write MBR */
 
 	    s = 1;
 	    h = 0;
@@ -69,7 +78,7 @@ int write_sectors(const struct driveinfo *drive_info, const unsigned int lba,
 
 	// XXX errno
 	if (s > 63 || h > 256 || c > 1023)
-	    return -1;
+	    goto out;
 
 	inreg.eax.w[0] = 0x0301;	/* Write one sector */
 	inreg.ecx.b[1] = c & 0xff;
@@ -82,10 +91,13 @@ int write_sectors(const struct driveinfo *drive_info, const unsigned int lba,
 
     /* Perform the write */
     if (int13_retry(&inreg, &outreg)) {
-	errno_disk = outreg.eax.b[1];
-	return -1;		/* Give up */
+	errno_disk = outreg.eax.b[1];	/* Give up */
     } else
-	return size;
+	rv = size;
+out:
+    lfree(dapa);
+    lfree(buf);
+    return rv;
 }
 
 /**
diff --git a/com32/gpllib/memory.c b/com32/gpllib/memory.c
index 28a95ff4..06c746da 100644
--- a/com32/gpllib/memory.c
+++ b/com32/gpllib/memory.c
@@ -87,15 +87,20 @@ void detect_memory_e820(struct e820entry *desc, int size_map, int *size_found)
 {
     int count = 0;
     static struct e820_ext_entry buf;	/* static so it is zeroed */
+    void *bounce;
 
     com32sys_t ireg, oreg;
     memset(&ireg, 0, sizeof ireg);
 
+    bounce = lmalloc(sizeof buf);
+    if (!bounce)
+	goto out;
+
     ireg.eax.w[0] = 0xe820;
     ireg.edx.l = SMAP;
     ireg.ecx.l = sizeof(struct e820_ext_entry);
-    ireg.edi.w[0] = OFFS(__com32.cs_bounce);
-    ireg.es = SEG(__com32.cs_bounce);
+    ireg.edi.w[0] = OFFS(bounce);
+    ireg.es = SEG(bounce);
 
     /*
      * Set this here so that if the BIOS doesn't change this field
@@ -105,7 +110,7 @@ void detect_memory_e820(struct e820entry *desc, int size_map, int *size_found)
     buf.ext_flags = 1;
 
     do {
-	memcpy(__com32.cs_bounce, &buf, sizeof buf);
+	memcpy(bounce, &buf, sizeof buf);
 
 	/* Important: %edx and %esi are clobbered by some BIOSes,
 	   so they must be either used for the error output
@@ -126,7 +131,7 @@ void detect_memory_e820(struct e820entry *desc, int size_map, int *size_found)
 	if (oreg.eflags.l & EFLAGS_CF || oreg.ecx.l < 20)
 	    break;
 
-	memcpy(&buf, __com32.cs_bounce, sizeof buf);
+	memcpy(&buf, bounce, sizeof buf);
 
 	/*
 	 * ACPI 3.0 added the extended flags support.  If bit 0
@@ -143,6 +148,8 @@ void detect_memory_e820(struct e820entry *desc, int size_map, int *size_found)
 	ireg.ebx.l = oreg.ebx.l;
     } while (ireg.ebx.l && count < size_map);
 
+out:
+    lfree(bounce);
     *size_found = count;
 }