My MacBook has UGA only, but we fail to detect any changes

in the frame buffer when we flip pixels. Allow the detection
to be bypassed by setting the uga_framebuffer and uga_stride
variables. The kernel console works fine even when we can't
detect pixel changes in the frame buffer, which indicates
that the problem could be with reading from the frame buffer
and not writing to it.

1 files changed, 50 insertions, 24 deletions

diff --git a/sys/boot/efi/loader/arch/amd64/framebuffer.c b/sys/boot/efi/loader/arch/amd64/framebuffer.c
index 25262ef..7a2e56b6 100644
--- a/sys/boot/efi/loader/arch/amd64/framebuffer.c
+++ b/sys/boot/efi/loader/arch/amd64/framebuffer.c
@@ -183,29 +183,24 @@ efifb_uga_find_pixel(EFI_UGA_DRAW_PROTOCOL *uga, u_int line,
 	return (-1);
 }
 
-static EFI_STATUS
-efifb_uga_detect_framebuffer(EFI_UGA_DRAW_PROTOCOL *uga,
-    EFI_PCI_IO_PROTOCOL **pciiop, uint64_t *addrp, uint64_t *sizep)
+static EFI_PCI_IO_PROTOCOL *
+efifb_uga_get_pciio(void)
 {
 	EFI_PCI_IO_PROTOCOL *pciio;
 	EFI_HANDLE *buf, *hp;
-	uint8_t *resattr;
-	uint64_t a, addr, s, size;
-	ssize_t ofs;
 	EFI_STATUS status;
 	UINTN bufsz;
-	u_int bar;
 
 	/* Get all handles that support the UGA protocol. */
 	bufsz = 0;
 	status = BS->LocateHandle(ByProtocol, &uga_guid, NULL, &bufsz, NULL);
 	if (status != EFI_BUFFER_TOO_SMALL)
-		return (status);
+		return (NULL);
 	buf = malloc(bufsz);
 	status = BS->LocateHandle(ByProtocol, &uga_guid, NULL, &bufsz, buf);
 	if (status != EFI_SUCCESS) {
 		free(buf);
-		return (status);
+		return (NULL);
 	}
 	bufsz /= sizeof(EFI_HANDLE);
 
@@ -213,12 +208,24 @@ efifb_uga_detect_framebuffer(EFI_UGA_DRAW_PROTOCOL *uga,
 	pciio = NULL;
 	for (hp = buf; hp < buf + bufsz; hp++) {
 		status = BS->HandleProtocol(*hp, &pciio_guid, (void **)&pciio);
-		if (status == EFI_SUCCESS)
-			break;
+		if (status == EFI_SUCCESS) {
+			free(buf);
+			return (pciio);
+		}
 	}
 	free(buf);
-	if (status != EFI_SUCCESS || pciio == NULL)
-		return (EFI_NOT_FOUND);
+	return (NULL);
+}
+
+static EFI_STATUS
+efifb_uga_detect_framebuffer(EFI_UGA_DRAW_PROTOCOL *uga,
+    EFI_PCI_IO_PROTOCOL *pciio, uint64_t *addrp, uint64_t *sizep)
+{
+	uint8_t *resattr;
+	uint64_t a, addr, s, size;
+	ssize_t ofs;
+	EFI_STATUS status;
+	u_int bar;
 
 	/* Attempt to get the frame buffer address (imprecise). */
 	addr = 0;
@@ -265,7 +272,6 @@ efifb_uga_detect_framebuffer(EFI_UGA_DRAW_PROTOCOL *uga,
 	addr += ofs;
 	size -= ofs;
 
-	*pciiop = pciio;
 	*addrp = addr;
 	*sizep = size;
 	return (0);
@@ -275,6 +281,7 @@ static int
 efifb_from_uga(struct efi_fb *efifb, EFI_UGA_DRAW_PROTOCOL *uga)
 {
 	EFI_PCI_IO_PROTOCOL *pciio;
+	char *ev, *p;
 	EFI_STATUS status;
 	ssize_t ofs;
 	uint32_t horiz, vert, depth, refresh;
@@ -287,18 +294,37 @@ efifb_from_uga(struct efi_fb *efifb, EFI_UGA_DRAW_PROTOCOL *uga)
 	efifb_mask_from_pixfmt(efifb, PixelBlueGreenRedReserved8BitPerColor,
 	    NULL);
 
-	/* Try and find the frame buffer. */
-	status = efifb_uga_detect_framebuffer(uga, &pciio, &efifb->fb_addr,
-	    &efifb->fb_size);
-	if (EFI_ERROR(status))
+	pciio = efifb_uga_get_pciio();
+	if (pciio == NULL)
 		return (1);
 
-	/* Try and detect the stride. */
-	ofs = efifb_uga_find_pixel(uga, 1, pciio, efifb->fb_addr,
-	    efifb->fb_size);
-	if (ofs == -1)
-		return (1);
-	efifb->fb_stride = ofs >> 2;
+	ev = getenv("uga_framebuffer");
+	if (ev == NULL) {
+		/* Try to find the frame buffer. */
+		status = efifb_uga_detect_framebuffer(uga, pciio,
+		    &efifb->fb_addr, &efifb->fb_size);
+		if (EFI_ERROR(status))
+			return (1);
+	} else {
+		efifb->fb_size = horiz * vert * 4;
+		efifb->fb_addr = strtoul(ev, &p, 0);
+		if (*p != '\0')
+			return (1);
+	}
+
+	ev = getenv("uga_stride");
+	if (ev == NULL) {
+		/* Try to detect the stride. */
+		ofs = efifb_uga_find_pixel(uga, 1, pciio, efifb->fb_addr,
+		    efifb->fb_size);
+		if (ofs == -1)
+			return (1);
+		efifb->fb_stride = ofs >> 2;
+	} else {
+		efifb->fb_stride = strtoul(ev, &p, 0);
+		if (*p != '\0')
+			return (1);
+	}
 	return (0);
 }