efi_loader: console support for color attributes

Shell.efi uses this, and supporting color attributes makes things look
nicer.  Map the EFI fg/bg color attributes to ANSI escape sequences.
Not all colors have a perfect match, but spec just says "Devices
supporting a different number of text colors are required to emulate the
above colors to the best of the device’s capabilities".

Signed-off-by: Rob Clark <robdclark@gmail.com>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Alexander Graf <agraf@suse.de>
[agraf: s/unsigned/unsigned int/]
Signed-off-by: Alexander Graf <agraf@suse.de>

include/efi_api.h

@@ -433,6 +433,39 @@ struct simple_text_output_mode {
 	EFI_GUID(0x387477c2, 0x69c7, 0x11d2, \
 		 0x8e, 0x39, 0x0, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
 
+#define EFI_BLACK                0x00
+#define EFI_BLUE                 0x01
+#define EFI_GREEN                0x02
+#define EFI_CYAN                 0x03
+#define EFI_RED                  0x04
+#define EFI_MAGENTA              0x05
+#define EFI_BROWN                0x06
+#define EFI_LIGHTGRAY            0x07
+#define EFI_BRIGHT               0x08
+#define EFI_DARKGRAY             0x08
+#define EFI_LIGHTBLUE            0x09
+#define EFI_LIGHTGREEN           0x0a
+#define EFI_LIGHTCYAN            0x0b
+#define EFI_LIGHTRED             0x0c
+#define EFI_LIGHTMAGENTA         0x0d
+#define EFI_YELLOW               0x0e
+#define EFI_WHITE                0x0f
+#define EFI_BACKGROUND_BLACK     0x00
+#define EFI_BACKGROUND_BLUE      0x10
+#define EFI_BACKGROUND_GREEN     0x20
+#define EFI_BACKGROUND_CYAN      0x30
+#define EFI_BACKGROUND_RED       0x40
+#define EFI_BACKGROUND_MAGENTA   0x50
+#define EFI_BACKGROUND_BROWN     0x60
+#define EFI_BACKGROUND_LIGHTGRAY 0x70
+
+/* extract foreground color from EFI attribute */
+#define EFI_ATTR_FG(attr)        ((attr) & 0x07)
+/* treat high bit of FG as bright/bold (similar to edk2) */
+#define EFI_ATTR_BOLD(attr)      (((attr) >> 3) & 0x01)
+/* extract background color from EFI attribute */
+#define EFI_ATTR_BG(attr)        (((attr) >> 4) & 0x7)
+
 struct efi_simple_text_output_protocol {
 	void *reset;
 	efi_status_t (EFIAPI *output_string)(

lib/efi_loader/efi_console.c

@@ -307,14 +307,37 @@ static efi_status_t EFIAPI efi_cout_set_mode(
 	return EFI_EXIT(EFI_SUCCESS);
 }
 
+static const struct {
+	unsigned int fg;
+	unsigned int bg;
+} color[] = {
+	{ 30, 40 },     /* 0: black */
+	{ 34, 44 },     /* 1: blue */
+	{ 32, 42 },     /* 2: green */
+	{ 36, 46 },     /* 3: cyan */
+	{ 31, 41 },     /* 4: red */
+	{ 35, 45 },     /* 5: magenta */
+	{ 33, 43 },     /* 6: brown, map to yellow as edk2 does*/
+	{ 37, 47 },     /* 7: light grey, map to white */
+};
+
+/* See EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL.SetAttribute(). */
 static efi_status_t EFIAPI efi_cout_set_attribute(
 			struct efi_simple_text_output_protocol *this,
 			unsigned long attribute)
 {
+	unsigned int bold = EFI_ATTR_BOLD(attribute);
+	unsigned int fg = EFI_ATTR_FG(attribute);
+	unsigned int bg = EFI_ATTR_BG(attribute);
+
 	EFI_ENTRY("%p, %lx", this, attribute);
 
-	/* Just ignore attributes (colors) for now */
-	return EFI_EXIT(EFI_UNSUPPORTED);
+	if (attribute)
+		printf(ESC"[%u;%u;%um", bold, color[fg].fg, color[bg].bg);
+	else
+		printf(ESC"[0;37;40m");
+
+	return EFI_EXIT(EFI_SUCCESS);
 }
 
 static efi_status_t EFIAPI efi_cout_clear_screen(