load Font in a non-contiguous area of memory

5 files changed, 44 insertions, 13 deletions

diff --git a/103grapheme.subx b/103grapheme.subx
index eaeacfab..abcfe57c 100644
--- a/103grapheme.subx
+++ b/103grapheme.subx
@@ -83,7 +83,7 @@ draw-grapheme-on-screen-buffer:  # buffer: (addr byte), g: grapheme, x: int, y:
     0f 8d/jump-if->= $draw-grapheme-on-screen-buffer:end/disp32
     # var letter-bitmap/esi = font[g]
     69/multiply %esi 0x21/imm32/glyph-size 6/r32/esi
-    81 0/subop/add %esi Font/imm32
+    81 0/subop/add %esi 0x0010000c/imm32/Font  # see boot.subx
     # dispatch based on letter-bitmap->size
     b8/copy-to-eax 0/imm32
     8a/byte-> *esi 0/r32/AL
@@ -116,7 +116,7 @@ wide-grapheme?:  # g: grapheme -> _/eax: boolean
     0f 8d/jump-if->= $wide-grapheme?:end/disp32
     # var letter-bitmap/eax = font[g]
     69/multiply %eax 0x21/imm32/glyph-size 0/r32/eax
-    05/add-to-eax Font/imm32
+    05/add-to-eax 0x0010000c/imm32/Font  # see boot.subx
     # dispatch based on letter-bitmap->size
     8a/byte-> *eax 0/r32/AL
     25/and-eax-with  0xff/imm32
diff --git a/boot.subx b/boot.subx
index 1cd78bfd..ed1631bc 100644
--- a/boot.subx
+++ b/boot.subx
@@ -16,6 +16,7 @@
 
 # Memory map of a Mu computer:
 #   code:         [0x00007c00, 0x0007de00)
+#   system font:  [0x00100000, 0x00f00000)
 #   stack:        (0x02000000, 0x01000000]
 #   heap:         [0x02000000, 0x80000000)
 #     see 120allocate.subx; Qemu initializes with 128MB RAM by default; simulating 2GB RAM is known to work
@@ -275,6 +276,13 @@ initialize_32bit_mode:
 
   bc/copy-to-esp 0x02000000/imm32
 
+  ## install the font somewhere non-contiguous (keep sync'd with memory map up top)
+  c7 0/subop/copy *0x00100000 0/imm32/read
+  c7 0/subop/copy *0x00100004 0/imm32/write
+  c7 0/subop/copy *0x00100008 0x00e00000/imm32/size
+  (load-sectors Primary-bus-primary-drive 0x2328 0x120 0x00100000)   # source 0x2328 = sector 9000 on disk, destination 0x00100000
+  # Font is now loaded starting at 0x0010000c.
+
   ## load interrupt handlers
   # We can't refer to the label directly because SubX doesn't do the right
   # thing for lidt, so rather than make errors worse in most places we instead
diff --git a/font.subx b/font.subx
index f7275352..dd822c71 100644
--- a/font.subx
+++ b/font.subx
@@ -11,9 +11,6 @@
 # * If it's 16, the glyph is 16 pixels wide, and each row consists of two
 #   bytes.
 
-== data
-
-Font:
 # 0x00-0x1f: unprintable ASCII
   08/size  # nul character hard-coded to 8 bits wide
   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  # nul character hard-coded to blank
diff --git a/translate b/translate
index e0e3ba02..e9fec574 100755
--- a/translate
+++ b/translate
@@ -6,7 +6,9 @@ set -e
 # Map of the Mu code disk
 export DISK=20160  # 20*16*63 512-byte sectors = almost 10MB
 dd if=/dev/zero of=code.img count=$DISK
-# code: sectors 0-10079
+# code: sectors 0-8999
+# font: sectors 9000-10079  (1080 sectors = space enough for 16k glyphs (1080 * 512 / 33 bytes per glyph))
+export FONT=9000  # keep this sync'd with boot.subx
 # debug: sector 10080 onwards
 export DEBUG=10080
 
@@ -14,7 +16,7 @@ export DEBUG=10080
 
 cat $* [0-9]*.mu                                          |linux/mu                         > a.subx
 
-cat boot.subx font.subx mu-init.subx [0-9]*.subx a.subx   |linux/braces                     > a.braces
+cat boot.subx mu-init.subx [0-9]*.subx a.subx             |linux/braces                     > a.braces
 
 cat a.braces                                              |linux/calls                      > a.calls
 
@@ -47,9 +49,9 @@ then
   exit 1
 fi
 
-if [ `stat --printf="%s" a.bin` -ge $(($DEBUG*512)) ]
+if [ `stat --printf="%s" a.bin` -ge $(($FONT*512)) ]
 then
-  echo "a.bin will overwrite debug info on disk"
+  echo "a.bin will overwrite font in disk"
   exit 1
 fi
 
@@ -68,3 +70,14 @@ then
 fi
 
 dd if=labels of=code.img seek=$DEBUG conv=notrunc  # keep this sync'd with abort.subx
+
+## Some space for font data at another well-defined location
+cat font.subx   |sed 's,#.*,,' |sed 's,/[^ ]*,,'    |linux/hex    > a.font
+
+if [ `stat --printf="%s" a.bin` -ge $(( ($DEBUG - $FONT) * 512 )) ]
+then
+  echo "font will overwrite debug info in disk"
+  exit 1
+fi
+
+dd if=a.font of=code.img seek=$FONT conv=notrunc
diff --git a/translate_emulated b/translate_emulated
index 6d3b6681..3ff4b24c 100755
--- a/translate_emulated
+++ b/translate_emulated
@@ -10,7 +10,9 @@ set -v
 # Map of the Mu code disk
 export DISK=20160  # 20*16*63 512-byte sectors = almost 10MB
 dd if=/dev/zero of=code.img count=$DISK
-# code: sectors 0-10079
+# code: sectors 0-8999
+# font: sectors 9000-10079  (1080 sectors = space enough for 16k glyphs (1080 * 512 / 33 bytes per glyph))
+export FONT=9000
 # debug: sector 10080 onwards
 export DEBUG=10080
 
@@ -18,7 +20,7 @@ export DEBUG=10080
 
 cat $* [0-9]*.mu                                          |linux/bootstrap/bootstrap run linux/mu                         > a.subx
 
-cat boot.subx font.subx mu-init.subx [0-9]*.subx a.subx   |linux/bootstrap/bootstrap run linux/braces                     > a.braces
+cat boot.subx mu-init.subx [0-9]*.subx a.subx             |linux/bootstrap/bootstrap run linux/braces                     > a.braces
 
 cat a.braces                                              |linux/bootstrap/bootstrap run linux/calls                      > a.calls
 
@@ -51,9 +53,9 @@ then
   exit 1
 fi
 
-if [ `stat --printf="%s" a.bin` -ge $(($DEBUG*512)) ]
+if [ `stat --printf="%s" a.bin` -ge $(($FONT*512)) ]
 then
-  echo "a.bin will overwrite debug info on disk"
+  echo "a.bin will overwrite font in disk"
   exit 1
 fi
 
@@ -72,3 +74,14 @@ then
 fi
 
 dd if=labels of=code.img seek=$DEBUG conv=notrunc  # keep this sync'd with abort.subx
+
+## Some space for font data at another well-defined location
+cat font.subx   |sed 's,#.*,,' |sed 's,/[^ ]*,,'    |linux/hex    > a.font
+
+if [ `stat --printf="%s" a.bin` -ge $(( ($DEBUG - $FONT) * 512 )) ]
+then
+  echo "font will overwrite debug info in disk"
+  exit 1
+fi
+
+dd if=a.font of=code.img seek=$FONT conv=notrunc