duskos

commit 46ec483232ff0280e763c43eee8cd18722e41531
parent fad50416e39be23ec087f04784c294373e7327a0
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Sun, 19 Mar 2023 09:34:40 -0400

hal: formalize API in docs

Diffstat:
M
fs/doc/hal.txt
 | 
73
+++++++++++++++++++++++++++++++++++++++++++++++++++++--------------------
M
posix/vm.c
 | 
3
+++

2 files changed, 56 insertions(+), 20 deletions(-)
diff --git a/fs/doc/hal.txt b/fs/doc/hal.txt
@@ -1,12 +1,8 @@
 # Harmonized Assembly Layer
 
-## Kernel
+TODO: description
 
-Operand structure:
-b1:0  type (0=W, 1=A, 2=PSP, 3=RSP)
-b30:2 displacement
-b31   immediate? If set, the rest of the structure is ignored and b30:0
-      represent an absolute address.
+## Low HAL
 
 Operand words:
 
@@ -14,9 +10,26 @@ W)    -- op
 A)    -- op
 PSP)  -- op
 RSP)  -- op
-i)    addr -- op
+m)    addr -- op
 +)    op disp -- op
 
+Maximum displacement in Low HAL: 8-bit
+
+Branching and conditions:
+
+Z)
+NZ)
+
+W=0>Z,
+A=0>Z,
+Z>W,
+
+execute,   a --
+branch,    a -- a
+branchC,   a cond -- a
+branch!    tgtaddr braddr --
+branchA,   --
+
 Compiler words:
 
 ps+,  n --
@@ -26,6 +39,14 @@ A+n,  n --  *Z*
 W>A,  --
 A>W,  --
 W<>A, --
+lea,  op --
+neg,  --
+cmpn, n --
+<<n,  n --
+>>n,  n --
+andn, n --
+orn,  n --
+xorn, n --
 
 Width-aware compiler words:
 
@@ -35,23 +56,35 @@ Width-aware compiler words:
 +,    op --   *Z*
 [@],  op --
 [!],  op --
+cmp,  op --
 [+n], n op -- *Z*
-lea,  op -- (width aware, but has the same behavior in all widths)
 
-Conditions
+## High HAL
+
+The "high" layer of the HAL is provided by the assembler.
+
+Operand words:
+
+i)
 
-=)
-<>)
+Branching and conditions:
+
+C)
+NC)
 <)
->)
 <=)
+>)
 >=)
-Z)
-NZ)
-C)
-NC)
+s<)
+s<=)
+s>)
+s>=)
 
-branchC, ( a cond -- a )
->branchC, ( a cond -- a ) drop and branch
-=0>Z,
-Z>W,
+Width-aware compiler words:
+
+-,    op --
+*,    op --
+/,    op --
+%,    op --
+<<,   op --
+>>,   op --
diff --git a/posix/vm.c b/posix/vm.c
@@ -9,6 +9,9 @@ b3   has disp? (type "memory" always has disp)
 b7:4 number bank id
 b8   16b?
 b9   8b?
+
+Full HAL: Unlike regular kernels, this VM contains the full HAL because it has
+no assembler to complete the HAL to "full" level later. It's all in there.
 */
 #include <inttypes.h>
 #include <stdio.h>