Skip to content

Fix assembly bugs in EMS integration tests #1449

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
maximilien-noal merged 2 commits into from
Oct 29, 2025
Merged

Fix assembly bugs in EMS integration tests #1449

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
f3208c3
Initial plan
Copilot Oct 29, 2025
03e6dc5
Fix EMS integration test assembly bugs - all 17 tests now pass
Copilot Oct 29, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
25 changes: 14 additions & 11 deletions tests/Spice86.Tests/Dos/Ems/EmsIntegrationTests.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -63,9 +63,12 @@ public void EmsDetection_ViaDeviceDriverName_ShouldFindEMMXXXX0() {
// This test verifies the second detection method:
// Opening the "EMMXXXX0" device and checking its presence
byte[] program = new byte[] {
// Set DS to CS so we can access the device name
0x0E, // push cs
0x1F, // pop ds
// Try to open EMMXXXX0 device
0xB8, 0x00, 0x3D, // mov ax, 3D00h - Open file for reading
0xBA, 0x20, 0x00, // mov dx, 0x0020 - Offset to device name
0xBA, 0x1E, 0x01, // mov dx, 0x011E - Offset to device name (0x100 + 0x1E)
0xCD, 0x21, // int 21h
0x72, 0x06, // jc openFailed - Jump if carry (error)
// Success - close the handle
Expand All @@ -80,7 +83,7 @@ public void EmsDetection_ViaDeviceDriverName_ShouldFindEMMXXXX0() {
0xBA, 0x99, 0x09, // mov dx, ResultPort
0xEE, // out dx, al
0xF4, // hlt
// Device name at offset 0x20:
// Device name at offset 0x1E from start (0x100 + 0x1E = 0x11E absolute):
0x45, 0x4D, 0x4D, 0x58, 0x58, 0x58, 0x58, 0x30, 0x00 // "EMMXXXX0\0"
};

Expand Down Expand Up @@ -257,7 +260,7 @@ public void EmsMemoryAccess_ThroughMappedPages_ShouldWork() {
0xB4, 0x43, // mov ah, 43h
0xCD, 0x67, // int 67h
0x80, 0xFC, 0x00, // cmp ah, 0
0x75, 0x25, // jne failed
0x75, 0x26, // jne failed (was 0x25, +1 for extra byte in write)
0x89, 0xD1, // mov cx, dx - Save handle
// Map logical page 0 to physical page 0
0xB0, 0x00, // mov al, 0
Expand All @@ -266,11 +269,11 @@ public void EmsMemoryAccess_ThroughMappedPages_ShouldWork() {
0xB4, 0x44, // mov ah, 44h
0xCD, 0x67, // int 67h
0x80, 0xFC, 0x00, // cmp ah, 0
0x75, 0x16, // jne failed
0x75, 0x17, // jne failed (was 0x16, +1 for extra byte in write)
// Write test value to EMS page at E000:0000
0xB8, 0x00, 0xE0, // mov ax, 0xE000
0x8E, 0xC0, // mov es, ax
0xC6, 0x06, 0x00, 0x00, 0x42, // mov byte [es:0], 42h
0x26, 0xC6, 0x06, 0x00, 0x00, 0x42, // mov byte [es:0], 42h
// Read back and verify
0x26, 0xA0, 0x00, 0x00, // mov al, [es:0]
0x3C, 0x42, // cmp al, 42h
Expand Down Expand Up @@ -548,7 +551,7 @@ public void EmsLogicalPages_ShouldBeIndependent() {
0xB4, 0x43, // mov ah, 43h
0xCD, 0x67, // int 67h
0x80, 0xFC, 0x00, // cmp ah, 0
0x75, 0x4C, // jne failed
0x75, 0x4E, // jne failed (was 0x4C, +2 for two extra bytes in writes)
0x89, 0xD1, // mov cx, dx - Save handle
// Map logical page 0 to physical page 0
0xB0, 0x00, // mov al, 0
Expand All @@ -557,29 +560,29 @@ public void EmsLogicalPages_ShouldBeIndependent() {
0xB4, 0x44, // mov ah, 44h
0xCD, 0x67, // int 67h
0x80, 0xFC, 0x00, // cmp ah, 0
0x75, 0x3D, // jne failed
0x75, 0x3F, // jne failed (was 0x3D, +2 for two extra bytes in writes)
// Write 11h to first byte of logical page 0
0xB8, 0x00, 0xE0, // mov ax, 0xE000
0x8E, 0xC0, // mov es, ax
0xC6, 0x06, 0x00, 0x00, 0x11, // mov byte [es:0], 11h
0x26, 0xC6, 0x06, 0x00, 0x00, 0x11, // mov byte [es:0], 11h
// Map logical page 1 to physical page 0
0xB0, 0x00, // mov al, 0
0xBB, 0x01, 0x00, // mov bx, 1
0x89, 0xCA, // mov dx, cx
0xB4, 0x44, // mov ah, 44h
0xCD, 0x67, // int 67h
0x80, 0xFC, 0x00, // cmp ah, 0
0x75, 0x26, // jne failed
0x75, 0x28, // jne failed (was 0x26, +2 for two extra bytes in writes)
// Write 22h to first byte of logical page 1
0xC6, 0x06, 0x00, 0x00, 0x22, // mov byte [es:0], 22h
0x26, 0xC6, 0x06, 0x00, 0x00, 0x22, // mov byte [es:0], 22h
// Map logical page 0 back to physical page 0
0xB0, 0x00, // mov al, 0
0xBB, 0x00, 0x00, // mov bx, 0
0x89, 0xCA, // mov dx, cx
0xB4, 0x44, // mov ah, 44h
0xCD, 0x67, // int 67h
0x80, 0xFC, 0x00, // cmp ah, 0
0x75, 0x0F, // jne failed
0x75, 0x0F, // jne failed (unchanged, no extra bytes after this point)
// Verify logical page 0 still has 11h
0x26, 0xA0, 0x00, 0x00, // mov al, [es:0]
0x3C, 0x11, // cmp al, 11h
Expand Down
Loading