Use 32-bit registers where possible.

Saves ~180 bytes with 5-byte vs 9-byte instructions

Author: Ian Seyler

src/drivers/net/i8254x.asm

@@ -75,11 +75,11 @@ net_i8254x_init:
 	call net_i8254x_reset
 
 	; Store call addresses
-	mov rax, net_i8254x_config
+	mov eax, net_i8254x_config
 	mov [rdi+nt_config], rax
-	mov rax, net_i8254x_transmit
+	mov eax, net_i8254x_transmit
 	mov [rdi+nt_transmit], rax
-	mov rax, net_i8254x_poll
+	mov eax, net_i8254x_poll
 	mov [rdi+nt_poll], rax
 
 net_i8254x_init_error:

src/drivers/net/i8257x.asm

@@ -78,11 +78,11 @@ net_i8257x_init:
 	call net_i8257x_reset
 
 	; Store call addresses
-	mov rax, net_i8257x_config
+	mov eax, net_i8257x_config
 	mov [rdi+nt_config], rax
-	mov rax, net_i8257x_transmit
+	mov eax, net_i8257x_transmit
 	mov [rdi+nt_transmit], rax
-	mov rax, net_i8257x_poll
+	mov eax, net_i8257x_poll
 	mov [rdi+nt_poll], rax
 
 net_i8257x_init_error:

src/drivers/net/i8259x.asm

@@ -75,11 +75,11 @@ net_i8259x_init:
 	call net_i8259x_reset
 
 	; Store call addresses
-	mov rax, net_i8259x_config
+	mov eax, net_i8259x_config
 	mov [rdi+nt_config], rax
-	mov rax, net_i8259x_transmit
+	mov eax, net_i8259x_transmit
 	mov [rdi+nt_transmit], rax
-	mov rax, net_i8259x_poll
+	mov eax, net_i8259x_poll
 	mov [rdi+nt_poll], rax
 	mov eax, i8259x_MAX_DESC - 1
 	mov [rdi+nt_rx_tail], eax

src/drivers/net/virtio-net.asm

@@ -199,11 +199,11 @@ virtio_net_init_cap_end:
 
 	; Store call addresses
 	sub rdi, 0x28
-	mov rax, net_virtio_config
+	mov eax, net_virtio_config
 	stosq
-	mov rax, net_virtio_transmit
+	mov eax, net_virtio_transmit
 	stosq
-	mov rax, net_virtio_poll
+	mov eax, net_virtio_poll
 	stosq
 
 virtio_net_init_error:
@@ -452,7 +452,7 @@ net_virtio_transmit:
 
 	; Create first entry in the Descriptor Table
 	mov rdi, r8
-	mov rax, virtio_net_hdr		; Address of the 12-byte virtio_net_hdr
+	mov eax, virtio_net_hdr		; Address of the 12-byte virtio_net_hdr
 	stosq				; 64-bit address
 	mov eax, 12
 	stosd				; 32-bit length

src/drivers/nvs/ahci.asm

@@ -176,9 +176,9 @@ ahci_init_search_ports_done:
 ahci_init_done:
 	bts word [os_nvsVar], 1	; Set the bit flag that AHCI has been initialized
 	mov rdi, os_nvs_io
-	mov rax, ahci_io
+	mov eax, ahci_io
 	stosq
-	mov rax, ahci_id
+	mov eax, ahci_id
 	stosq
 	pop rdx
 	pop rsi

src/drivers/nvs/nvme.asm

@@ -174,9 +174,9 @@ nvme_init_LBA_end:
 nvme_init_done:
 	bts word [os_nvsVar], 0	; Set the bit flag that NVMe has been initialized
 	mov rdi, os_nvs_io
-	mov rax, nvme_io
+	mov eax, nvme_io
 	stosq
-	mov rax, nvme_id
+	mov eax, nvme_id
 	stosq
 	pop rdx
 	pop rsi
@@ -352,13 +352,13 @@ nvme_io_next_rpr:
 	stosq
 	sub rcx, 1
 	cmp rcx, 0
-	jne nvme_io_next_rpr	
+	jne nvme_io_next_rpr
 	pop rdi
 	mov rax, os_nvme_rpr
 	jmp nvme_io_calc_rpr2_end	; Write the address of the RPR2 data
 nvme_io_calc_rpr2_skip:
 	add rax, 4096
-nvme_io_calc_rpr2_end:	
+nvme_io_calc_rpr2_end:
 	stosq				; CDW8-9 PRP2
 	pop rcx				; Restore the sector count
 
@@ -463,7 +463,7 @@ NVMe_PMRCAP	equ 0xE00	; 4-byte Persistent Memory Region Capabilities
 NVMe_PMRCTL	equ 0xE04	; 4-byte Persistent Memory Region Control
 NVMe_PMRSTS	equ 0xE08	; 4-byte Persistent Memory Region Status
 NVMe_PMREBS	equ 0xE0C	; 4-byte Persistent Memory Region Elasticity Buffer Size
-NVMe_PMRSWTP	equ 0xE10	; 4-byte Persistent Memory Region Sustained Write Throughput 
+NVMe_PMRSWTP	equ 0xE10	; 4-byte Persistent Memory Region Sustained Write Throughput
 NVMe_PMRMSCL	equ 0xE14	; 4-byte Persistent Memory Region Memory Space Control Lower
 NVMe_PMRMSCU	equ 0xE18	; 4-byte Persistent Memory Region Memory Space Control Upper
 

src/drivers/nvs/virtio-blk.asm

@@ -105,7 +105,7 @@ virtio_blk_init_cap_end:
 	; Device Initialization (section 3.1)
 
 	; 3.1.1 - Step 1 -  Reset the device (section 2.4)
-	mov al, 0x00			
+	mov al, 0x00
 	mov [rsi+VIRTIO_DEVICE_STATUS], al
 virtio_blk_init_reset_wait:
 	mov al, [rsi+VIRTIO_DEVICE_STATUS]
@@ -202,9 +202,9 @@ virtio_blk_init_pop:
 virtio_blk_init_done:
 	bts word [os_nvsVar], 3	; Set the bit flag that Virtio Block has been initialized
 	mov rdi, os_nvs_io		; Write over the storage function addresses
-	mov rax, virtio_blk_io
+	mov eax, virtio_blk_io
 	stosq
-	mov rax, virtio_blk_id
+	mov eax, virtio_blk_id
 	stosq
 	pop rax
 	pop rbx
@@ -248,7 +248,7 @@ virtio_blk_io:
 					; FIXME: Add desc_index offset
 
 	; Add header to Descriptor Entry 0
-	mov rax, header			; Address of the header
+	mov eax, header			; Address of the header
 	stosq				; 64-bit address
 	mov eax, 16
 	stosd				; 32-bit length
@@ -267,7 +267,7 @@ virtio_blk_io:
 	add rdi, 2			; Skip Next as it is pre-populated
 
 	; Add footer to Descriptor Entry 3
-	mov rax, footer			; Address of the footer
+	mov eax, footer			; Address of the footer
 	stosq				; 64-bit address
 	mov eax, 1
 	stosd				; 32-bit length
@@ -276,7 +276,7 @@ virtio_blk_io:
 	add rdi, 2			; Skip Next as it is pre-populated
 
 	; Build the header
-	mov rdi, header
+	mov edi, header
 	; BareMetal I/O opcode for Read is 2, Write is 1
 	; Virtio-blk I/O opcode for Read is 0, Write is 1
 	; FIXME: Currently we just clear bit 1.
@@ -290,7 +290,7 @@ virtio_blk_io:
 	stosq				; starting sector
 
 	; Build the footer
-	mov rdi, footer
+	mov edi, footer
 	xor eax, eax
 	stosb
 
@@ -331,7 +331,7 @@ virtio_blk_io_wait:
 
 
 ; -----------------------------------------------------------------------------
-; virtio_blk_id -- 
+; virtio_blk_id --
 ; IN:	EAX = CDW0
 ;	EBX = CDW1
 ;	ECX = CDW10
@@ -380,15 +380,15 @@ VIRTIO_BLK_MIN_IO_SIZE				equ 0x2E ; 16-bit SUGGESTED MINIMUM I/O SIZE IN BLOCKS
 VIRTIO_BLK_OPT_IO_SIZE				equ 0x30 ; 32-bit OPTIMAL (SUGGESTED MAXIMUM) I/O SIZE IN BLOCKS
 VIRTIO_BLK_WRITEBACK				equ 0x34 ; 8-bit
 VIRTIO_BLK_NUM_QUEUES				equ 0x36 ; 16-bit
-VIRTIO_BLK_MAX_DISCARD_SECTORS			equ 0x38 ; 32-bit 
-VIRTIO_BLK_MAX_DISCARD_SEG			equ 0x3C ; 32-bit 
-VIRTIO_BLK_DISCARD_SECTOR_ALIGNMENT		equ 0x40 ; 32-bit 
-VIRTIO_BLK_MAX_WRITE_ZEROES_SECTORS		equ 0x44 ; 32-bit 
-VIRTIO_BLK_MAX_WRITE_ZEROES_SEG			equ 0x48 ; 32-bit 
+VIRTIO_BLK_MAX_DISCARD_SECTORS			equ 0x38 ; 32-bit
+VIRTIO_BLK_MAX_DISCARD_SEG			equ 0x3C ; 32-bit
+VIRTIO_BLK_DISCARD_SECTOR_ALIGNMENT		equ 0x40 ; 32-bit
+VIRTIO_BLK_MAX_WRITE_ZEROES_SECTORS		equ 0x44 ; 32-bit
+VIRTIO_BLK_MAX_WRITE_ZEROES_SEG			equ 0x48 ; 32-bit
 VIRTIO_BLK_WRITE_ZEROES_MAY_UNMAP		equ 0x4C ; 8-bit
-VIRTIO_BLK_MAX_SECURE_ERASE_SECTORS		equ 0x50 ; 32-bit 
-VIRTIO_BLK_MAX_SECURE_ERASE_SEG			equ 0x54 ; 32-bit 
-VIRTIO_BLK_SECURE_ERASE_SECTOR_ALIGNMENT	equ 0x58 ; 32-bit 
+VIRTIO_BLK_MAX_SECURE_ERASE_SECTORS		equ 0x50 ; 32-bit
+VIRTIO_BLK_MAX_SECURE_ERASE_SEG			equ 0x54 ; 32-bit
+VIRTIO_BLK_SECURE_ERASE_SECTOR_ALIGNMENT	equ 0x58 ; 32-bit
 
 ; VIRTIO_DEVICEFEATURES bits
 VIRTIO_BLK_F_BARRIER			equ 0 ; Legacy - Device supports request barriers

src/drivers/ps2.asm

@@ -68,7 +68,7 @@ ps2_init:
 	bt ebx, 0
 	jnc init_64_no_ps2keyboard
 	mov edi, 0x21
-	mov rax, int_keyboard
+	mov eax, int_keyboard
 	call create_gate
 	; Enable specific interrupt
 	mov ecx, 1			; Keyboard IRQ
@@ -121,11 +121,11 @@ keydown:
 	je keyboard_lowercase
 
 keyboard_uppercase:
-	mov rbx, keylayoutupper
+	mov ebx, keylayoutupper
 	jmp keyboard_processkey
 
 keyboard_lowercase:
-	mov rbx, keylayoutlower
+	mov ebx, keylayoutlower
 
 keyboard_processkey:			; Convert the scan code
 	add rbx, rax

src/drivers/serial.asm

@@ -27,7 +27,7 @@ serial_init_skip_arch:
 %ifdef NO_LFB
 	; Configure interrupt handler
 	mov edi, 0x24
-	mov rax, int_serial
+	mov eax, int_serial
 	call create_gate
 
 	; Enable specific interrupts
@@ -41,7 +41,7 @@ serial_init_skip_arch:
 	out dx, al
 %endif
 
-	mov rax, b_output_serial
+	mov eax, b_output_serial
 	mov [0x100018], rax		; Set kernel b_output to the serial port
 
 serial_init_error:

src/drivers/vga.asm

@@ -22,10 +22,10 @@ vga_init:
 	mov dx, 0x03C8			; DAC Address Write Mode Register
 	out dx, al
 	mov dx, 0x03C9			; DAC Data Register
-	mov rbx, 16			; 16 lines
+	mov ebx, 16			; 16 lines
 nextlineq:
-	mov rcx, 16			; 16 colors
-	mov rsi, palette
+	mov ecx, 16			; 16 colors
+	mov esi, palette
 nexttritone:
 	lodsb
 	out dx, al
@@ -43,16 +43,16 @@ nexttritone:
 	mov dx, 0x03C8			; DAC Address Write Mode Register
 	out dx, al
 	mov dx, 0x03C9			; DAC Data Register
-	mov rsi, palette
-	add rsi, 18
+	mov esi, palette
+	add esi, 18
 	lodsb
 	out dx, al
 	lodsb
 	out dx, al
 	lodsb
 	out dx, al
 
-	mov rax, vga_output_chars
+	mov eax, vga_output_chars
 	mov [0x100018], rax
 
 	ret