117 lines
2.9 KiB
ArmAsm
117 lines
2.9 KiB
ArmAsm
// Program to be saved to disk
|
|
// Position independent data
|
|
// Last Modified: 1/10/2026
|
|
// Data segment pointer is R7
|
|
|
|
// Linkage to OS
|
|
.equ OS_Id,0 // returns R0 as thread ID
|
|
.equ OS_Kill,1 // kill this thread
|
|
.equ OS_Sleep,2 // R0=sleep time in ms
|
|
.equ OS_Time,3 // returns R0 as time in ms
|
|
.equ OS_AddThread,4 // R0=>code, R1=stacksize, R2=priority
|
|
.equ ST7735_Message,5 // R0=device, R1=line, R2=>string, R3=number
|
|
|
|
// Data segment, referenced from R7
|
|
.equ x,0 // 32-bit variable
|
|
.equ y,x+4 // 32-bit variable
|
|
.equ DataSize,y+4
|
|
|
|
.macro LEDToggle // flip PA0
|
|
LDR R1,GPIOA_DOUTTGL31_0
|
|
MOVS R0,#0x01
|
|
STR R0,[R1]
|
|
.endm
|
|
|
|
.text
|
|
.thumb
|
|
.align 2
|
|
.global ProgramBlock
|
|
ProgramBlock:
|
|
.long Start-ProgramBlock // offset to start
|
|
.long EndProcess-ProgramBlock // size of code segment
|
|
.long 128 // size of stack segment
|
|
.long DataSize // size of data segment
|
|
.string "Blinky" // program name
|
|
.align 2
|
|
Start:
|
|
// Assumes R7 points to data segment in RAM
|
|
MOVS R0,#1
|
|
STR R0,[R7,#x]
|
|
STR R0,[R7,#y]
|
|
BL Init
|
|
loop:
|
|
BL fun1
|
|
LDR R0,[R7,#y]
|
|
ADDS R0,#1
|
|
STR R0,[R7,#y]
|
|
LEDToggle
|
|
LDR R0,n16000000 // bus cycles
|
|
BL Delay
|
|
B loop
|
|
.align 2
|
|
n16000000: .long 16000000
|
|
.equ z,0 // local variable
|
|
fun1:
|
|
LDR R0,[R7,#y] // z=y
|
|
PUSH {R0,LR} // allocate z
|
|
l: LDR R0,[R7,#x]
|
|
ADDS R0,#1
|
|
STR R0,[R7,#x] // x++
|
|
LDR R0,[SP,#z]
|
|
SUBS R0,#1
|
|
STR R0,[SP,#z] // z--
|
|
BNE l
|
|
POP {R0,PC}
|
|
|
|
// Make PA0 an output
|
|
Init:
|
|
PUSH {LR}
|
|
LDR R0,IOMUXPA0
|
|
MOVS R1, #0x81
|
|
STR R1,[R0] //regular GPIO
|
|
LDR R0,GPIOA_DOE31_0
|
|
MOVS R4,#1 // PA0
|
|
LDR R2,[R0]
|
|
ORRS R2,R2,R4
|
|
STR R2,[R0] //enable output
|
|
POP {PC}
|
|
.align 2
|
|
GPIOA_DOE31_0: .long 0x400A12C0
|
|
GPIOA_DOUT31_0: .long 0x400A1280
|
|
GPIOA_DIN31_0: .long 0x400A1380
|
|
GPIOA_DOUTSET31_0: .long 0x400A1290
|
|
GPIOA_DOUTCLR31_0: .long 0x400A12A0
|
|
GPIOA_DOUTTGL31_0: .long 0x400A12B0
|
|
IOMUXPA0: .long 0x40428004+4*0
|
|
|
|
// input: R0 bus cycles
|
|
// output: none
|
|
Delay:
|
|
SUBS R0,R0,#2
|
|
dloop:
|
|
SUBS R0,R0,#4
|
|
NOP // C=0 on pass through 0
|
|
BHS dloop
|
|
BX LR
|
|
EndProcess:
|
|
|
|
|
|
/* unused constants
|
|
GPIOB_RSTCTL: .long 0x400A2804
|
|
GPIOB_PWREN: .long 0x400A2800
|
|
GPIOB_DOE31_0: .long 0x400A32C0
|
|
GPIOB_DOUT31_0: .long 0x400A3280
|
|
GPIOB_DOUTSET31_0: .long 0x400A3290
|
|
GPIOB_DOUTCLR31_0: .long 0x400A32A0
|
|
GPIOB_DOUTTGL31_0: .long 0x400A32B0
|
|
GPIOB_DIN31_0: .long 0x400A3380
|
|
IOMUXPA18: .long 0x40428004+4*39
|
|
IOMUXPB21: .long 0x40428004+4*48
|
|
IOMUXPB22: .long 0x40428004+4*49
|
|
IOMUXPB26: .long 0x40428004+4*56
|
|
IOMUXPB27: .long 0x40428004+4*57
|
|
n0x00060081: .long 0x00060081
|
|
n0x00050081: .long 0x00050081
|
|
*/
|
|
.end // end of file
|