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-rw-r--r--octedit/Makefile4
-rw-r--r--octedit/crc.s6
-rw-r--r--octedit/main.s18
-rw-r--r--octedit/octedit.s45
-rw-r--r--octedit/pico_persist.ld5
-rw-r--r--octedit/setup.s94
-rw-r--r--octedit/uart.s4
7 files changed, 141 insertions, 35 deletions
diff --git a/octedit/Makefile b/octedit/Makefile
index 26601c8..4603ef4 100644
--- a/octedit/Makefile
+++ b/octedit/Makefile
@@ -5,10 +5,10 @@ build: octedit.uf2
octedit.uf2: octedit.elf
../elf/elf2uf2 octedit.elf octedit.uf2
-objects = uart.o main.o octedit.o
+objects = setup.o octedit.o uart.o crc.o
octedit.elf: $(objects)
- arm-none-eabi-ld -T pico_persist.ld -o octedit.elf $(objects) ../setup/setup.so
+ arm-none-eabi-ld -T pico_persist.ld -o octedit.elf $(objects)
./checksum_pico_elf.py octedit.elf
$(objects): %.o: %.s
diff --git a/octedit/crc.s b/octedit/crc.s
new file mode 100644
index 0000000..8019c6d
--- /dev/null
+++ b/octedit/crc.s
@@ -0,0 +1,6 @@
+.syntax unified
+.cpu cortex-m0plus
+.thumb
+
+.section .stage_2_crc
+.word 0x00000000
diff --git a/octedit/main.s b/octedit/main.s
deleted file mode 100644
index 6c471ec..0000000
--- a/octedit/main.s
+++ /dev/null
@@ -1,18 +0,0 @@
-.syntax unified
-.cpu cortex-m0plus
-.thumb
-
-.section .entry, "ax"
-
-.type main, %function
-.global main
-
-main:
- bl start_xosc
- bl setup_clocks
- bl setup_gpio
- bl setup_uart
- b octedit
-
-.section .stage_2_crc
-.word 0x00000000
diff --git a/octedit/octedit.s b/octedit/octedit.s
index 9445fd8..7d9e7f4 100644
--- a/octedit/octedit.s
+++ b/octedit/octedit.s
@@ -11,24 +11,47 @@ octedit:
ldr r6, =SRAM_BASE
adds r5, r6, 1
10:
- movs r4, 0
+ movs r4, 11
+ movs r0, 0x1E
+ rors r6, r0
+ movs r0, 0x01
+ b 1f
+0:
+ movs r0, 0x1D
+ rors r6, r0
+ movs r0, 0x07
+1:
+ ands r0, r6
+ adds r0, 0x30
+ bl uart_send
+ subs r4, 1
+ bne 0b
+ movs r0, '
+ bl uart_send
20:
bl uart_recv
cmp r0, '\r
- beq 30f
- cmp r0, 'G
- beq 40f
- bl uart_send
- subs r0, '0
- lsls r4, 3
- adds r4, r0
- b 20b
-30:
+ bne 30f
bl uart_send
movs r0, '\n
bl uart_send
strh r4, [r6]
adds r6, 2
b 10b
-40:
+30:
+ cmp r0, 'G
+ bne 40f
bx r5
+40:
+ cmp r0, 'B
+ bne 50f
+ movs r0, '\r
+ bl uart_send
+ subs r6, 2
+ b 10b
+50:
+ bl uart_send
+ subs r0, '0
+ lsls r4, 3
+ adds r4, r0
+ b 20b
diff --git a/octedit/pico_persist.ld b/octedit/pico_persist.ld
index 9c37aba..fd9cf67 100644
--- a/octedit/pico_persist.ld
+++ b/octedit/pico_persist.ld
@@ -5,8 +5,9 @@ MEMORY {
SECTIONS {
.text : {
- *(.entry);
- *(.text);
+ setup.o(.text);
+ octedit.o(.text);
+ uart.o(.text);
. = 252;
*(.stage_2_crc);
} >SRAM AT>FLASH
diff --git a/octedit/setup.s b/octedit/setup.s
new file mode 100644
index 0000000..378b54e
--- /dev/null
+++ b/octedit/setup.s
@@ -0,0 +1,94 @@
+.syntax unified
+.cpu cortex-m0plus
+.thumb
+
+.equ XOSC_BASE, 0x40024000
+.equ CTRL_OFST, 0x0
+.equ STATUS_OFST, 0x4
+.equ STARTUP_OFST, 0xc
+
+.equ CLOCKS_BASE, 0x40008000
+.equ CLK_REF_CTRL_OFST, 0x30
+.equ CLK_SYS_CTRL_OFST, 0x3c
+.equ CLK_PERI_CTRL_OFST, 0x48
+
+.equ RESETS_BASE, 0x4000c000
+.equ RESET_OFST, 0x0
+.equ RESET_DONE_OFST, 0x8
+
+.equ IO_BANK0_BASE, 0x40014000
+.equ GPIO0_CTRL_OFST, 0x04
+.equ GPIO1_CTRL_OFST, 0x0c
+
+.equ UART0_BASE, 0x40034000
+.equ UARTDR_OFST, 0x00
+.equ UARTFR_OFST, 0x18
+.equ UARTIBRD_OFST, 0x24
+.equ UARTFBRD_OFST, 0x28
+.equ UARTLCR_H_OFST, 0x2c
+.equ UARTCR_OFST, 0x30
+
+.equ ATOMIC_SET, 0x2000
+.equ ATOMIC_CLEAR, 0x3000
+
+.type setup, %function
+.global setup
+
+setup:
+
+ // XOSC
+ ldr r1, =XOSC_BASE
+ movs r0, 47 // startup delay for 12Mhz crystal
+ str r0, [r1, STARTUP_OFST]
+ ldr r0, =0x00fabaa0 // enable
+ str r0, [r1, CTRL_OFST]
+1:
+ ldr r0, [r1, STATUS_OFST]
+ lsrs r0, 31 // stable bit
+ beq 1b
+
+ // Clocks
+ ldr r1, =CLOCKS_BASE
+ // Reference clock
+ movs r0, 0x2 // src = xosc
+ str r0, [r1, CLK_REF_CTRL_OFST]
+ // System clock
+ movs r0, 0x0 // src = clk_ref
+ str r0, [r1, CLK_SYS_CTRL_OFST]
+ // Peripheral clock
+ movs r0, 1 // set enable
+ lsls r0, 11
+ adds r0, 0x4 << 5 // src = xosc
+ str r0, [r1, CLK_PERI_CTRL_OFST]
+
+ // Deassert resets for GPIO and UART
+ movs r0, 0b1 << 5 // IO_BANK0 (bit 5)
+ movs r1, 0b1 // UART0 (bit 22)
+ lsls r1, 22
+ orrs r0, r1
+ ldr r1, =(RESETS_BASE + ATOMIC_CLEAR)
+ str r0, [r1, RESET_OFST]
+ ldr r1, =RESETS_BASE
+1:
+ ldr r2, [r1, RESET_DONE_OFST]
+ tst r2, r0
+ beq 1b
+
+ // Configure and enable UART
+ ldr r1, =UART0_BASE
+ movs r0, 6
+ str r0, [r1, UARTIBRD_OFST]
+ movs r0, 33
+ str r0, [r1, UARTFBRD_OFST]
+ movs r0, 0b111 << 4 // 0b11 = word len 8 bits, 0b1 = FIFO enabled
+ str r0, [r1, UARTLCR_H_OFST]
+ ldr r1, =(UART0_BASE + ATOMIC_SET)
+ movs r0, 0b1 // UART enable
+ str r0, [r1, UARTCR_OFST]
+ // Configure GPIO 0 and 1 as TX and RX
+ ldr r1, =IO_BANK0_BASE
+ movs r0, 2 // UART function
+ str r0, [r1, GPIO0_CTRL_OFST]
+ str r0, [r1, GPIO1_CTRL_OFST]
+
+ b octedit
diff --git a/octedit/uart.s b/octedit/uart.s
index e79cbdc..0ab1d20 100644
--- a/octedit/uart.s
+++ b/octedit/uart.s
@@ -3,8 +3,8 @@
.thumb
.equ UART0_BASE, 0x40034000
-.equ UARTDR_OFST, 0x00
-.equ UARTFR_OFST, 0x18
+.equ UARTDR_OFST, 0x00
+.equ UARTFR_OFST, 0x18
.type uart_send, %function
.global uart_send