diff options
Diffstat (limited to 'src/boot/boot2.S')
| -rw-r--r-- | src/boot/boot2.S | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/src/boot/boot2.S b/src/boot/boot2.S new file mode 100644 index 0000000..0b61084 --- /dev/null +++ b/src/boot/boot2.S @@ -0,0 +1,38 @@ + .thumb + + .section .boot2, "ax" + + // Disable SSI + ldr r0, =SSI_SSIENR + ldr r1, =0 + str r1, [r0] + + // Set baud rate + ldr r0, =SSI_BAUDR + ldr r1, =4 + str r1, [r0] + + // Enter XIP + ldr r0, =SSI_CTRLR0 + ldr r1, =(3 << 8) | (31 << 16) + str r1, [r0] + + // CTRLR0 + ldr r0, =SSI_SPI_CTRLR0 + ldr r1, =(6 << 2) | (2 << 8) | (0x03 << 24) + str r1, [r0] + + // Enable back SSI + ldr r0, =SSI_SSIENR + ldr r1, =1 + str r1, [r0] + + // Jump to crt0.S + ldr r0, =0x10000101 + bx r0 + + .set SSI_BASE, 0x18000000 + .set SSI_CTRLR0, SSI_BASE + 0x00 + .set SSI_SSIENR, SSI_BASE + 0x08 + .set SSI_BAUDR, SSI_BASE + 0x14 + .set SSI_SPI_CTRLR0, SSI_BASE + 0xF4 |