diff options
Diffstat (limited to 'system/arm/simple_bootloader/simple.S')
| -rw-r--r-- | system/arm/simple_bootloader/simple.S | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/system/arm/simple_bootloader/simple.S b/system/arm/simple_bootloader/simple.S index d8f2905e9..afba47728 100644 --- a/system/arm/simple_bootloader/simple.S +++ b/system/arm/simple_bootloader/simple.S @@ -44,7 +44,7 @@ * * Upon executing this code: * r0 = 0, r1 = machine number, r2 = atags ptr - * r3 = kernel start address + * r3 = kernel start address, r4 = GIC address, r5 = flag register address * * CPU 0 should branch to the kernel start address and it's done with * the boot loader. Other CPUs need to start in a wfi loop. When CPU0 sends @@ -56,16 +56,27 @@ .extern main _start: _entry: - mrc p15, 0, r4, c0, c0, 5 // get the MPIDR register - uxtb r4, r4 // isolate the lower 8 bits (affinity lvl 1) - adds r4, r4, #0 // set flags for branch + b bootldr // All the interrupt vectors jump to the boot loader + b bootldr + b bootldr + b bootldr + b bootldr + b bootldr + b bootldr + b bootldr + b bootldr + +bootldr: + mrc p15, 0, r8, c0, c0, 5 // get the MPIDR register + uxtb r8, r8 // isolate the lower 8 bits (affinity lvl 1) + adds r8, r8, #0 // set flags for branch bxeq r3 // if it's 0 (CPU 0), branch to kernel + mov r8, #1 + str r8, [r4, #0] // Enable CPU interface on GIC + wfi // wait for an interrupt pen: - wfi // otherwise wait for an interrupt - mov r4, #0x30 // Build address of the system controller - movt r4, #0x1000 // flag register r4 = 0x10000030 - ldr r5, [r4] // load the value - movs r5, r5 // set the flags on this value + ldr r8, [r5] // load the value + movs r8, r8 // set the flags on this value beq pen // if it's zero try again - bx r5 // Jump to where we've been told + bx r8 // Jump to where we've been told bkpt // We should never get here |