Haiku's EFI ARM bootloader is hanging calling our kernel entry code.


# Bootloader

Assembly to enter kernel:

/*  status_t arch_enter_kernel(struct kernel_args *kernelArgs,
        addr_t kernelEntry, addr_t kernelStackTop);
    r0  - kernelArgs
    r1  - kernelEntry        (0x4438de04)
    r2  - kernelStackTop     (0x445e0674)
*/
FUNCTION(arch_enter_kernel):

    // We can print 'A' to uart here
    // and it shows up as expected.

    // set the kernel stack
    mov     sp,r2

    // set up kernel _start args
    //mov       r0,r0   // kernelArgs
    mov     r4,r1
    mov     r1,#0   // currentCPU=0

    // call the kernel
    mov     pc,r4

    // return
    mov     r0,#-1  // B_ERROR
    mov     pc,lr
FUNCTION_END(arch_enter_kernel)



Log messages from our bootloader exiting EFI
and entering kernel:

kernel entry at 0x4438de04
Kernel stack at 0x445e0674
System provided memory map:
  0x445e0578-0x40000000  0x0 0x41fa1000 0x0
  0x445e0578-0x41fa1000  0x0 0x44000000 0x0
  0x445e0578-0x44000000  0x0 0x44020000 0x0
  0x445e0578-0x44020000  0x0 0x44023000 0x0
  0x445e0578-0x44023000  0x0 0x442a9000 0x0
  0x445e0578-0x442a9000  0x0 0x442aa000 0x0
  0x445e0578-0x442aa000  0x0 0x4458a000 0x0
  0x445e0578-0x4458a000  0x0 0x445f9000 0x0
  0x445e0578-0x445f9000  0x0 0x4579c000 0x0
  0x445e0578-0x4579c000  0x0 0x474ed000 0x0
  0x445e0578-0x474ed000  0x0 0x47654000 0x0
  0x445e0578-0x47654000  0x0 0x478d5000 0x0
  0x445e0578-0x478d5000  0x0 0x4796b000 0x0
  0x445e0578-0x4796b000  0x0 0x47a97000 0x0
  0x445e0578-0x47a97000  0x0 0x47ab9000 0x0
  0x445e0578-0x47ab9000  0x0 0x47af3000 0x0
  0x445e0578-0x47af3000  0x0 0x47edf000 0x0
  0x445e0578-0x47edf000  0x0 0x47ee5000 0x0
  0x445e0578-0x47ee5000  0x0 0x47fe6000 0x0
  0x445e0578-0x47fe6000  0x0 0x47ff7000 0x0
  0x445e0578-0x47ff7000  0x0 0x47ffc000 0x0
  0x445e0578-0x47ffc000  0x0 0x48000000 0x0
  0x445e0578-0x4000000  0x0 0x8000000 0x0
  0x445e0578-0x9010000  0x0 0x9011000 0x0
Calling ExitBootServices. So long, EFI!
VirtioBlkExitBoot: Context=0x45D0F490
VirtioBlkExitBoot: Context=0x45D1A690
VirtioNetExitBoot: Context=0x47034010
VirtioGpuExitBoot: Context=0x47044210
SetUefiImageMemoryAttributes - 0x0000000047965000 - 0x0000000000006000 (0x0000000000000000)
SetUefiImageMemoryAttributes - 0x000000004795E000 - 0x0000000000007000 (0x0000000000000000)
SetUefiImageMemoryAttributes - 0x0000000047958000 - 0x0000000000006000 (0x0000000000000000)
SetUefiImageMemoryAttributes - 0x0000000047952000 - 0x0000000000006000 (0x0000000000000008)
SetUefiImageMemoryAttributes - 0x0000000047949000 - 0x0000000000009000 (0x0000000000000008)
SetUefiImageMemoryAttributes - 0x000000004793D000 - 0x000000000000C000 (0x0000000000000008)
SetUefiImageMemoryAttributes - 0x0000000047937000 - 0x0000000000006000 (0x0000000000000008)
SetUefiImageMemoryAttributes - 0x0000000047931000 - 0x0000000000006000 (0x0000000000000008)
A



# Kernel

Kernel entry (_start):
 extern "C" int
 _start(kernel_args *bootKernelArgs, int currentCPU)
 {
+       Print B to uart.
+       asm volatile (
+               "mov     r1, #66\n\t"
+               "mov     r2, #0x9000000\n\t"
+               "strb    r1, [r2]\n\t"
+       );


This entry address is definitely correct looking at the disassembly...

Disassemble kernel Entry address in qemu:

(qemu) xp /128i 0x4438de04
0x4438de04:  e92d4810  push     {r4, fp, lr}
0x4438de08:  e28db008  add      fp, sp, #8
0x4438de0c:  e24dd014  sub      sp, sp, #0x14
0x4438de10:  e50b0018  str      r0, [fp, #-0x18]
0x4438de14:  e50b101c  str      r1, [fp, #-0x1c]
0x4438de18:  e59f4464  ldr      r4, [pc, #0x464]
0x4438de1c:  e08f4004  add      r4, pc, r4
0x4438de20:  e3a01042  mov      r1, #0x42
0x4438de24:  e28db008  add      fp, sp, #8
0x4438de28:  e24dd014  sub      sp, sp, #0x14
0x4438de2c:  e50b0018  str      r0, [fp, #-0x18]
0x4438de30:  e50b101c  str      r1, [fp, #-0x1c]
0x4438de34:  e59f4464  ldr      r4, [pc, #0x464]
0x4438de38:  e08f4004  add      r4, pc, r4
0x4438de3c:  e3a01042  mov      r1, #0x42         << print 'B' to uart in top of _start in kernel
0x4438de40:  e3a02409  mov      r2, #0x9000000    << print 'B' to uart in top of _start in kernel
0x4438de44:  e5c21000  strb     r1, [r2]          << print 'B' to uart in top of _start in kernel
0x4438de48:  e51b3018  ldr      r3, [fp, #-0x18]
0x4438de4c:  e5933004  ldr      r3, [r3, #4]
0x4438de50:  e3530001  cmp      r3, #1
0x4438de54:  1a00000f  bne      #0x4438de98
0x4438de58:  e51b3018  ldr      r3, [fp, #-0x18]
0x4438de5c:  e5933000  ldr      r3, [r3]
0x4438de60:  e3002c28  movw     r2, #0xc28


Registers when the lockup occurs:

(qemu) info registers
R00=445f55f8 R01=00000000 R02=821b3000 R03=445f55f8
R04=4438de04 R05=47ac5f85 R06=09010000 R07=00000000
R08=09011000 R09=00000000 R10=00000000 R11=47ab89dc
R12=ffffffd0 R13=00000000 R14=47830704 R15=47830704
PSR=600001d7 -ZC- A abt32
s00=00000000 s01=00000000 d00=0000000000000000
s02=00000000 s03=00000000 d01=0000000000000000
s04=00000000 s05=00000000 d02=0000000000000000
s06=00000000 s07=00000000 d03=0000000000000000
s08=00000000 s09=00000000 d04=0000000000000000
s10=00000000 s11=00000000 d05=0000000000000000
s12=00000000 s13=00000000 d06=0000000000000000
s14=3f4ccccd s15=00000000 d07=000000003f4ccccd
s16=00000000 s17=00000000 d08=0000000000000000
s18=00000000 s19=00000000 d09=0000000000000000
s20=00000000 s21=00000000 d10=0000000000000000
s22=00000000 s23=00000000 d11=0000000000000000
s24=00000000 s25=00000000 d12=0000000000000000
s26=00000000 s27=00000000 d13=0000000000000000
s28=00000000 s29=00000000 d14=0000000000000000
s30=00000000 s31=00000000 d15=0000000000000000
s32=76726553 s33=73656369 d16=7365636976726553
s34=6f53202e s35=6e6f6c20 d17=6e6f6c206f53202e
s36=00000000 s37=00000000 d18=0000000000000000
s38=00000000 s39=00000000 d19=0000000000000000
s40=00000000 s41=00000000 d20=0000000000000000
s42=00000000 s43=00000000 d21=0000000000000000
s44=00000000 s45=00000000 d22=0000000000000000
s46=00000000 s47=00000000 d23=0000000000000000
s48=00000000 s49=00000000 d24=0000000000000000
s50=00000000 s51=00000000 d25=0000000000000000
s52=00000000 s53=00000000 d26=0000000000000000
s54=00000000 s55=00000000 d27=0000000000000000
s56=00000000 s57=00000000 d28=0000000000000000
s58=00000000 s59=00000000 d29=0000000000000000
s60=00000000 s61=00000000 d30=0000000000000000
s62=00000000 s63=00000000 d31=0000000000000000
FPSCR: 60000010